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M17“? m 'E..“§~;‘m f ' llIWill"!1111111111111111111111llll 3 1293 10558 3128 This is to certify that the thesis entitled ZHE AVAILIBILITY 0F CROP RESIDUE AND ITS POTENTIAL AS A FUEL presented by John Henry Posselius, Jr. has been accepted towards fulfillment of the requirements for M S July 20, 1981 0-7639 degree in AC EGR 'r 6112m- Major professor g MSU LIBRARIES RETURNING MATERIALS: Place in book drop to remove this checkout from your record. FINES will be charged if book is returned after the date stamped below. THE AVAILABILITY OF CROP RESIDUE AND ITS POTENTIAL AS A FUEL BY John Henry Posselius, Jr. A THESIS Submitted to Michigan State University in partial fulfillment of the requirements for the degree of MASTER OF SCIENCE Department of Agricultural Engineering 1982 Cepyright by JOHN HENRY POSSELIUS, JR. 1982 ABSTRACT THE AVAILABILITY OF CROP RESIDUE AND ITS POTENTIAL AS A FUEL By John Henry Posselius, Jr. The problems which could arise if too much crop residue is removed from crOp production land has prompted the development of a computer program that provides scientific guidelines for residue removal. Used with a number of figures and tables the computer program not only determines the amount of crop residue available for removal without putting undue stress on the 3011's productivity but the program also performs an energy balance on the crOp residue removal system. All energy inputs into crap produc- tion, harvesting, post-harvest processes, transportation, nutrient replacement and conversion are accounted for. Through numerous sample runs it has been determined that each field proposed for crop residue removal should be considered on a case-by-case basis. It has also been deter- mined that crop residue from some soils and locations can safely be removed. The major concerns are potential increases in wind and water erosion and damage to the soil SCIUCCUIB . ACKNOWLEDGMENTS I wish to thank all my committee members, Dr. Bill Stout, Dr. George Merva, Dr. "Bus" Robertson, and Mr. Dwight Quisenberry for all the time, support, guidance, and counsel they gave. Also, my thanks go to my colleagues, friends, and family. ii Chapter I. II. III. TABLE OF CONTENTS INTRODUCTION 0 O O O O O C O O O O O O O Dangers in Removing Crop Residue . . . . Erosion . . . . . . . . . . . . . . Soil Compaction . . . . . . . . . Nutrient Maintenance . . . . . . . . . Objectives . . . . . . . . . . . . Scientifically Determined Guide— lines for Residue Removal . . . . . Large Area Analysis . . . . . . . . . Limitations . . . . . . . . . . . . Single Field Analysis . . . . . . . . Large Area Analysis . . . . . . . . LITERATURE REVIEW . . . . . . . .q. . . Soil Requirements for Crop Residue for Continued Crop Production . . . . Water Erosion . . . . . . . . . . . . Wind Erosion . . . . . . . . . . . . . Nutrient Maintenance . . . . . . . Soil Physical Properties . . Energy Inputs to 0.8. Agriculture . Crop Residue Availability . . . . . . Residue Estimates and Collection . . . PROGRAM DEVELOPMENT . . . . . . . . . . Theory and Assumptions . . . . . . . . Residue Needed to Prevent Wind Erosion Residue Needed to Prevent Water Erosion Total Biomass in the Field . . . . . . Residue Available for Uses Other Than Soil Management . . . . . . . . Determining the Net Energy Gain . . . The Transportation System . . . . . iii Nth m c~bw»ra H WV“ 10 10 11 12 14 15 18 19 21 24 24 24 29 31 33 35 37 IV. SINGLE FIELD SAMPLE RUNS . Purpose of Sample Runs . Input Data for Sample Runs . Results of the Sample Runs Usage of Results . . . . . V. RESULTS AND DISCUSSION OF CROP AVAILABILITY PROGRAM . . . . Comparisons with Other Works Versatility of the Program . Wind Erosion Section . . Water Erosion Section . . The Energy Balance . . . . . Limitation of the Program . VI. SUMMARY AND CONCLUSIONS Summary . . . . Conclusions . . . . . . . . . VII. RECOMMENDATIONS FOR FURTHER RESEARCH Program Development Verification of Program APPENDIX A--TABLES . . . . . . RESIDUE TABLE 1--THE EFFECT OF MOISTURE, 0N CORN PLANT GROWTH TABLE 2--SOIL ERODIBILITY INDEX (I) FOR SOILS WITH DIFFERENT PERCENTAGES OF NON- ERODIBLE FRACTIONS AS DETERMINED BY STANDARD DRY SIEVING FERTILITY LEVEL, AND DEGREE OF SOIL COMPACTION TABLE 3--SOIL ERODIBILITY INDEX (I). iv 39 39 39 42 43 46 46 47 48 48 49 50 51 51 52 54 54 55 S7 S7 58 59 APPENDIX TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE TABLE17 10 -AVERAGE N, l3-SOIL ERODIBILITY 14 15 _llmfl 16 4--PREVAILING WIND EROSION DIRECTION 5--MONTHLY CLIMATIC FACTORS "C" FOR EACH COUNTY IN MICHIGAN . . . 6--CROPPING-MANAGEMENT VALUES FOR CONSERVATION TILLAGE, MICHIGAN, LOWER PENINSULA . . . . . . . 7--CROP SPECIFICS o o o o o o o o o o o 8--ESTIMATED RANGE OF FUEL REQUIRE- MENTS FOR SELECTED FARMING OPERATIONS I C C O O C O I O O O O O 9--FUEL CONSUMPTION OF FIELD OPERATIONS IN DIESEL EQUIVALENTS . P, AND K CONCENTRATIONS IN CROP RESIDUE . . . . . . . . . . . Il-INPUT DATA FOR SAMPLE RUNS lZ-RESULTS OF SAMPLE ANALYSIS . . . . "K" TOLERABLE SOIL LOSS VALUES AND "T" VALUES . . -COMPUTED K AND T VALUES FOR SOILS ON EROSION RESEARCH STATIONS . . . . FACTORS FOR DETERMINING LS . . . -EROSION PREVENTION PRACTICE FACTOR "P" O O C O C O O O C O O O O -BIOCONVERSION EFFICIENCIES . . . B--FIGURES . O O O O O O O O I O O O O O O O 0 FIGURE l-Potential soil loss from knolls factor, expressed as percentage of that on level ground: (a) from top of knoll, (b) from that portion of windward slope where drag velocity and wind drag are the same as on top of knoll (from about the upper third of the lepe) . 60 61 65 66 67 7O 71 72 74 75 77 77 78 79 80 80 FIGURE 2-Soil ridge roughness factor chart determines soil ridge roughness factor "K" from the soil ridge rough- ness . . . . . . . . . . . . . . . . 81 FIGURE 3-Annual climatic factor "C" (percen- tage) based on the average wind velocity and on the precipitation evaporation index . . . . . . . . . . 82 FIGURE 4-Chart to determine soil loss E4. E4 - I'K'C'L' from soil loss E2 - I'K' and E - I'K'C' and from unsheltered distance L' across the field . . . . . . . . . . . . . . . . 83 FIGURE S-New method of determining E4 from E2, E4, and E21 . . . . . . . . 84 FIGURE 6-Vegetative equivalent chart to determine soil loss E - I'K'C'L'V from soil loss E - I'K'C’L' and from the vegetative cover factor, V. The chart can be used in reverse to determine V needed to reduce soil loss to any degree . . . . . . . . . 85 FIGURE 7-Residue for small grain stubble‘ including stover. Chart to determine V from R' or R' from V of standing and flat anchored small grain stubble with any row width up to 10 in., including stover . . . . . . . . . . . . . . . 86 FIGURE 8-Residue for grain sorghum and corn. Chart to determine V from R' or R' from V of standing and flat grain sor- ghum and corn stubble of average stalk thickness, leafiness, and quantity of tops on the ground . . . . . . . . . 87 FIGURE 9-Method for determining the actual soil erodibility factor . . . . . . . 88 FTCURElO-Average annual values of rainfall erosion factor . . . . . . . . . . . 89 vi FIGURE ll-Three-dimensional view of Figure 6 . . . . . . . . . . . . . . 90 APPENDIX C--CROP RESIDUE AVAILABILITY PROGRAM . . . 91 APPENDIX D--CROP RESIDUE AVAILABILITY PROGRAM, SECTIONS TWO-SIX . . . . . . . . . . . .106 BIBLIOGRAPHY O O O O O O O C O O O O O O O O O O O O 118 vii CHAPTER ONE INTRODUCTION Dangers in Removing Crop Residue There are few natural resources of greater importance to mankind than the soil. In fact, it has been said that ". . . human vanity can best be served by a reminder that whatever his accomplishments, sophistications or artistic pretensions, mankind owes his very existence to a six inch layer of topsoil". The six- to twelve-inch layer of topsoil contains the nutrients which feed the crap, and its proper maintenance determines the success of the entire agricultural endeavor. While it is a very slow process for nature to build up the topsoil, it is often destroyed very rapidly. The de- terioration of productivity is usually a result of agricultural mismanagement. One of the agricultural practices which most severely affects that top layer of soil is the removal of too much of the above-ground crop. The removal of too much of the total crop is becoming a more and more serious concern. In the past few years crop residue has received much attention as a potential energy source (Alich and Inman, 1974; Lipinsky, 1978; Steffgen, 1974). It has been shown that crop residue is a good source of energy, either burned directly for heat or converted into gaseous or liquid form for fuel. However because of low density and wide distribution the temptation of collecting too much residue from one location must be resisted. If not, depletion of the topsoil's productivity may occur. Scientists generally do not advocate total removal of crOp residue from the soil, for it is recognized that it is essential for soil erosion control and maintenance of pro- ductive capacity. Therefore, when utilization of crop residue for purposes other than soil maintenance is proposed, the first question scientists confront is, "To what extent can crop residue be removedeithout adversely affecting soil conservation and reducing productivity?" In addition, when crop residue is proposed as an alternate source of energy, it must be determined whether it can be grown, harvested, collected, transported, converted to a more useful form, and utilized while maintaining a positive energy balance. In addressing the question, "How much residue can be safely removed?" the following theoretical primary functions of residue are recognized: -- provide surface protection from erosion -- act as a storehouse of nutrients -- stabilize structure and improve tilth -- reduce bulk density -- enhance water infiltration and moisture retention -- provide energy for microorganism activity -- increase cation exchange capacity -- release carbon dioxide. Because commercial fertilizers are readily available to perform some of these functions, above-ground residue primarily provides surface protection, helps maintain the soil structure, improves water infiltration and reduces evaporation. The crOp roots also play a role in fulfilling the soil requirements. Erosion Erosion is a process whereby, under the forces of wind and water, topsoil particles are detached from the surface and transported to a new location. While some tapsoil loss from erosion in unavoidable, at tolerable levels it will permit crop production to proceed and the 3011's productivity to be maintained, or perhaps increased, over time. The amount of soil loss tolerance denotes the maximum level of soil erosion that will permit crop productivity to be sustained indefinitely. Those factors which determine the soil loss tolerance include soil depth, physical properties and other characteristics affecting root deve10pment, gully prevention, on-field sediment problems, seeding losses, soil organic matter deductions and plant nutrient losses (Wischmeier and Smith, 1978). One of the elements whichkeeps both water and wind erosion within the tolerable soil loss limit is the amount of crop residue on the surface. Crop residue has the tendency to trap detached soil particles and significantly reduce their transport. The residue also breaks the impact from raindrops and prevents wind from disloding soil particles. Soil Compaction Besides erosion, soil compaction is a major concern when residue removal is proposed. Soil compaction is an ever-increasing problem with introduction of larger and heavier agricultural machinery. As the soil is compacted, the bulk density increases, root growth becomes inhibited, which reduces tap growth. The higher the bulk density the less defined the structure and the smaller the pore space. This decreases the amount of oxygen and water infiltration, which in turn increases water runoff. With the resulting compaction more power is required to prepare the seed bed. Plant roots are the prime source of residue that combat poor soil structure. When roots alone are insufficient, above-ground residue is also needed. Nutrient Maintenance As a result of increasing use of commercial fertilizers, the relative importance of crop residue as a nutrient has been de-emphasized. Where crop residues and manure are the primary sources of plant nutrients, through microbial action, the nutrients are released and utilized by the crops. When commercial fertilizers are used, the crOp residue, particularly those high in carbon and low in nitrogen that are left on the field have a tendency to tie-up the nutrients through micro- bial decomposition. The resulting nitrogen deficiencies occur mostly during the spring and early summer when the previous year's residue are decomposing (Allison, 1973). It should be noted that if not enough residue is left on the soil and erosion therefore increases, the commercial fer- tilizers will be lost with the soil. Objectives The problems which could arise if too much residue is removed have prompted the development of a computer program that will provide scientific guidelines for residue removal. To make this program accessible to the group of people most likely to be harmed by excessive removal of crop residue -- that is, farmers, it was designed to be used on a Texas Instrument's TI-59 programmable calculator. Many cooperative extension offices now have this equipment and trained personnel who can apply it to specific farms. Used in the same fashion as an ordinary calculator, it can be programmed to perform the necessary calculations to determine how much residue can be removed without exceeding soil loss tolerance. Scientifically Determined Guidelines for Residue Removal The program consists of the six following sections: Section 1 - Wind Erosion Analysis; Section 2 — Water Erosion Analysis; Section 3 Total Biomass in the Field; Section 4 - Residue Available for Removal; Section 5 - Energy Balance Analysis; Section 6 - The Transportation System. The Wind Erosion Section is based on the wind erosion equation, developed and verified by Woodruff and Siddoway. The Water Erosion Section is based on the water erosion equation developed and verified by Wischmeier and Smith. The other sections determine the total above-ground residue that may be removed based on crop yields, the nutritive value of the residue and a total energy balance. With the use of the water and wind equations the computer program cal- culates the amount of above-ground crop residue needed to keep erosion within tolerable limits. It is through an intuitive knowledge of the 3011's structure that one deter- mines the amount of residue required to maintain optimum bulk density. All these data, manipulated within the program, determine how much excess above-ground crop residue exists. By knowing the amount of excess residue and the current agri- cultural practices, the net energy can then be determined as can the amount of nutrient being removed with the crop residue. The program was designed primarily for individual field analysis, with the best scientific guidelines available. It is simple to use and will give relatively conservative tolerable removal rates for actual crop residue removal. LargegArea Analysis Although the system can be used for areas larger than single fields, when used for areas much larger than a 65 ha (160 ac) field it should be noted that the output data are rather general. The program works well for estimating the residue available from larger pieces of land, i.e., counties, land resource areas, and so on. However, the larger the area, the more averaging and generalization of the input data must be made. Limitations Single Field Analysis The model developed by the computer program is limited by how closely the data in the tables and figures represents actual field conditions. An example of the error- margin inherent in these input data would be with regard to the slope and length of slope factors used in the water ero- sion equation. This factor is a function of the gradient and length of the slope. The problem is one of uniformity. If the slope is uniform there will be no variance between the computer-determined LS and the actual field condition. If the slape is not uniform, however, which is generally the case, the LS factor will differ from the actual field conditions. Another limitation is the energy data. The energy data used in this program has been determined either by energy audit (Myers et al., 1980) or by calculation (White, 1974). The figures represent the average energy requirement for specific tasks (for example, 14.0 l/ha to combine corn). The problem with this data is that the conditions for the field being analyzed and those of the input data in most cases will be different, in terms of yields, equipment used and condition of the equipment and/or field. Another limitation is residue-to-grain ratios. The residue-to-grain ratio is used to determine the amount of above-ground residue based on the established yield per unit of land. Though these figures are averages it is very unlikely that a corn yield of 1235 kg/ha (120 bu/ac)_grown in Northern Michigan with a particular hybrid will have exactly the same amount of above-ground residue as a crop of corn with a similar yield grown in lower Michigan. There- fore, when using this program, interpolating on the conserva- tive side is advisable. For example, if a slope in a parti- cular field is not uniform, use of an L8 factor that is a little steeper than the average slope of the field being analyzed is recommended. Being on the conservative side should help avoid future problems with the 3011's productivity. Large Area Analysis When using this program for areas much larger than 65 ha these limitations are compounded. Not only is it difficult to estimate an LS factor for a field one square kilometer in size, but even harder to come up with an average soil type or agricultural system that is uniform for the total area. The method of minimizing these problems will be dis- cussed in the "user'sgmides" in the Appendix. A full ex- planation of all assumptions and interpretation of the results will also be discussed, as will sample runs. 10 CHAPTER TWO LITERATURE REVIEW Soil Requirements of Crop Residue for Continued Crop Production The potential of crOp residue as an alternate source of energy is immense (Alich and Inman, 1974; Lipinsky, 1978; Steffgen, 1974). In these reports, however, it has been implied that the crop residue are waste products of agri- cultural production. This is not the case. As reported by Lindstrom et al., (1979) crop residue influences soil properties, both physically and chemically, as either stable or unstable soil organic matter. This is an important factor in maintaining soil productivity. Crop residue retains plant nutrients and helps maintain soil porosity and tilth for easy soil tillage and good plant growth. When removed, residue takes with it large amounts of nutrients that must be replaced by mineral fertilizers or other sources, such as animal manure (Larson, 1979). Residue removal also inhibits water infiltration, and affects soil water storage and plant use (Larson, 1977). Left on the soil surface, residue curtails soil detachment by raindrOp impact and reduces the velocity of runoff, which reduces the runoff's potential to detach and transport soil (Wischmeier, 1975). 11 Water Erosion In a 1960 report, Wischmeier states that a "highly significant inverse correlation between crOp yields and erosion losses was found. This report represents the results of a series of more or less independent studies of specific phases of soil and water management at 37 locations in 21 states over a 30-year period. This 30-year study, along with the previous works of other soil scientists and engineers, led to the development of a universal soil loss equation (USLE), which reflects the effects of locality differences in rainfall patterns. Over time, the USLE has been improved and verified, the variables that make up the equation being modified and improved. "Predicting rainfall erosion loSses, a guide to conservation planning" (Wischmeier and Smith, 1978) describes the USLE's current use. The USLE is "an erosion model de- signed to predict the longtime average soil losses in runoff from specific field areas in specified cropping and manage- ment systems." Given an accurate selection of its factors, the equation will compute the average soil loss for a multi- crop system, or for a particular crop year in a rotation. Wischmeier and Smith (1978) indicate that widespread field use has substantiated its value and validity for this purpose. Even though the USLE has been validated work is con- tinuing to increase the equation's usefulness and accuracy. Rawls et al. (1979) studied the effects of conservation 12 tillage on SCS runoff curve numbers. The study did not generate enough data to derive an equation for predicting the effects of conservation tillage on runoff. It was established however, that the use of conservation tillage will affect the cropping-management factors by reducing run- off. Other work on the USLE has been done in Iowa. Taylor and Amemiya (1980) developed a computer program that can be used on the TI-59 programmable calculator, which solves the USLE as it is given in Agricultural Handbook Number 537, USDA 1978. This program not only calculates the annual soil loss but it also determines the cropping-management factor that is required to keep yearly soil loss within tolerable limits. Wind Erosion The problem of soil erosion is not limited to rain and water runoff as the detachment and transport medium. As re- ported by Hill (1966), wind erosion on upland crop soils is occurring at an increasing rate in Michigan. In 1965, based on nearly 30 years of research, and equations developed by various soil scientists and engineers, Woodruff and Siddoway developed what is the basis for the wind erosion equation (WEE) now used by the Soil Conservation Service (SCS). Since Woodruff and Siddoway's work, much has been done to simplify, verify, and extend the WEE, not all of it entirely successful. 13 lisliderule was developed by the SCS, the Agricultural Re- search Service, and the Graphic Calculator Company, which was easier to use than the original equation. This sliderule method of determining soil loss by wind erosion has been in use since the early 19703. Leon Lyles, USDA, SEA-AR and Dwight Quisenberry, SCS, report that as of June 1981 the sliderule system should not be used (personal communication). It seems that when the sliderule was developed, a particular scale required to determine the E4 factor was assumed to be logarithmic. The scale was not logarithmic nor was it linear. Rather, it was based on actual field data developed by Wood- ruff and Siddoway. Other attempts to improve the WEE have been more suc- cessful. Lyles and Allison (1980) were able to develop the equivalent residue factors for a number of crops that will work in the WEE. As mentioned in "How to Control Wind Erosion" (Woodruff et al., 1977), "Good vegetative cover on the land is the most permanent and effective way to control wind erosion." Living or dead, standing or flat, the vege- tative matter protects the soil surface from wind action by reducing wind speed and by preventing much of the direct wind forces from reaching erosive soil particles. The crop residue will also trap soil particles that are being trans- ported, which in turn prevent the normal avalanching of soil material downwind. Soil erosion by wind was generally considered to be limited to semi-arid and arid regions. It has been now found 14 to be a problem wherever soil, vegetative, and climate condi- tions are conducive. Some such conditions are as follows: (1) the soil is loose, dry, and reasonably finely divided; (2) the soil surface is smooth, bare or sparsely covered with crop residue; (3) the field is sufficiently large; and, (4) the wind is strong enough to move the soil (Skidmore and Siddoway, 1978). One computerization of the wind erosion equation, that of Skidmore et a1. (1970), contains a program to be used on a mainframe computer system in Fortran IV. The solution is similar to the manual method developed by Woodruff and Siddo- way (1965). A problem with this program as well as one developed by Lyles, is that the wind erosion analysis of a particular field cannot be performed by the field worker on the initial visit to the site under investigation. However, the elimination of a nomograph with a movable scale makes these programs easier to use than the manual method and increases the accuracy of the computations. The method of-analyzing wind erosion used by the SOS has also been improved over the original WEE. Instead of graphs and nomographs with movable slides, the 803 method depends on numerous tables (SOS-Mich, 1978). Nutrient Maintenance Larson et al (1976) conclude that the nutritive value of the residue represents an appreciable portion of the total 15 commercial fertilizers applied. However, when considering 2311 the nutrient value of the residue it is generally more economical to provide necessary nutrients via commercial fertilizers. Normally, if a leguminous crOp is turned under, about 45 kg/ha (4O lb/A) of nitrogen is made available to the succeeding crop. This seldom provides the total nitrogen re- quirement. And, when straw, corn stover or other crop residue low in nitrogen are incorporated into the soil, microorganism activity ties up most of the available soil nitrogen. If the roots constitute the only new residue source for humus main- tenance, few problems exist. But where large amounts of both tops and roots are present a sufficiently wide carbon-nitrogen ratio may cause nitrogen deficiencies during rapid decay in spring and early summer (Allison, 1973). Removing all above-ground organic matter and increasing the fertilizer rate will not only maintain soil fertility but, in many cases, increase it (Anon., 1964; Allison, 1973; Barber, 1978; Larson et al., 1971; Tisdale and Nelson, 1975). This does not mean residue are not required for total soil maintenance, rather just not necessary for maintaining soil fertility. Soil Physical Properties Crop residue functions in soil maintenance as more than just erosion control and nutrient supplement. The residue also reduce the bulk density of the soil, enhancing infiltration, moisture retention and respiration. Cation exchange capacity, 16 aggregation and tilth maintenance are also increased by its presence. Unlike residue used for soil protection or nutrient maintenance, no easy equation or multiplier factor exists for determining the exact requirements needed to maintain ideal physical soil properties. Many studies substantiate the necessity of residue for soil maintenance but figures vary significantly for each soil type and management practice. According to Allison (1973), root residue represent a major source of organic matter available for humus maintenance for a large portion of Ameri- ca's farming areas. The amount is usually inadequate to maintain humus content at high levels but will maintain the level commonly reached after 50 or more years of continuous farming. By this time, the humus level stabilizes at 30 to 50% below virgin levels. It is still adequate for many soils, especially with fertilizer supplements available. The in- creased plant growth due to fertilization increases the amount of root residue which, in turn, keeps humus at an acceptable level. Soil organic matter has increased where abundant plant food has been added under proper conditions. After 12 years of experiments on a field near Lafayette, Indiana, Barber (1979) reached similar conclusions. He stated that, "soil productivity as measured by average corn yield, in years 6 through 11 was not affected by removal of residue . . . hence, we conclude that the plant roots materially con- tribute to maintenance of organic matter level of the soil." 17 After 13 years of field experiments in which five different types of biomass and amounts of O to 16 t/ha/yr were applied to a Marshall silty loam, Morachan et a1. (1971) reported that "it was not visually evident that sig- nificant changes occurred in soil tilth because of treatment differences.‘ Although "wet-aggregate stability and water retention were significantly increased with increasing residue content of the soil, and bulk density was significantly decreased," this soil type is a "medium texture, highly aggre- gated soil that seldom exhibits soil physical problems in the field". The fact that tilth was not apparently improved could be due to natural physical soil properties. Increased bulk density of the soil due to soil compac- tion is well documented. Foth (1978) reported that root extension is inhibited when bulk density exceeds 1.6 g/cc. The higher the bulk density the more poorly defined the struc- ture, and the smaller the soil space. This is usually re- flected in restricted plant growth. Reduced top and root corn plant growth resulting from soil compaction is documented in Table l (Bertrand and Rohnke, 1957). Resistance to root penetration is only one aspect limiting growth in high bulk density soils. Of equal or greater importance is the reduced amount of oxygen in these soils (Tisdale and Nelson, 1975; Foth, 1978). Tisdale and Nelson (1975) found 1.4 to 1.7 g/cc to inhibit seedling emergence; personal communication with Dr. Robertson in 1980 18 indicated he thought the threshold bulk density is about 1.3 g/cc. Furthermore, when bulk density increases from 0.90 to 1.30 g/cc, corn root growth decreases linearly (Phillips and Kirkham, 1962). Compaction due to low organic matter adversely affects farming income as well. A $175/ha and $150/ha reduction in income was reported for no-till and spring moldboard plowing, respectively, when 502 of the stover from a continuous corn operation was harvested (Holtman et al., 1979). It was con- cluded that low organic matter and more trips over the field increased the bulk density of the soil. Lucas and Vitosh (1978) also reported significant changes in crop yield and other physical properties due to changes in soil organic matter content based on different manure applications, crop- ping systems, soil texture, erosion and tillage practices. Often, under revised cropping systems, soil structure and yields are improved while farm energy requirements may be reduced (Robertson, 1952; Anderson et al., 1975; and Robertson and Mokma, 1978). Energy Inputs to U.S. Agriculture As the fuel and energy situation became more critical, farmers, fuel suppliers, and others concerned with agricultural production needed a more complete report of information esti- mating fuel requirements for specific farming operations and overall operations of the total farm enterprise. White (1974) 19 has compiled such a report. This report mentions that the fuel requirements for a specific operation vary widely from one section of a state to another, and even from one farm to another. This is due to such factors as weather, soil struc- ture, topography, depth of tillage, and condition of machinery. White's data are substantiated by Berge (1974) and by Hunt (1977). Berge (1974) has not indicated how his data was ob- tained but Hunt (1977) states that the data presented is "compiled from many sources, including estimates." Hunt thereby attempts to provide a range within which 90% of all actual operations fall. Two farm energy audits which substantiates the above study were performed by Myers et a1. (1980) and Kramer and Shelton (1978). The Myers et al.(1980) report was based on over 50 farm years of data for over 30 different field operations. Crop Residue Availability Lipinsky (1978) predicted the energy potential of bio- mass for the U.S. at 10% or more of current usage. This estimate, however, includes crops grown specifically for energy. An average of seven dry metric tons/ha of corn stover removed from half of America's corn crop (about 13 million hectares) could produce one quad of energy. Lipinsky indicates that it would be detrimental to the soil to remove more than half of these residues (Lipinsky, 1978). 20 About 360 to 590 million metric tons (400 to 650 million tons) of residue are produced annually from the nine leading crops in the U.S. (Larson, 1979; Alich and Inman, 1974). The majority of these residue come from corn, wheat and soybeans. If all of these residue were available for fuel, the potential energy content would be about 8 x 1014 kcal (4 x 1015 Btu) or only 52 of the energy used in the United States in 1977 (75 quads). Larson (1979) suggested that realistically crop residue could provide 1 or 2% of the U.S. energy demand. Larson's estimate was based on current cropping practices and technology. Larson appears to include additional fertilizer, but other energy inputs into the systemare not mentioned. The study is based primarily on the water erosion equation and computed over 100,000 times to fit various conditions. Larson also pointed out the necessity of crop residue for preventing wind erosion and maintaining nutritive value, soil porosity, tilth maintenance and water utilization. Soil scientists do not agree, however, that the residue required to reduce erosion to a tolerable level will adequately maintain the 3011's physical properties. In addition to Larson (1979) there are several updated and comprehensive reports in this area (Gupta et al., 1979; Lindstrom et al., 1979; Campbell et al., 1979; Allmaras et al., 1979, Skidmore et al., 1979; Dusted and Otterby, 1979; and Holt, 1979). After reviewing the computer program used 21 for most of this work (Larson, 1979b), this writer found it was the only practical way to obtain an overview of the potential of crop residue. Larson et al., concluded that soil maintenance should be a prime consideration. Then, "if soil needs can be met with partial or near full removal of crop residue (along with adequate fertilization and other feasible chemical practices), there should be no objection by agriculture to their removal" (Larson, 1979). However, these predictions do not offer a practical guide for residue removal or for determining net energy gain for the farmer. Residue Estimates and Collection The concept of removing crop residue from the soil according to specific guidelines implies a need to determine the actual amount of residue a field requires for its surface to be protected. The SCS has three ways of making these estimates: sightings by experienced personnel, field measurements, and computations using crop yield. Ditson (1980) has compiled a "packet" that explains how to perform two in-the-field methods of measuring crop residue, and has included over a half dozen photographs of fields containing known amounts of residue for reference in making visual estimates. Ditson describes two methods of measuring crop residue: (1) collecting, drying, and weighing crop residue from three sample plots that are one square yard each. The total weight in ounces ismultiplied by 100 22 to determine the pounds of dry residue per acre. (2) The line-point technique. This method consists of observing 100 equally-spaced points along a 50- or lOO-foot line or tape at three random locations in the field. Each point where the line touches a leaf, stem, or stalk from the previous crap is counted. The average number of points touching crop residue is equal to the "percent cover" which is translated into pounds of residue per acre with the aid of Figure 10 in the Agricultural Handbook #537 (Wischmeier and Smith, 1978). The method used to estimate the amount of crop residue left on the surface by use of the crop yields is not effective when residue are to be removed. In the yield method it is assumed that all residue remains in the field. The tillage practices and type of equipment used will determine how much crop residue will remain on the sur- face. (In his Technical Guide, Ditson does not cite sources for these methods.) Very little analysis exists of the percentage of loss from harvesting equipment in crop residue removal for the simple reason that there is virtually no machinery designed specifically for the removal of crop residue, such as corn stover. Small grain straws can be harvested with close to equal efficiencies as hay but there is more shatter loss. As reported in AG Energy (1981), work by C.B. Ritchey and others at Purdue have analyzed the performance of both a big round baler and a hay stacker in collecting corn stover. 23 The residue were windrowed after being cut with a flail pick- up. The researchers found that they could not chop the stalks too close to the ground because the machinery picked up too much soil. The optimum setting was about 7.6 cm above the ground. At the 7.6 cm height in a field with a grain yield of 8800 kg/ha the windrow yields were 775 kg/ha (dry). The material left in the field was 380 kg/ha (dry). Applying the "rule of thumb" for corn that for each pound of grain there is a pound of stover, then about 275 kg/ha disappeared. It was assumed that this loss was caused by shatter losses from the combining and windrowing. On the average, about two-thirds of the material was collected in the windrow. This varied from 82 to 34 percent, depending on the amount the residue were trampled during combining. When the material was bailed an unexpectedly high loss was encountered. With either of the packaging systems only half of the material in the Windrow was accounted for in the bales, and when trans- ported and stored, another 23% loss resulted. 24 CHAPTER THREE PROGRAM DEVELOPMENT Theory and Assumptions The computer model developed to be used in a TI-59 programmable calculator is actually comprised of two programs, both consisting of two magnetic cards. The first program is used to determine the amount of residue required to keep soil loss due to wind erosion within tolerable limits. The second program analyzes the water erosion con- straints to residue removal, measures the minimum above- ground residue which must remain on the soil after the combined loss from wind and water erosion in order to satisfy the 3011's residue requirements, and performs an energy balance on the total system. What follows is a des- cription of each section of the program, including assump- tions made during development and limitations or inaccuracies introduced with the input data. Residue Needed to Prevent Wind Erosion The first section of the program, Section 1, the Wind Erosion Section, is based strictly on "A Wind Erosion Equation" (Woodruff and Siddoway, 1965), and "Wind Erosion Control" (SCS, 1978). The Soil Conservation Services (SCS) publication 25 "Wind Erosion Control" is a technical guide prepared to make the wind erosion equation easier to use. In the SCS system there are many tables and much interpolation. There- fore, starting with the original wind erosion equation which is E - f(IKCLV) where; E - predicted average annual soil loss (in tons per acre per year) HI I a function of I - soil erodibility index K 8 soil ridge roughness factor C = climate factor L - unsheltered field length in the direction of the prevailing wind V a vegetative cover The program has been developed to do most of the calculations. This reduces the time required to perform a field analysis and lessens the number of charts and tables. The initial portion of the program is very straight- forward. The soil erodibility index I (Tables 2 and 3) is multipliedby the knoll factor (Figure 1), and the soil ridge roughness (Figure 2) factor K. These three components are what comprise the E2 factor, which is multiplied by the climate factor C (Figure 3 or Table 4) to determine E3. The E2 and E3 factors are intermediate numbersused in the pro- gram. The computer then recalls the appropriate segment of Figure 4,finds the two curves on either side of the E2 and 26 through two interpolations approximates the appropriate curve for the E2. By breaking down curves 30 through 310, by 20's, i.e., 30, 50, 70, 90, and into four segments, based on the calculated distance, 10 to 60, 61 to 500, 501 to 1500, 1501 to 5000, a straight line was used to approximate these sections (Figure A). With the curves broken down into four sections the accuracy of the line segment replacing the curve is well within half the last significant figure. That is, the numbers calculated via the interpolation of line segments is more accurate than a visual reading of the movable scale in Figure 4. Due to limited capacity, the TI-59 calculator stores the slope and intercept of the line segments for distances 10 to 60 and 61 to 500 in one memory for each of the curves and the slopes and intercepts for segments 501 to 1500 and 1501 to 5000 have been stored in a separate memory. The slopes and intercepts are stored as follows: each memory can hold a ten digit number. For the line segment from 10 to 60 and 501 to 1500 the intercept and slope are the five digits to the left of the decimal. The intercept and slope of the line segment 61 to 500 and 1501 to 5000 are stored to the right of the decimal. Using a "B" to denote the intercept and an "M" to denote the slope, a memory location would appear as follows: BBMMM. BBMMM. The slope and intercepts for the two line segments that 27 surround the line segment E2 are then called and the line segment depicting the curve E2 is then calculated through an interpolation. Though the scale that represents E2 is not linear nor logarithmic, an interpolation between two curves within 20 units from each other will be more accurate than can be read off the scale. The calculated distance that determines the E2 on the E2 curve is calculated in the computer program automatically by dividing the length of the field by the cosine of the deviation of the erosive wind. Then a series of "if, then" statements establishes the correct portion of the curve to be on. At this point the calculator has pre- dicted the E2, E3, and the E2 which was dependent on the calculated distances. With the aid of Figures 5 through 8, the amount and condition of crop residue required for pro- tection is predicted (for actual user-instructions, program listing, and explanation, see Appendix 2). Some of the larger errors in predicting the amount of above-ground residue required to reduce wind erosion to an acceptable level are the environmental factors that are entered into the program. Starting with the soil erodibility index ("I" factor), there are generally only six different numerical values used to describe virtually any soil in Michigan (Table 3). A more accurate "1" factor can be determined by finding the dry soil fractions that are greater than 0.84 mm through a standard dry sieving process. 28 The percentage of soil fractions greater than 0.84 mm is then used with Table 2. The knoll erodibility factor "Is" is used to account for or analyze the erosiveness of knolls 150 meters long (500 ft) or less. The slope of the knoll and Figure 1 is used. The greater the slope the more effect it will have on the "Is" factor. As can be seen in Figure l, the relationship is not linear. There is not too much error introduced with the soil roughness factor "K" if the field surface is very uniform. By measuring the ridges or small undulations, and with the use of Figure 2, the "K" factor is predicted. The climatic factor "C" is given in Figure 3 (or Table 5), which has been determined by a relationship between the mean annual wind velocity for a particular location corrected to a standard height and the effective moisture. Because of the relatively few locations where the climatic data is collected, the predicted soil loss, using this "C" factor, will be less accurate for yearly predictions than it will for the ten year predictions. It is also for ten year periods that the allowable soil loss has been determined. The amount of residue needed to keep the wind erosion under control is very sensitive to the calculated field distance for fields less than 30 meters long. Fields much greater than 30 meters do affect the amount of soil eroded but the actual field length does not have to be measured very'accurately. 29 Residue Needed to Prevent Water Erosion The water erosion equation, better known as the Universal Soil Loss Equation (USLE), (Wischmeier and Smith, 1978) is a much simpler equation to compute, but as is the case in the wind erosion equation, the variables and tolerable soil loss figures are for predicting long range trends and are not a means of analyzing the effects of individual weather phenomena. The equation is as follows: A - RKLSCP, where A - computed soil loss per unit of land R - rainfall and runoff factor K a soil erodibility factor L - slope-length factor S - slope-steepness factor C a cover and management factor F a erosion prevention practice factor Because these factors are multiplied by each other the programming of this particular equation is simple. The "L" and "S" factors combine to become the "LS" factor by the following relationship (Wischmeier and Smith, 1978): LS - (x/72.6)In (65.41 sinze + 4.56 sine + 0.065) A - slope length in feet 6 = angle of slope a arctan of slope steepness m - an exponent that varies with gradient (Figure 15) The program multiplies all the variables andstores the first four. This is done so that different "C" and "P" 30 factors can be tried in an attempt to lower the predicted water erosion below the allowable limit. It should be noted that to be safe when a particular field is being analyzed the predicted soil loss due to water erosion com- bined with the predicted soil loss due to wind erosion must be lower than the tolerable soil loss. The variable that will introduce the most error in this equation will be the "C" factor. If a "C" factor is used from Table 6, it must be recognized that the value will be an approximation of conditions in the field. The reason is that the "C" factor is based on the relationship of several factors: (1) crop stage (in terms of its maturity and canopy cover); (2) crap rotation; (3) quality and quan- tity of the crop residue; (4) the tillage practices and, (5) climatic conditions. The "R" factor, like the wind erosion climatic factor is based on long-term weather averages. Data are collected throughout the state and inter- polations are performed to find the "isoerodents" -- that is, plotted lines on a map that connect locations with equal rainfall erosivity. The soil erodibility factor "K" is similar to the soil erodibility factor for the wind erosion equation in that very few "K" factors are used to depict different soil types. The "K" factor is based on the percentage of silts and very find sands, organic matter, soil structure and soil permeability. If the soil breakdown is determined, the "K" 31 factor for the specific soil can be calculated with the following equation (Wischmeier and Smith, 1978): 100 K - 2.1 Ml-l4(10'4)(12-a) + 3.25 (b-Z) + 2.5(c-3) where the silt fraction does not exceed 70%: M = (silt Z + very fine sand Z) (100 - clay Z) a a percent organic matter b - structure code (Figure 9) c - profile permeability (Figure 9) The "P" factor applies if the field slope is great enough to necessitate either contour farming or strip crop practices (Table 16). Terracing is also a practice that can be used to reduce the total amount of soil loss due to water erosion. However, the practice is used very little in this part of the country. If there is no special erosion prevention practice "P" - 1. It should be noted that both the water erosion and wind erosion sections of the program can be used independently of the rest of the program. Total Biomass in the Field In order for the computer program to accurately pre- dict the annual amount of removable residue over the long run, the residue-to-grain ratios (Table 7) must be accurate for the field being analyzed. A small deviation from the actual residue—to-grain ratio for a specific hybrid will make a large difference whenanalyzing a 60 hectare field with yields of 6300 kg/ha per hectare. It is understood 32 that these ratios are just "rules of thumb," and that the actual relationship between the above-ground residue and grain is not a linear one. The effect this assumption has on the total agricul- tural system being analyzed is minimal as far as the soil's maintenance is concerned. But it has major implications in regard to the overall energy balance. To minimize the ill effects to the soil's productive capacity in using the results of this program, the amount of above-ground residue in the field which is determined to be necessary by the water and wind erosion analysis should be left, instead of removing the amount of crop residue this program predicts will be available. In following this procedure it is assured that an adequate amount of residue is left in the field. Because the residue-to-grain ratios are based on national averages, this procedure becomes especially advisable when the crop yields are much higher than the average and when the growing season is shorter than average. In this section the program reduces the grain yield to a dry weight basis, with the input of either estimated or actual crop yield, and moisture content at the time of reporting. The dry weight is then used with the above-ground residue-to-grain ratio to calculate the total dry above- ground residue. Using the total amount of dry residue the energy content of the residue is determined by assuming an energy content of 1.60 x 104 kJ/kg (7000 Btu/lb). 33 Residue Available for Use§ chgr Than Soil Management In determining the amount of residue available there are three options: the first will predict how much above- ground residue is available after soil maintenance require- ments are met. The total amount of above-ground dry matter is recalled from Section 3, the grain component is subtracted, and the amount of residue required for soil maintenance is subtracted. This calculated amount of residue is then used in the following section to determine the energy balance of the system. The second option of this section determines what the grain portion of the total yield is on a dry weight basis and then proceeds to the following section for the energy balance of the grain production. For this option either the total expected or actual yield is entered or the portion of the yield to be used for alternate energy and the amount of dry matter is calculated by removing the percentage of mois- ture at crop yield reporting. For example, if a field has a corn yield of 6300 kg/ha (100 bu/ac) and half of the crop will go toward alcohol production, then 3150 kg/ha (50 bu/ac) would be entered. The program would recall that moisture content for corn at yield reporting is 15.52 and from this determine the total dry matter available. The third option is used when just a portion of the total above-ground residue is to be used. One instance would be utilizing just the corn 34 cobs. The weight of cobs per bushel of grain is entered, the reported yield is recalled from Section 3, and the pro- gram then determines the weight of cobs on a dry weight basis. The total dry weight is then carried on to the next section to calculate the energy balance. The only places where significant errors are intro- duced in this section of the program are: In option one of Section 3 the possibility of some error is present with the residue-to-grain ratio, and with how close the entered yield is to the actual yield. If both the residue-to-grain ratio and the entered yield are realistic, then the predicted amount of residue available should be very close to what can actually be removed annually. In option two, where only the grain is being analyzed, the most important input data is the crop yield. The closer this figure is to the actual yield the more realistic the calcu- lated amount of grain will be. In this option it is assumed that all above-ground residue will be returned to the soil. Therefore, as long as there is a sufficient amount of residue being produced at the given yield to satisfy the soil's needs, there will be very little to no error introduced from the soil analysis. In option three, where just a portion of the residue are to be used, the same problems exists that affect option one. In particular when corn cobs are used the "rule of thumb" suggests that there are 4.5 kilograms (9.94 lb) of dry corn cobs per bushel of shelled corn. As in the residue- to-grain ratio, this figure is not failsafe. 35 Determininggthe Net Energy Gain The first step in performing an energy balance is to establish a boundary. The boundary here has been selected to cover all primary energy input to the agricultural system used in the field being analyzed, excluding the sun. There- fore, the energy balance starts with seed-bed preparation, crop planting, chemical applications, harvesting, post-harvest processing and transportation to the edge of the field (Tables 8 and 9). Other aspects included in this section are the increased amount of fertilizers which are applied to replace those nutrients that are removed with the residue (Table 10), loss of residue due to handling and storage, and the bioconversion efficiency (the efficiency of converting the residue to a more useful energy source, such as converting corn to ethanol) (Table 17). The basis on which this section will charge energy costs is dry weight. With corn, for example, where the residue-to-grain ratio is 1.0, half the energy costs should be charged to the grain production and half to the above- ground residue. Whatever amount of residue is being removed, a proportionate amount of energy inputs should be charged to the production. This accounting procedure does not hold true for the energy required to harvest the cr0p component that is being used for alternate use, or the post-harvesting processes. The energy inputs to the harvesting and post- harvest processing should be charged directly to the residue being converted for alternate use. 36 The program allows the charge of energy inputs according to any breakdown desired. 80, if one wishes to charge all energy inputs to the grain production up to the additional nutrients, harvesting and post-harvesting then a zero is entered. Conversely, if all energy inputs are charged to the residue the total energy inputs from Table 8 or 9 would be entered. It is advised to charge the energy inputs to the various crop components on a dry weight basis. The assumptions made in this section by the program are few, and they introduce only minimal error. The assumptions relate to the increased amount of energy applied to the system due to the nutrient removal. It is assumed that the amount of energy is 63500, 11340, and 9070 kJ/kg for the nitrogen, phosphoruszum.potassium, respectively (Myers et al., 1980). The percentage of the residue that the nitrogen, phosphorus and potassium comprises can be obtained from Table 10. The total energy charge to the residue for nutrient removal is minimal. Assuming that the data supplied up to Section 5 is accurate,errors still will be introduced with the energy accounting system, owing to the fact that the data used for energy input are in the form of averages based on the "Michigan Farm Energy Audit" (Myers et al., 1980). Unless a farmer keeps unusually accurate records on total fuel and fertilizers used, however, a better energy input figure will not be easily found. 37 Two other factors that will significantly affect the final output are the amount of field loss from handling, processing, and storage, and the bioconversion efficiency for the particular conversion process. The Transportation System The last section of the program predicts how far the residue can be transported and still maintain a postive net energy yield, as well as the total number of loads it will take to get the crop residue to a bioconversion facility, taking several energy factors into account. First, the net energy for transport is determined. If all the energy was used for tranSport then nothing would be available after conversion. Once the Operator has de- termined the amount of energy available (from harvest of the residue) for transport, the type of fuel and the fuel consumption and the cargo space of the transport vehicle is entered. The bulk density of the crap residue along with the moisture content at the time of transport is also entered. In determining the total distance the residue can be transported the program assumes the empty return trip of the transport vehicle. The problem in this phase of the program is that the energy potential of the transport fuel is compared with that of the alternate fuel being produced at the conversion facility. If ethanol is being produced at the facility 38 and the transport vehicle is operating on that same fuel then there is no problem. However, if, for example, corn cobs are being transported by a diesel rig to a gasifica- tion facility, the comparison becomes complicated. Even though the conversion of diesel fuel to work is accounted for in the fuel consumption and the conversion efficiency (Table 17) of cobs to producer gas has been accounted for, it is not an accurate assumption that the producer gas would perform similarly to the diesel fuel. In current practice energy balance is computed strictly on the heat- ing value of the energy inputs and outputs. To be even more realistic, the quality of the alternate fuel should be accounted for. 39 CHAPTER FOUR SINGLE FIELD SAMPLE RUNS Purpose of Sample Runs In an attempt to demonstrate what factors are used in the program, how certain variants will affect the amount of residue available and how the program is used, two hypothetical fields in Ingham County have been analyzed. In this field analysis of two different soil types, two different craps (corn and wheat), have been used, as well as two different slopes (22 and 62). The input data, explanation of assumptions, and a discussion of the results follow. Input Data for Sample Runs The two fields which were run in the sample are each 32 hectares (80 ac). One of the fields in an 0wosso sandy loam soil. The second field is a Spinks loamy sand soil. The yield for each field is: 7540 kg/ha (120 bu/A) for corn and 2700 kg/ha (40 bu/A) for wheat. There were four runs per field. The first run assumed a slope of 2% and corn as the crap. The second run assumed a 6% slope with corn as the crop. The third and fourth runs assumed slapes of 2% and 6% with the crap being winter wheat. All 40 the other inputs were held constant. The data used in the order it is entered into the program are: (1) the wind erosion analysis (Section 1 of the program); soil erodibility index for field #1 is 86, for field #2, 134; knoll factor, 1; soil roughness factor, 1; climatic factor, 82; field length, 400 meters (1320 ft); wind deviation, 45°; no wind breaks. (2) the water erosion analysis (Section 2 of the program); rainfall factor, 75; soil erodibility factor for field #1 is 0.28,with atolerable soil loss of 6.7 t/ha,for field #2 the sail erodibility factor and tolerable soil loss are 0.17 and 11.1 t/ha respectively; the slope length factor for the 22 slope is 0.46 and 2.5 for the 6% slope; the support practice factor is l. (3) prediction of total crop and residue and the energy potential in the field (Section 3 of the program); expected yields are 7540 kg/ha (120 bu/ac) and 2700 kg/ha (40 bu/ac) for corn and wheat, respectively; residue-to-grain factors are 1.0 and 1.7 for corn and wheat, respectively; moisture content at yield reporting is 15.5 and 14 percent for corn and wheat, respectively. (4) determination of the amount of excess residue available for removal (Section 4 of the program); option 1 (see Chapter 3) was chosen because all available residue is desired. 41 (5) determination of the energy balance (Section 5 of the program); handling losses 50%; bioconversion efficiency, 100% (it is assumed that the residue will be burned in a furnace. This does not indicate that the furnace is 100% efficient, rather than 100% of the heat made available by the burning of the residue is available for the furnace). The energy inputs in crop production for both corn and wheat are porportional to the residue-to-grain ratio. They are 2,500,000 kJ/ha (950,000 btu/ac) and 1,400,000 kJ/ha (540,000 Btu/ac) for corn and wheat. The energy to harvest these residue was (assuming windrowing the residue and baling in small rectangular bales) 1,700,000 kJ/ha (650,000 Btu/ac) and 850,000 kJ/ha (325,000 Btu/ac) for corn and wheat. No post-harvest processing was performed. The nitrogen, phosphorus and potassium factors were 0.0111, 0.0018, and 0.0133 for corn and 0.0067, 0.0007 and 0.0097 for wheat, respectively. (6) the transportation system (Section 6 of the program); it is assumed that 50% of the equivalent energy is wanted for work; the fuel used for transport is diesel; fuel consumption is 2 km/l (5 mpg); hauling capacity of the truck is 68 m3 (2400 ft3); the bulk density of the residue baled is 160 kg/m3 (10 1b/ft3), and the moisture content at harvest is 20% (see Table 11 for list of input data). 42 Results of the Sample Runs Table 12 contains all the results generated for the sample fields in the six sections of the program. In the first two sections the soil loss for wind and water erosion are found for the particular cropping and manage- ment system. The combined losses must be less than the tolerable soil loss for the field in question. One can see that for field #1 it is only when the slope is 2% that the calculated and combined soil loss is less than the tolerable limit. If the cropping rotation was changed and a year or two of meadow was introduced then it is possible that residue would be available from field #1 with a 6% slope. The cropping rotation assumed that only corn and wheat were being produced in the examples. To be within the tolerable soil loss of 6.7 t/ha for field #1, 2800 kg/ha of residue was required to hold wind erosion to 2.2 t/ha. 2200 kg/ha was required to keep water erosion to 4.2 t/ha. Section 3 calculated that the total above-ground matter, grain and residue, for the entire field #1 was 412,800 kg (dry weight basis). Section 4 then subtracts the grain portion and the amount of residue that must re- main for soil maintenance and computes a total of 116,000 kg (dry weight) available. Based on 1.63 x 104 kJ/kg (7000 Btu/lb) the gross energy potential is determined and then all the appropriate energy inputs are subtracted. 43 The result is the net energy available for use and/or for transport. The last section (Section 6), for field #1 with a 2% slope planted in corn determines what the great- est distance is that the residue can be transported and the required number of loads. With 50% of the energy allocated for transport, the maximum distance is 1550 km for each of the seven loads. When compared to the corn grown in field #2 with a 2% slope, one sees that not aetmnfl1residue is available. At first this seemed strange because the soil of field #2 is more susceptible to wind erosion, as can be seen by comparing the soil losses. Field #1, with 2800 kg/ha left in the field, has losses of about 2.2 t/ha, whereas field #2 with 2500 kg/ha of residue left in the field will have losses of about 7.8 t/ha. The reason more residue can be removed from field #2 is because the tolerable soil loss is 11.1 t/ha as compared to 6.7 t/ha for field #1. It is this higher tolerable soil loss limit that allows residue to be removed from field #2 with a 6% slope whereas in field #1, with a 6% slope no residue can be removed due to water erosion. Usage of Results Once a field has been analyzed, as have fields #1 and #2, the results can be applied to a situation where the crop residue is to be used for some purpose other than 44 returning it to the soil. The first step in applying the results is to plan on leaving the residue required to maintain the soil's productive capacity. It must be noted that the amount of residue required for soil maintenance was calculated for a given management system. For the sake of the soil, adherence to the management system is impera- tive. In the case of field #1, in order to keep the water erosion level down to 4.2 t/has the field must be strip tilled with 2200 kg/ha (dry weight) of residue remaining. If the energy balance is positive, as it was in all the sample runs where residue could be removed, one can assume that there will be more energy available than that used in producing the residue. To keep the energy balance positive, the residue cannot be transported farther than determined in Section 6. It is unlikely the residue would be trans- ported further than that, because of the economics in- volved. The economics of the total system are not con- sidered in the program at all. If the results indicate that a system for residue removal and conversion is viable, it cannot be assumed that the economics will create a positive return. When using the results of an area study to plan an energy conversion center one must be careful. A realistic amount of field, handling and storage losses of the residue must be used to determine how much residue the facility will have to process. Knowing the amount of residue available at the site of the conversion center will help in determining the apprOpriate size of the facility. 45 46 CHAPTER FIVE RESULTS AND DISCUSSION OF CROP RESIDUE AVAILABILITY PROGRAM Using the tables and figures contained in this paper, together with the computer program, much of the agricultural land east of the Rockies can be analyzed. The author is aware of no other program that will analyze a single field's potential for alternate energy. Nor is the author aware of any large-scale program that is capable of analyzing both water and wind erosion constraints to residue removal, along with an energy balance of all primary energy inputs including increased fertilization, for the total system. Comparisons With Other Works There are computer programs available that will perform sections of the crop residue availability program presented here. Dr. Bill Larson has a program that es- timated the amount of residue available in the twelve states comprising the North Central section of the United States. Larson's program, however, analyzed only the eastern part of this area for water erosion constraints and only the western section of the area for wind erosion. There is no energy balance or economics involved in his 47 program. The program developed by Larson was intended only to approximate the amount of crop residue available, with future planning and policy-making in mind. It can be seen from the results on the two fields in Ingham County that one cannot assume water erosion is the limiting factor to residue removal for some states or regions and that wind erosion is the limiting factor for others. From Table 12 it is seen that the 0wosso sandy loam was limited in residue removal by water erosion whereas the Spinks loamy sand was limited by wind erosion. With 2200 kg/ha of residue (dry weight) left in each of these fields with a 2% slope the water erosion soil loss was 4.2 t/ha for the 0wosso, whereas on the Spinks the soil loss due to water erosion was only 2.7 t/ha. Wind erosion caused soil loss of 2.1 t/ha and 7.8 t/ha for the 0wosso and Spinks soils, respectively, when 2500 kg/ha of residue (dry weight) was left in the field. Versatility of the Program In an effort to enhance its flexibility, the program was developed so that various sections could be used completely independently. The two most readily usable sections of the program are Sections 1 and 2, the wind erosion equation and the water erosion equation. 48 Wind Erosion Section The wind erosion section is a vast improvement over the manual method first developed by Woodruff and Smith (1965) and the later version now used by the Soil Conser- vation Service for analyzing the soil loss for a particular field. The major improvement over the earlier system is the computerization of a nomograph with a sliding scale. Once the scale has been cut out of the figure, the possi- bility of losing the sliding scale and the probability of poor interpolation creates a much higher potential incidence of error and inconvenience. The improvement over the system now used by the Soil Conservation Service consists primarily of the reduction in the number of tables that are used. The possibility of faulty interpolation is also minimized. Water Erosion Section In the water erosion section there are three elements which improve the use of the USLE. The first is the speed with which a field can be analyzed, and, once run, how rapidly changes in the annual soil loss relative to changes either in the cropping-management or erosion prevention practices can be predicted. This capability is important mostly to a field agent working directly with a farmer. The agent can determine in a matter of seconds what the pre- dicted soil loss will be given that farmer's agricultural practices,and how the loss would change with a change in the agricultural practices. 49 Another improvement over the manual system is the direct computation of the slope length (LS) factor as opposed to obtaining the LS factor from a graph. This accomplishes two things: first, the total time is reduced for determining the various factors that represent the field being analyzed; secondly, the possibility of mis- reading the figure is eliminated. The most significant improvement is the reduction of the number of tables and the probability of faulty interpolation of the various factors and end results. Section 2, compared either to the original manual method developed by Wischmeier and Smith or the system used by the Soil Conservation Service, pro- vides greater accuracy than can be gotten by reading factors off the graphs or taking interpolations from the tables. The Energy Balance Like the two sections that analyze erosion phenomena, Sections 5 and 6 can be used independently of the rest of the program. The two sections can be used for studying the energy balance associated with crops, or portions there- of. Though it is recognized that this section does not have the potentially wide-spread use as does Sections 1 and 2, it will be useful in analyzing community size alcohol stills or other bioconversion facilities that utilize the grain or residue component of a crop. This feature of the 50 program enables the operator to determine whether more premium fuels, such as diesel or LP gas, are being consumed in the production of the crop than the portion of grain or residue being converted to other forms will yield. To perform this analysis one must know how much energy is going into the bioconversion facility, and must have on record how many liters of fuel were used during total crop produc- tion. Limitation of the Program With the crop residue availability program caution must be used in selecting the variables that match the agricultural system being analyzed. At best, the data generated will be only an estimate of actual conditions. Because of this when choosing input data it is advisable to use approximations on the conservative side. Because of the approximations in much of the input data (see Chapters 1 and 3) caution must be used in inter- preting the results of the program. The soil structure should be examined after a year or two and the agricultural practices modified as indicated by the results. If the soil structure is deteriorating, more of the crop residue must remain on the field, with the possible addition of manure; if the soil structure remains the same, or improves, then present practices may continue. 51 CHAPTER SIX SUMMARY AND CONCLUSIONS Summary Where crop residue removal is proposed, the field in question should first be studied to determine the possible ill effects on the soil's productivity from such removal. The premise is that, in terms of commonly accepted principles of soil management, only the residue can be safely removed which is in excess of that required to main- tain adequate soil conservation practices and promote the soil's productivity. It is necessary, therefore, to devise a means of measuring the variables involved in soil main- tenance to determine how much residue can be removed, for any given combination of variables, and whether the result- ing energy balance will be positive or negative. To accomplish the above a computer program was develOped for use on the TI-59 programmable calculator. This program using previously developed wind (Woodruff and Siddoway, 1965) and water (Wischmeier and Smith, 1978) erosion equations and knowledge of the soil's physical characteristics, determines two pieces of information. First, the amount of residue which exists in a field in excess of that required for soil preservation is estimated. 52 Taking into account the current agricultural practices in that field, the second aspect the program addresses is an energy balance. The energy balance portion of the program considers the process from seed-bed preparation through post-harvest processes, and current levels of fertilizer application, and analyzes the transportation system in- volved in moving the residue to a bioconversion center. The final output of the program is the net energy gain (or loss) from residue removal from a given field. Based on the transportation system involved, the distance the residue can be transported and how many loads of residue there will be is also calculated. Economic considerations involved in the total system are not addressed. Conclusions After a review of the literature and an analysis of the sample runs described in this writing it was determined that: 1) Each field proposed for crop residue removal should be considered on a case-by-case basis, analyzing as accurately as possible the conditions of that particular field, and avoiding generalizations; 2) Such a field should be analyzed in terms of the potential increase in wind and water erosion and soil compaction from the removal of residue, and 53 whether the residue to be removed constitutes an excess of that required for proper soil maintenance; 3) This "tool" is the best available means of calculating how much crop residue can be removed. It also gives insight into the energy balance and distance the residue can be transported; 4) Crop residue from some soils and locations can safely be removed. 54 CHAPTER SEVEN RECOMMENDATIONS FOR FURTHER RESEARCH Program DevelOpment The following recommendations are made to increase the ease of operation and the accuracy of the program. In Section 1, the Wind Erosion Section, determining a mathematical relationship for Figure 5 would reduce the inaccuracies introduced when reading the E4 factor. The problem encountered with this nomograph is that the scale is not logarithmic, though it closely resembles a logarith- mic scale. When an approximate logarithmic interpretation of this scale is attempted, the lower end, that is, from an E4 of ten downward, is unacceptable. The error increases as the field size is reduced. It was found that a straight interpolation between the other segments of E4 will be well within allowable tolerances, however, this option is limited by computer space. Either some further curve fit- ting techniques or a large computer should be tried. Figure 6 should also be reduced to a mathematical expression. With three coordinates this figure becomes a relatively uniform surface (see Figure 11). The axes for both the "E" and the "E4" are logarithmic. 55 In Section "2" the Water Erosion Section, com- puterizing the cropping-management (C) factor would greatly increase the resemblance of the model to actual field conditions. The manner in which the C factor is calculated is described in Wischmeier and Smith (1978), owing to limited computer space, this procedure was not incorporated into this program. Another major change in the program that would increase its accuracy relates to the manner in which the energy inputs are charged against that portion of the crap being studied. How this should be accomplished is not clear. A comprehensive and widely accepted method should be developed. Verification of Program A long-term study of residue removal, and the actual effects it has on the soil's condition, is recommended. Actual long-term (10 years or more) data collected on erosion, compaction, and energy inputs into the system as related to residue removal would enable researchers to determine the extent to which the model actually represents the field that is being analyzed. With this information, changes could be made in the various input factors which would be more representative of actual conditions. Also, an indepth study of the affects of residue removal in small 56 increments, say,by 100 kg/ha, rather than by 500 kg/ha would be of interest. If increments this smallmake signi- ficant differences in soil structure, fertility, and soil loss, then methods of determining the amounts of residue which should remain in the field need to be refined. APPENDICES THE EFFECT OF MOISTURE, FERTILITY LEVEL, AND APPENDIX A TABLES TABLE 1 DEGREE OF SOIL COMPACTION 0N CORN PLANT GROWTH 57 Weight of Weight of Topzroot Weight of t0ps roots ratio total plant Treatments (8) (g) (g) (3) Loose, wet, ' fertilized 39.4 14.8 1 0.38 54.2 Loose, wet, unfertilized 23.5 10.1 1 0.43 33.7 Loose, dry, fertilized 27.5 9.3 1 0.34 36.8 Loose, dry unfertilized 20.3 9.3 1 0.46 29.6 Compact, wet, fertilized 16.0 6.5 1 0.40 22.5 Compact, wet, unfertilized 17.0 7.7 1:0.45 24.7 Compact, dry, fertilized 20.1 11.3 1 0.56 31.4 Compact, dry, unfertilized 19.3 9.9 1:0.51 29.2 Source: Bertrand and Kohnke, 1957. 58 TABLE 2 SOIL ERODIBILITY INDEX (I) FOR SOILS WITH DIFFERENT PERCENTAGES OF NONERODIBLE FRACTIONS AS DETERMINED BY STANDARD DRY SIEVINGl Units Percentage of dry soil fractions 0 1 2 3 4 5 6 7 8 9 >0.84 mm tens t/A 0 - 310 250 220 195 180 170 160 150 140 10 134 131 128 125 121 117 113 109 106 102 20 98 95 92 9O 88 86 83 81 79 76 30 74 72 71 69 67 65 63 62 6O 58 4O 56 54 52 51 50 48’ 47 45 43 41 50 38 36 33 31 29 27 25 24 23 22 60 21 20 19 18 17 16 16 15 14 13 70 12 11 10 8 7 6 4 3 3 2 80 2 - - - - - - - - - 1 For a fully crusted soil surface, regardless of soil texture, the erodibility "I" is, on the average, about 1/6 of that shown. Source: Woodruff and Siddoway, 1965. TABLE 3 SOIL ERODIBILITY INDEX (I) 59 Percent of Dry Soil Aggregates Over 0.84 mm Soil Textural Classes Percent Soil Erodibility Index (I) Very fine sand, fine sand, 1 or coarse sand. Loamy very fine sand, loamy fine sand, loam sand, loamy coarse sand, or sapric organic soil materials. 10 Very fine sandy loam, fine sandy loam, sandy loam, or coarse sandy loam 25 Clay, silty clay, non- calcareous clay loam, or silty clay loam with more than 35% clay content. 25 Calcareous loam and silt loam, or calcareous clay loam and silty clay loam. 25 Noncalcareous loam and silt loam with less than 20% clay content, or sandy clay loam, sandy clay, and hemic organic soil materials. 40 Noncalcareous loam and silt loam with more than 20% clay content, or noncalcareous clay loam with less than 35% clay content. 45 Silt, noncalcareous silty clay loam with less than 35% clay content and fibric organic soil material. 50» Soils not suitable for cultivation due to coarse fragments or wetness, wind erosion not a problem. -- 310 134 86 86 86 56 48 38 Source: Soil Conservation Service, 1978. TABLE 4 1 PREVAILING WIND EROSION DIRECTION ’ 2 6O Location Jan. Feb. Mar. Apr. May Jun. Jul. Aug. Sep. Oct. Nov. Dec. Battle Creek,MI 248 248 248 270 247 248 248 270 270 225 225 225 Cadillac,MI 248 248 292 292 225 225 247 225 246 203 203 247 Duluth,MN 292 270 293 90 90 248 270 68 270 248 293 293 F1int,MI 225 270 248 248 247 248 248 225 225 225 225 225 Green Bay,WI 292 228 225 247 225 225 225 225 225 225 270 227 Marquette,MI 0 338 0 0 0 180 202 0 180 180 180 180 Mt. C1emens,MI 225 225 225 203 180 201 202 180 180 202 203 225 Muskegon,MI 248 270 248 225 205 225 225 203 203 203 225 270 Oscoda,MI 338 315 270 239 227 270 202 225 248 224 226 315 Pellston,MI 270 270 270 270 248 248 248 248 248 248. 292 270 Sault St. Marie, MI 292 293 293 293 293 293 293 293 293 293 293 292 South Bend,IN 225 270 90 315 338 338 338 0 180 180 225 225 Toledo,0H 247 247 248 247 247 225 204 225 248 225 220 225 Traverse City,MI 203 202 202 202 203 225 203 203 202 202 180 225 Ypsilanti,MI 248 270 270 270 270 270 270 270 270 248 248 248 1Prevailing wind erosion direction -- direction of winds over 12 mph 1 ft above ground surface. 2 Source: U.S. Soil Conservation Service, 1973. "Direction" means degrees, measured in a clockwise direction from north which is 0°. 61 TABLE 5 MONTHLY CLIMATIC FACTORS "C" FOR EACH COUNTY IN MICHIGAN Monthly Value of "C" County (Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Alcona 7 7 8 7 6 3 3 3 4 S 7 7 Alger 5 4 6 6 2 3 2 2 4 4 S 3 Allegan 7 10 12 9 7 5 4 4 4 5 8 7 Alpena 7 7 8 8 6 4 3 3 5 6 7 7 Antrim 6 7 8 8 7 4 3 3 S S 8 8 Arenac 8 7 8 7 5 3 3 2 4 S 7 7 Baraga S 4 7 S 2 3 3 2 4 S S 3 Barry 7 9 10 7 S 4 3 3 4 5 7 7 Bay 7 7 8 7 S 3 3 '2 4 S 7 7 Benzie 7 8 10 9 8 S 4 3 5 6 9 8 Berrien 7 10 10 9 8 5 4 3 S 5 8 8 Branch 7 8 9 8 5 4 3 2 4 S 7 7 Calhoun 7 8 9 7 S 4 3 2 4 S 7 7 Cass 7 9 9 8 7 4 3 3 5 5 7 7 Charlevoix 6 7 9 9 7 5 3 3 5 S 7 7 Cheboygan 6 7 8 8 6 4 3 3 S S 7 7 Chippewa 6 5 7 7 7 4 3 2 4 S 6 4 Clare 7 7 8 7 S 3 3 2 4 5 7 7 Clinton 6 6 8 7 4 2 2 2 2 3 7 4 Crawford 7 7 8 7 6 4 3 2 4 5 7 7 Delta 7 5 7 7 S 4 2 4 S S 7 5 Dickinson 6 S 7 7 S 4 2 3 5 S 7 S Count Eaton Emmet Gene Glad: Gogel Gran Tra Grat Hill Houg Hurc Ing] Ion Ios Iro Isa Jag Ka] Kaj Ker Kex La] La} LE( TABLE 5 .. - (Cont'd.) _62 Monthly Value of "C" County Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Eaton 6 8 9 7 5 3 3 2 3 4 7 7 Emmet 6 7 8 9 7 S 3 3 5 5 7 7 Genesee 7 7 8 7 4 3 2 2 3 5 7 7 Gladwin 7 7 8 7 S 3 3 2 4 S 7 7 Gogebic 5 5 8 9 6 4 5 4 5 8 9 5 Grand Traverse 7 7 8 8 7 5 3 2 4 5 7 7 Gratiot 6 7 8 7 5 3 2 2 2 4 7 6 Hillsdale 7 8 9 8 S 4 3 2 4 S 7 7 Houghton 5 4 7 5 2 3 2 3 5 6 6 3 Huron 8 7 8 8 5 3 3 2 5 5 8 7 Ingham 6 8 8 7 S 3 3 2 2 4 7 7 Ionia 6 7 8 8 S 3 2 2 3 3 7 7 Iosco 7 7 8 7 5 3 3 2 S 7 7 Iron 5 5 7 7 6 4 3 3 S 7 8 4 Isabella 7 7 8 7 5 3 3 2 3 S 7 7 Jackson 7 8 9 7 S 4 3 2 4 S 7 7 Kalamazoo 7 8 9 8 6 4 3 3 4 5 7 7 Kalkaska 7 7 8 7 6 4 3 2 4 S 7 7 Kent 7 8 10 10 6 4 3 3 4 4 7 7 Keweenaw S 4 7 5 3 3 2 3 S 6 5 3 Lake 7 8 10 7 6 5 3 3 4 S 7 7 Lapeer 8 7 8 7 S 3 3 2 4 S 7 7 Leelanau 7 8 10 9 8 S 4 3 S 6 10 9 TABLE 5 -- (Cont'd.) ~63 Monthly Value of "C" County Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Lenawee 8 9 10 7 5 4 3 2 4 5 8 7 Livingston 7 7 8 7 S 3 3 2 3 4 7 7 Luce S S 6 7 4 3 2 4 5 5 5 Mackinac 6 6 7 8 6 4 3 2 4 S 5 6 Macomb 10 10 10 10 6 5 4 3 5 6 10 10 Manistee 7 8 10 8 8 5 4 3 S 6 8 8 Marquette 4 4 6 S 2 3 Z 2 4 4 S 3 Mason 7 9 12 8 8 5 4 5 6 8 7 Mecosta 7 7 9 7 5 4 3 2 4 S 7 7 Menominee 7 6 8 9 7 5 4 3 6 8 9 8 Midland 7 7 8 7 5 3 3 2 4 5 7 7 Missaukee 7 7 8 7 S 4 3 2 4 5 7 7 Monroe 10 10 10. 9 S 4 3 3 4 S 8 7 Montcalm 7 7 8 7 S 3 3 2 3 4 7 6 Montmorency 7 7 8 7 6 4 3 3 5 6 7 7 Muskegon 8 10 12 12 6 S 3 S 4 5 8 7 Newaygo 7 8 10 8 6 S 3 3 4 S 7 7 Oakland 9 7 10 7 S 4 3 2 4 S 8 9 Oceana 8 10 12 12 7 S 3 S 5 S 8 7 Ogemaw 7 7 8 7 5 3 3 2 4 S 7 7 Ontonagon S 4 8 7 6 4 4 3 5 8 7 4 Osceola 7 7 8 7 S 4 3 3 4 5 7 7 Oscoda 7 7 8 7 6 4 3 2 4 5 7 7 \L Count Otseg Ottaw Presq Rosco Sagin St. C St. J Sanil Schoc Shian Tuscc Van Wash: Waynu Wexf. Sour TABLE 5 (Cont'd.) 64 Monthly Value of "C" County Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Otsego 6 7 8 7 6 4 3 3 S 5 7 7 Ottawa 7 10 12 12 7 S 3 S 4 5 8 7 Presque Isle 6 7 8 8 6 4 3 3 S 6 7 7 Roscommon 7 7 8 7 5 3 3 2 4 S 7 7 Saginaw 7 7 8 7 S 3 2 2 3 S 7 6 St. Clair 10 10 10 10 S 4 3 3 5 6 10 10 St. Joseph 7 8 9 8 6 4 3 3 4 5 7 7 Sanilac 8 9 9 8 S 3 3 2 5 S 8 7 Schoolcraft 6 S 6 7 5 4 3 3 4 4 6 4 Shiawassee 7 7 8 7 4 2 2 2 2 3 7 4 Tuscola 7 7 8 7 S 3 3 2 4 S 7 6 Van Buren 7 10 10 9 7 5 4 3 5 S 8 8 Washtenaw 7 8 10 7 S 4 3 2 4 5 7 7 Wayne 9 8 10 10 6 4 3 3 5 S 8 9 Wexford 7 7 8 7 5 S 3 2 4 5 7 7 Source: SCS, 1978. <‘———mz—zH—A— :m~2Av.— ezuom coaua>uunnoo anon .m.= .3ovooalx .uo>ou young: and: sauna masseuse .eouu swan» anaemic .eouu hoe-mm we on oono adage and: shoe we so can .ouououonh .soxou on unsure Avonnosmv euou away» we canoe some sun: «Janus we on A we and: sauna unsu masons .oseaoou auoo "NUNDOm .oaouuou .ooosvoue mauuaelou torso .uon he acuuuu :o: unsouoawlleouo a no cumsunoso and he Heaven :0: unmouoculueouu m we unmstoso nunNIeN no Heaven :0: ouoouoculumnmsoasuucoo each» one usooohoe sense .osemeH cuou we on uno~m>wsco mm mceooxom can .meouu so: .:mmuw Hanan scum snowmen mo canon mac n N oomwusm “MOm on» we once so «oo no mosewmou o>mo~ noes: mEoumxm ommnnwu mononucen .mn~ N .wcwuceae poems oumwuzm meow use mo oboe no ”em :0 mosewmoe o>eo~ sows: mEoumxm mundane moeanocm .mewucmue nouwa 22:20 .QH ene. nNe. 22:0: .na nNe. ewe. 2:20: .Nn e~9. nne. :20: .- one. 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IIIIIIIII H.HH I IIIIIIIIIIIIIII .. IIIIIIIIIIIII a.e e H.H e.e n.e m.eH m.eH e.e m.eH e.e Hee\eem+< ~.N N.N e.m e.e _+ IIIIIIIIIIIIIII I IIIIIIIIIIIII ~.N Hee\eem comm eeHH some seem eee eee seem seem Hee\mxe> + ............... -; IIIIIIIII eH +. IIIIIIIIIIIIIII .. IIIIIIIIIIIII m.m em + IIIIIIIIIIIIIIII .. IIIIIIIII eeH I. IIIIIIIIIIIIIII .. ............. m.He .mm + IIIIIIIIIIIIIIII .. ......... Ne.eH I IIIIIIIIIIIIIII I, IIIIIIIIIIIII ee.e mm + IIIIIIIIIIIIIIII e--- ------ eeH I. --------------- .1 ------------- ee me we wN wm- wm we wN we wN eHeeHee> Home: snow Home: :900 N .62 eHoHe H .62 eHeHe mHm>AP_I=D<¥CUQ \ Q vv\@ ‘ n A \ H u \ \ . Iv Ixo\M\\. . e \v A. \ w \ \AT \ \ n \ I \\\_\ \ m \ .H V- N - \ u .. x“ .\\V . \ x e \\. \ x . \ \ A. A .\ \ m \ \ A. “\.\-\ m \.\\ A ‘ \ \\ x A... \ I. \ \ \ \- \ A... \ \ \ .x\x \ \n‘ \\ \ \ \.\\\ m eta-85m 36m A. \ 03:0... 3 .20... £3.33 xx; \ \ \ \ 3.3.... on...» .o cot-n 3.3.3.. of. -N 3.3:... 2:. use... on. ow. om. oo. om. oo. <3 I’\ 'XOHddV ISHIE ° H 30 X ‘HOIOVE LIITIHIOOHH 1108 O oH. oN. On. on. On. eo. oh. .erH .eoHEm eon noHoeeooez “momeom Hwom Hmouom ecu wcficHEumuoe HON eosuszI.o mmoon .z... I A 23:28 .. 3:28.... .H 233.: .B.~ .a .3 I: .3. :5. 8...»! :3 A A8 9.3.391 .3333: 8: '33 I» .3553 v3.8. :83! 32.28... l I O a I a :5 a. £223.:- 2.- .E3ul: .3qu 9:30... a AI 0 ~32 3 2.3 u «.23 2. 23:39.0! 3...! 3 '8qu 3.- :2 a. 3.3 A3... .33 3:32...- 5; .g pr I IILI>>I> IIIPIII .I-L -------- p»:- --L- - {IL - 30.1.- I- -1- -------- .II. :- “““‘ ‘N .““ ‘I‘“““‘ “““ E“ ‘C d 1‘ d ‘ V Av v A .vo I I} A Av n A A. I A A I / A A. d_/ I A 2 Al I . I AV 1' Au n.:/. z A A1 I 0 Do A .. o~ , / 25.5 «.0. e . A i d- J A Av A A" z 1 024m hzwommm .. Av Av l' III Av Av Av Av Av Av A A I A. A. e v Av Av Av Av 1'- 1 A a . Av Av Av Av Av III! A Av A Av A. Av Av Av Av: 11! Av Av A Av Av Av Av AV e A Av A A A Av A 1' 1 A. A Av A Av A Av A A A .v A A Av Av A 1.! A Av Av Av . Av A v A A t A Av v Av Av A 1‘ A Av A A A A A Av A A A Av A Av A A A .11 A Av A A Av Av I Av Av Av Avl .v \ A A ooa om ow on oo on on on ONVS HNIJ ABBA + 1118 lNHOHHd 9O Approximate sur- face representing ~ § 223.228823‘“: FIGURE 11.--Three-dimensional view of Figure 6. APPENDIX C CROP RESIDUE AVAILABILITY PROGRAM 91 This part of the total program contains Section 1, the wind erosion section. listings are listed below. The Operating instructions and program Comment Load Press Print 1. Initial Run a. Repartition computer 5 2nd op 17 -- b. Load cards 1 and 2, all four sides 2. Section 1 (Wind Erosion) -- A Key -- a. Soil erodibility index ”I", Tables 2 or 3 "I" R/S "I" b. Knoll factor "Is", Figure 1 "Is" R/S "Is” c. Soil roughness factor "K”, Figure 2 "K" R/S "K" d. Climatic factor "C" in decimal form Table 5 or Figure 3. "C" R/S "C" e. Field length Length R/S Length f. Wind deviation (in Degrees) from Field length Table 4 Deviation R/S Deviation g. Wind Break height Height R/S Height The calculator then computes and prints "E2," "53," and ”£21." __ __ E2 -- -- E3 -- -- E2' These numbers are used with Figure 5 to determine E4. With E4,"T" loss, Table 13 or 14) and Figure 6, the vegetative cover is determined. With Figure 7 and 8 the actual amount of crop residue required in the field is determined. (tolerable soil L '! . -- 3‘3. ::-._: *‘nf: "9|. ‘4': --, ‘-' z ' 8- .. -‘ Listing Sample Print Out (English Units) I Is K C Dist. Ft. Dev. Degrees Breaker Height E2 B3 E2' of Subroutines and Program Sections ¢_ ‘ .I |-...o J'l IA l 1;)"; -O I.” "to soc—L p o-' no I I'lzll ..... 44.1"“: .. . wwfi -' - .1 '°.' F. 'r ' L! -: "‘r .1. ' L. i . -. .3, .; a _o .-' ! .:': b;- i - "In. if} magentu; LL- .. “‘31 (3:! h“; ~[LL [- .0... HMJFOP*MHW ‘." w- {91 r.) -gmp .- '.. _ II I!.. - In [0" '-. -' ' "" I" i f? "1 .... . III .... .. I .1! .' n I “gun!- I”... [3;] infill .....|. 5.“. .._., F'" F“ | I F“ '..... lljv Iflflfifi "3 713 u ""1 l. l'. . I 6:1“: “I 'Hnrnt«can- iigmg '13 c -rl ‘,.~..b ha. ....| y... 3.4 p-A- t-‘— r--‘- if: I IT! LI! l_2| U] L 4‘: r r 't Ij’ T; I ' .L L' o o " f- - I :-' I L... 92 93 Computer Program Wind Erosion Data Stored in Memory Data 51031.. Memorx 3’ ii? Data stored in locations 03 to 5; £3; 17 house the intercept and slope .!_?LW;§ gag for line segment. Dn the left paugcpq-;y§;353 5:. Slde are data for field distances “'TI;.§ T fifiéi ii: of 10 to 60 feet; the right side ‘Z'ff:f:;:_ -3333: $33 of the decimal stores the inter- ,_“3?T:;:fiffjf1 idg cept and slope of line segments l.“5tdi.h3flfii*$ U: for field distances of 61 to 500 23493.34El? 03 2?430.36213 0? 3 Cl 3 E: T , 3313:1233 _; {I 33355.4013? ii 35349.4316? 12 3?343.45l$4 13 40315.4?133 24 41352.4?11 i5 43239.51003 16 46354.530?6 l? _ tiEEL 2231351 15 Data stored in locations 18 to 32 lifiSFEu 31i395! 19 house the intercepts and slopes 3313135. 334094 730 for the line segments for 133159.23'3136? :51 distances 501 to 1500 feet on 13:31:39. 45132? 3;}: the left side of the decimal and 130121 430123 2:}: for distances of 1501 to 5000 'SIZIFIB. 5 24 feet on the right side. 450?3.51 25 49049.53 25 C“! :0"? J -..'= i‘ 53013.54 3 55004.55 9 56000.56 0 5?000.5? 1 57000.57 3 91. Computer Program (Cont'd) Subroutines Steps Code Operation :jflfil T5. ;E&_ Subroutine SUM locates 2301 44 :38?! memory location for 13L-‘ SE; +~ distances 10 to 500 feet HQ? fl: 1 032 53 3 065 25 = 006 59 ZHT WM? 9 + 659 6 1 009 9 = Ijiil S + 011 0 2 012 2 = FMEWMJHWIUNMLHHLH 013 5 ’HT D 1 4 E: + 015 0 l 016 9 = Li? 2 RIM 013 F5 LEL . 1315' 523 { Subroutine C determines the :72?! RF} . upper and lower segment numbers {BET fig: 2 to be interpolated between 322 as = I33 35 + 024 01 1 025 95 = 026 65 K 02? 01 1 023 DD 0 029 95 = 030 42 STD 031 35 36 032 35 + 033 02' 3 D34 00 0 L35 95 : 036 42 3T0 D3? 3? 37 033 93 2TH 95 Comppter Program (Cont'd.) Subroutines (Cont'd.) Steps Code Operation C339 TE- LEW. Subroutine l/X obtains CNN} :35 1’}: the intercept of the line [H11 ?2: HERE segment for distances 10 to 23%;: 31 U} 60 and 501 to 1500 H43 H? INT 6:43, £19: + 045 01 1 34h 33 D 04? DU 0 1:1 -', E! 2:! 1:1 1:] 049 95 = 050 59 EMT 051 55 + 052 01 1 053 00 0 054 95 = 055 92 2TH Subroutine CE determines the 056- 236 LSL ijfi? ;34 I35 intercept fOr distances 61 to flfifi; 7:2; 91-:‘31‘3' 500 and 1501 CO 5000 059 01 01 fléfi 23 IN“ 53* INT _I I: I I'T'. ILT'I '1' Ln 4:. {-0.3 ['03 0-“5 I“ r-o-L ’:.:' I I If!- ya- I'_l'| . :Jl ....'.... I I 'I IT'I '1'. 3.3 I I (fl I -t- 9 DE? 59 INT 063 55 + 069 01 1 UFO DD 0 'ZI?1 as = 022 92 RYH Steps {7“9 '3! ID! ”3.1 C“ L.” 4:.- [J] r-,_'| r-«u |___| I I I I_I I"II u) I _ - .- .- n 1:” .LI I.” up nu -:'_I '._[_I I.“ nu 0.1”; I_ J '3'. IL” 4:" UL.) ['03 H I :I l:l tfl | ' .LI 0:! "- "I I: :w' :I In.) Ina I r-I-I-uI-v-AI 1DEI 1E“; 1J35 1 I] E. 10}7 1 I] :3: 105' I-:5 i 1 L' ‘5 1 ‘2 a .I. .'. ‘. i "J i. i I.- e 4. "I 1, _' ." 'I 1 .1 A A. f 1 It ‘I 1 I»: a J ‘.' Code I "J ("I’ll ”NJ I Ina [.3 IN] IT. I_l' .‘£| " 5'.- I'ZI ._| K- 9 a) i ULI UCI ‘95 ‘2' "2' £— f.— E- '. LI I.“ '.1:| I'_ [‘0 V.” .J ...... '1'- I .] Np“ acntnn £1) I-«s I'_._'.I I'__ I] III I: I II) D-4 I '95 9-: c? 0'... Itnh n13 nann- 0.£I LL IT" '1...‘ .t.‘ 4:; ...l.) "5] lj’u ”"J . ["3 I'.._'I H IF‘ I ['1 .I ’4 'I-I IF. j ..3 ‘1. ”‘31 Subroutines (Cont'd.) 96 Computer Program (Cont'd.) Operation 1 ['1 LL)!— LILa FWTi u} 110$ ~r~ ~1- 1H: 1 b L! 0 .... ..-. ..... II II IO-"* II' I 1 I?! 114T 9114 I"! G'r‘ «In car- -s EVIR 33T[] 41 FVFH r303 r*r* cgornrr ...-4 [I] tr] :0 I'_I'_I I I ‘ -4 4:. up ‘— Subroutine LNX determines the slope of the line for distances 61 to 500 and 1501 to 5000 Subroutine Yx determines the slope of the line for distances 10 to 60 and 501 to 1500 Subroutine GTO interpolates the slope of the desired line segment. Subroutine RCL interpolates the intercept of the desired line segment. 97 Computer Program (Cont'd.) Subroutines (Cont'd.) Steps Code Operation 3? 2 176 110L. Subroutine > in conjunction with sub- : 13 S;- ; routine SUM locates the memory 33:; :35 + locations for distances 501 to 5000 12*} :3: feet- 121 053 5 1223 ‘25 = 12.3: —2 ‘._. 12%— 01 01 135 92 3T0 EI . 22%. Subroutine X2 performs the actual fl ':63 interpolation. ..|I:.. I'J] I'_I_:I "‘-.j "I'I I'I'I I'.) ILD] IT. :37." . . .... i I I 2 t C ‘1 "2' .L I’— 12a ¢ IL. 5 1 '2' '2' I" .L .__ I_I I .- 1'?Q - EH"! 1 :_-_ _.' I E‘ ‘-'i_. 'Q --| s- "l I ‘—l {'1 i 2:: z_1 .3 -I .3 3:. 46+ T: - i -_'I ; I ~_' 4 3' ."‘ r- ” l ixfid 4;: 2L1. 'l -'I -"I '.i ' -'I " 1 .z- ._'_I ._'_I E?! ._:l E! 1 -"’I .‘5 C .4 i I"? -..‘ “K ~": I: c: Lt; -~_ ._‘.: ._I ._I ._I . 0‘. .- ;-- 1.... ’.3 .13. 1:: -:_1 ;_ I; ‘7? IWH I7 ..-. , ._. ._. "I l‘! .‘° C ._'_: ::I 2:! ._l -'_;I 1:. E' --_I -.' ._I .. ..-- Coll "'51 I'_I_'I .13.. I'_ June 30 "I :1". {I I'.) 1:. qur° ...” "L'- '2...) FL) ....I. I ' 5.71 '1...) 412. o- u .- "" *2] I21. I “ 42;. I -. .I -+- “1:! Inl‘l Ll |_I~| I__I| .7". -or“ I... 1 tuu0¢xu - .....A. .....II lm‘ .....I. ...—5 .....I. ...—I- )...L 5...; .....b ...—5 ...-J- I...4 |....I. l"...- .....I. 'I I: i‘! -. I I L.” .1; ..rJL .[la .L .111; «r;- -L} 4:; ..LL 4?... I; I“! I: -I 1:- T l I ‘—= - in E". l I 9 8 Computer Program (Cont'd.) Subroutines (Cont'd.) Steps Code Operation l T L Subroutine EE changes the sign for the intercepts of various line segments. n, l- ._n ‘-.Z= IF." I -J In I i"? m '3 J ". .L .— 5-. A. " ~". I .5 z ." '1 -' - - i, L: .'. ._: 1-! j 3 f—'. as 4 —- — .- " - .- '- “I' : :3? 4mi : E3 1 I: ‘ 3‘: E": .3. 5'! i ._I . “T I_l "T :-l 1' L: :'I .‘. ‘__l El I' j _: ._3 ::I 3., _I ‘. !__. i.— '153 .30 '?Q .5. .-.: -.- ._: -5 ._I _.' i " :‘l :- -'- -' _-:_ §;.-§_I j." 1+ - -' '! ." ‘. .". "I 'T T“. 20; 2;. 3:21 I 4,;- :-:'-,I -:‘—I a '_ L- - - - - i .-‘ --I A! '__l :x ' ' i 5:: ._.I -" ._I _ __ -. .-' .4. '"I l-| I I"I 5 3:: “fi- .:_' 2:! ._‘I 2:! ‘é ; LT. =3 .-‘! ..=- _ .i. :__I ._: _.' *7 : a. .-' .-' .1 -"I I- T. 22:: 2;. :s= 1' .~' ‘7' "_'I {:0 ":l 1:: _ {:1 5' ._: ;_I ._: I_I -; - c: {I i. .5. T H i - 1-’ - I'— ‘I‘-. i S‘- . 4%,; Vs; g g; Subroutine V 2 rounds off the data .. ‘..‘ .' . .- h.- ‘o— ‘—- .7-4 7!: r*! generated. ‘ _1 ._I -' ." : : a q ; I.” '—l I"’ I'- _ f' 34 ~_‘ 4'. 7‘ E. f "P 3": 5;! L.- ... i L. _.. ___! ..- 1 ”T"; L‘ =:' T i 5 ._: ._iI_I I ; ,' 4. ‘?.-'L .4. I”. T um .i. ‘ 'T "7' '- i. i 1 .i.‘ 1‘ ‘7‘ F.‘ ~"I C' “.1 C i 5‘ ._i ...l ._i ._I ._i :24 :2 r: 4 : '_' ‘_‘ I.— '__ '_. i-P'T‘ ‘_l‘-l Ytl!’ : .‘ ‘ I.‘ .' . 1'1 :I J. I . _.I_. a . l ". _.‘ I'I LT ‘-l 3" r" i E' C' -J ..C. C. C 4 '7‘ :-l "I "I 1' l J! 9 g ,- “I .- .- ; ' :I b 3 .‘ 1.. I.— A I a 1 .6] CI I C‘ T ' ° 4 l.‘_. . {I l ' 1 3. CLI 1 ...-1 .. ... . II .. Step 'I |'-._'; [33 {a} [33 ("._I [33 [‘._'_I ['I) ("._I [3) f'._'I ['Ij l"._'I {'._‘I (“._I (“.3 f3) |".;I ['._'I [3.1 ['33 ['33 I»; I» I—mt I"... I-«u- M Ima- I~I- I--* I--* I-- I.» I» I» P-‘o I-4- I--~ I-~4 P. -’ 1"." Pt." I'- l l‘4 S n - r_I :IZ; :2...) .r-.'- IIIIIIIIIIIIIIIIII .. I I-5 III - II .‘ I I 1 I I :l u _ 13 '1'" I In» I""I 0. I ELI I.“ '.Ll I.“ hf} afin nu LLI I.“ .12, IZI .n 4; to r'-.' :T'I I I'_'I ~-.j I o- u. __I 5.0 I_ o— ..I ll” 41'. I'_I_‘I [3) I—--- I l ! I_: _..‘ - i it": 1‘17 :_I . ""I I: 'I Ind III I. 13 CC} III 44 "J." l"- ;T'I I *-.J I ;-.I;‘ (“._:l {1:1 [2" [3.] .....I. F-M- ...; .....L ..."; .....I. .....L ...; .-.; .....I. I .' I» I__. nfl I.I_. 'J‘, .4... I'_._) f“. Code .1 LL. .4: ...—i -. '_l'} LLI r-«t I-- I3". IL- -. 1;. I}. 'LII—-I ..‘1 U ._I. .4; I— I “I! '43 '-.:I 'Jl v.4 m an - ..u I. - :f'I I'I.! 0.13 I-~ I '.LI '._Ll I'_._:I 41.. I.“ I.“ '.L| I [1:3 .....I. --F'4 ['0 Ln 1i!1~£'~£|w4 an 'I I'__l‘| "-.J '43 I'_-_;I nil hi) I'_"] u... — :l I _:I Ir-l- I'I'I I'l :r'I I II V. '._LI tfiI I '.Ll pad- I' 1J1 4;. ._CII C.- _ ._I .4 -"‘I W; U H 't' .-I '_;_'I I'_._) .41.. I 4.. ,..-.. r.) I'_fl F.) [3) [1.) I .— -I l "I I-) I 9 Operation I E'i Luz. i E—I .‘I- ."".. ._I I IT FF. :—.I ‘1" ."I.'"I'T rn.s 'l- i '1'." ['J .. 'I"“" - 'U I“ ll "7.1 «I I_I'I I_I"_I ......I Is. :3 ‘U 20 ' ....1 I_II .. I- . -. I . I L’ .—l O O - r- r- _L..' IL... T : I'. i -_ I: L- J _ .... fl ‘9 'TJ 3'43 ll 3U :-=: :3 -~ -«| I_I"I -_—_. --l l --'l .-.I II... I.' 7. '..' :- ._I ._I ITO } T ."I '1 l -. r' 7:551 r- '. I -' I"! I.| J ID .. ....- a- Computer Program (Cont'd.) 99 This section of the program is where all the input data are loaded. calculated field length equivalent is determined. Also, the Steps m m m m I"-." m In) In) M m m In: m l"-." m m m 1"." ru m M In." ..r.:.. 4;. ..lii 41:. 4:. 41:. 4'2. 41:. 41:. -12.. IL.) ILeLI I'_._'I I'_._’I I'.'I I'.’I I' I. .. c -.1 an .311 .1... (,1 In} I”; I ._‘I I'_.‘I I:_I'I I'.'I l". ... - ... '._LI III .... O . '. I ...—b I ‘ 1 414 'I.-.'I I I'T‘. I' I n ...' ‘-.I- ....J I. _1_I I'_'I:I ‘ Code _I I 4:. I'_._) I_ "'--J [III I. 1 [._I [2| I'_._‘I ['Ij (:1 III '4.” :0 3". ;....~ «III; Pd" I Int '“-.J I-- I ”._:I (3 I2] {I} l:l Ij“. I'I“I I‘T'. "-.j III ..[41 I' J I I_I’I I->‘- ....J M ‘2'". "a. I... \ 100 Computer Program (Cont'd.) Operation Depending on the calculated field length, this section takes the program to the location needed for interpolating for the line segment associated with the {:1 I:l I'J] -._.- I T I"I 'I i 9y} distance. 3'! ’- I—I - C"! I: m -:: If] I I 112' “I [I] f r.- I... .... .... I . . - I .... ..r‘ vIII.I .... - .3 T [1 :I I ;_I 101 Computer Program (Cont'd.) This section will compute the intercept and slope for line segments associated with distances of 10 to 60 feet. 350 ?5 ;£% 355 flé E: 351 1? 3' 235 J? 9 353 43 951 23? 32 HIT 353 33 33 333 43 REL 354 T1 3&9 339 33 33 355 44 SUN £90 7? CE 256 42 iffl 291 ii f' 35? 01 01 ESE ?1 SEE 353 ?S 293 52 EE 359 DE 2 294 ?6 LSL 250 as = 2?? 16 H' 341 21 332 296 43 REL 352 53 C P9? 3? 3? 263 43 QCL 293 ?1 SEE 264 3? 3? 299 44 SUM 355 21 332 390 ‘2 STD 355 44 gum 331 ul 01 222 42 STD 302 71 SB? 353 81 01 383 45 TX 269 F1 SSE 304 42 STD 320 35 1=g 305 33 33 3?: 42 STE 336 23 REL 2?2 33 33 30? 35 35 2?3 %3 REL 303 F1 389 2?4 35 35 30? 44 SUN 222 44 sum 311 01 01 2?3 01 01 3:3 45 I” 3?? ?1 388 314 42 STD £30 35 142 315 3? 39 331 43 ETD 316 ?1 SEE 333 39 3? 31? 61 BTU 333 $1 339 3:3 61 ETD 284 43 38L 319 15 E 102 Computer Program (Cont'd.) ted with distances of 61 to 500 feet. This section will compute the intercept and slope for the line segment assoc1a .....- -..... ...... CL ...»... I-._ I._ 7-. PH Mn mu 1.. F um nu .....H. -L ...u. on M n... 1.. .... H'..' T D :39 . ...... .. .. ... ....T . ...... ....... ..vu ...... Du ...: Du ...L. ..I-. ....... B H. T... ..l... hr... HM T- ....... ........ “...... DU ..H. T. .H... Du - m»... T... _r.r. . .... Du T... ...: -.L .....u .5... w... ....... ...... 1L .2... DH ....... ....... .....H. ...... -L .....d. ....... J .H... .I I. 'I o L. ....4, ...; 3.... ...... .....- .3. 1.... ....._ ...H. m... as... «...- 1... 44. ..:... 4.... 1... .... ...; OH. ..:... ...—H. 1... Au- .w..._ 4.... ...i ......... ...... Q... 1... ..-. 1.... C . - .- .m. .s- ... ..- nm...- .2- .s._uu ..- n,. .e._uJ. a.__uu ..- -e. .s..uu ..- m.. .»._uh...- .a. :m. 1. 1.- 3.... ......_ ...”- a.-. .1.... 4:... "‘ c... ._n. 7.. .,...H... ...? .HH. ,1... ..:... ....... d; c... ..h. a..- .H. .u... .H. 1.. ......_ .....H. i- ...... ...n. T: 0.... .u... .H... ...... ...; ....... .4. .c..... ...... ...... .....H. .... . 2.... 5-... :4. .._..__ ...-.. ...... ...n. ...»... ..h. ....H. ..h. ..h. ..h. ..h. ...»... .3.-. _. ...... .1. 7-. T: ...... q. ...- 7- .H. .H. 3 o... o... 3 ........ .H......_ 0.. 'l .' -II -' '- -‘I "l -- " -- 'l I- -l -. -' ‘- " II. -I -. I- -- "I " '- I- -' -- '- " -- 1|. .It ..........._.................—................._....._.........................._..—_...._.............._ v A. c. .. .. II .0 .. .u in o. I'Oa o. co 0. .o I. on 4' .0 n. I: II 9. II I. u. A. I. v. o. .0 on o. ...... : .... H. m...” m - .... E 2.. ...- P.” H D 1 p... n... 0.... L ...“. H. m... D 1 P. D a. p... ..-. E ...: .....M ...... --.. T- .... _ ...... __ ...... ...... ...... o... ...... T ...... ...... E T- ...... C 3 -.. H. T .H. R. E T- ...... B ...... ..._ 5.... ...... .-.. ...... ...... Dr... C... .H._... ....... fl... ..:... C... D...” ....... ......_ C... C... an“. ........ ....... ......“ ... a,. n.. .5. .-. ..- n,. --. :4. a,. c». .-. an_.qn_ a,- ... .s..ue .-. .-. ... m,. mm..ms_..u .-. .2- a,. ... ... .q. n.. n.. .-. ... . .. .. ...... fi... .4... 1g: .H. 7 .HH. ...4... ..:. 5n... ....n... ......,_ «.... J: 4.”... ..-... «..: .w..._ an... .H....._ 4n... ........ _...... A”... ......2 .H. 7.. .....u ..“H. ........_ ...... C... .1 l - .“ ....-. ......— E .. ..h. T... On. ....fi. .H.... 1... ......u 3...... ..m... 5.... ...—H. _...... O... Q... flu. ...... _....._ fix”. .4: C... ..h. 7.. .....H. O... .HU ...... ......_ ...... 4.“; .....w,. n,. .u...... m.. .u...... m,. n.. .4...qn_ a.. _uJ..uJ__qa..wn_.qn_.qn_..n. ..- ..- .s- ..w. ..- .n.. A». .e. .n.. ... =-. c-. e.. =-. 2-. _H..I.— ”1.... .l.l. «I.-.- . ..... .l. ..... ..... .-.... ..:... .U..... ...... ...... ..:... ...... ..:... ......... .....H. ...... .4... ....... ........ ....... ..... m... .-.... .1-. .-.-. .-.-. ...-. ...-. .-.-. .-.-. .-.-. .-.-. ...-. .-.-. _-_-. 103 Computer Program (Cont'd.) Steps 386 to 400 determine whether the program should go to step 401 or Section D' which is dependent on the distance. Steps 401 through 458 calculate the intercept and slope for the desired line segment associated with distances 501 to 1500 feet. .H. .L ..h. on .....H. _ . “.... .... a; ..:... ..:... ...— .r -..... L c '- . r... _... .fi. ....... B ....T ....... .. ..... ....... ..i ..... 1.... .I.... a... l .. . . ..l. . — c c A . _ c .. 1 1 II J“. 4.7.1.7 T... ...... :1... ..:J ...... 4.... .w; .wfl. H.” DH. D"... ”1... D -..... E... .. .. hr... .... _. ..... .mm. .....H. .5... ...... ....... H . 1.1 ..7; ...... ........ 4]... III. I1. '- ......_W.H....__ :. d- :4. .u... .....c. Q... .... .u .. .... u- o _ ...... ...._ ..._. ..... 1,... Jud—... :4. ..: ... .25.. .. .... ... .. .4. CW. ...—.... .... I: II ........_ .. ... .4. .4...4. +-- ... mu. u“- ...... ..:}. ..H. HM mmnm .1 .w..._ my... ..H... ......_ ...... ......._ ...—n. _...... ..H. .U... .U... mun... DJ). ..:... ....o.. mm. mm. no.2.q. ._y q ........ ....-. 4%. d. .....H. T: .H. 4.... 'l ..:... J2... Q... .1-. .HH. .4..% mm ..:... a...“ ....d... .1.... 4 nu T: .. J .1... ...—H. .. ...”...h In. ax—z .L L «.... Pk .w..... as _ -- ...._ _,... Mrs. .s 47 a: 1+. ... HEMP... DH. 1.. E C... C... 3...”. 1|. .flu—z 41.5 T; E .m...... . 1.5.. i... . ... an“: .L .1. EL 9... ..h. ...l...._ .....H. a; .1.... .J-n 4,». :4. .9... .H. mm. .H. .4..+ 3: ..q .L ....... DH. .. .....H. ....... . . ”H: S H ....H. mi 4.. 11 c». P... . c-.. ...r... . 4;: A“: Jr .4. P... Du C... .1.... Ti . . to: . . . _ _ _ 1 .al. . .onH—u. Au: 7- A». ...-H. Mi, m"... .l.-. ...»... .. ...._.._ ....... AMT ...; 5r 7; .u... ...ll.. ..:. mm.e ...... OH. 4...... d- :J. ...5._ ...... ..:... ..:..._ . .1...— .1.). d-nw RC .....W; ...-H . .. i. .e.w.e nuouuc,b T-mo. o .I ..a a. ..h. In .... .. . 4:... . an. 4. 0:... 7.- ...... c...“ luv—P 4H! . ..h. 25F) ‘2‘ 7| 1...». :4 .r at... 4...; ....H: ...... a... cu.: C... .. c... 5.... I 3 JHH. JJHI. c... P... .....H. 7! Au. fix... .....u ....1. ..:... It. a- .4. mm .. ...- H“ C... H .9... .q . C... i. 3.»... 41' 9.. “In. an”... ..:... .o . I.. ...... m. ... 417 0.4.. L»... CL .. .. .. A.-. :4. u .- .; ... ...... ...... ...; ... d: 4...; 3+. J....~.. C . 4Q: 104 Computer Program (Cont'd.) This section computes the intercept and slope for the desired line segment associated with distances 1501 to 5000 feet. D"... mu n7 ...h L .L 7.. Dr. ”...... Du. D..... ”an D .H. L ..h. Dr. M... P” D... ”an D 3.. P... a .D r: .....- .1... DD ..:... ...... ....... D... H... D... ...... B H T.. ....... ..:... ....... MD M... Du ..|.. D... ....H T. ....... ..:... C... n.... ma...“ run C... ..... ...... ...... L .....n.. ...h... ...... .H._... .H...._ ...... L .... ......_ ..bu ..H. ..:. ..._ .....t. .J... 4...; H... ... .... ...- 4.... Au. ...... .1.... 1.... ....... ......_ DH. ....J. ..h. 11 ...». ..-. ..HH. ..-; .w... .w..._ .4. ...; 1-.. ..-. T ... ....... v... c. 4 3 ...... 4. T c... ...- ...... 4. 3 4 3 ...- .4. T c... ...- 3 a- ...... .. ._: ...... 4. c... ..t .. .H. ..4. .H. .... ...... ....... ...- c... ._h. 7- .H. 9 .U .-.. ...... ....... a- c... g... 71H. 9 .H. 1 0,. .H. D... Q... ...._.._ O... O... .H. _H.... .Hu. .H. .H... ....H. .H. .H. "H... ....I.... .-.. cl 1... ...; ...... 1.... ...... 4.... ...... 41 ......M a...» ...... ... ...... a. 4. .....- 4 c... c... c... c... a... c... E c... c... c... 5 c... c... 5 c... c... c... 5 c... c... c... c... ..:.D .2... ....... Du. Mn D"... Du. .L 7.- nfi. M R Du D .H. IL ...”. Du M C... ..t u .-.... ...... ..: “H. MD ...... _ .1 ..:- : DD ..... ...... ....... -D H... F. - ...... D..._ Ft TI ......_ ..:... .....U. DD H... D... ....— ri mi ....... ......._ .H. ....... Du ....... D... D”. D... ..L. C... On ....... D... ....... I I. ‘. . ...m. :I.. ...... ...... tn... ...; .....H. m.... ..:. .1.. 4 .. 5.. ...-.. ...”- .wfi .nn. ...... ....-. . . — d. 1...“: - ...... 7.- .H. .H. n7. 7.- :.... d. ....... ....1 .4. q..- ...... T: ...... 4.. ”...“. d- ....... 7.- d- ...... 35“. ...... ....... .. .. 1......_ 4.. 7-1.473475477 i 47 5:”. in. «.... .....H. ...u... .....H. 1.. ......_ .1.”. 4 En... ...»... as... Q”. .....2. ...ln... 1... m...” .....U. an... _._-H. ...—H. 7... mm. Q... .H. 1 .mL ......“ ...—H. ..._.... ....H. in. ...n. 7.. ...... q... a..- .....- «..-. .....- _...I 7.. .....- Du. .H... D”. On. 0.... On. .....H. .H. .....u. .....H. Q... D... .u... .....- 4 ..H... 4. d. 4 .4 1... 4 a. 4. a- a- A- ...u. 4 a. 4 4 a- 4 a- a. 4 4 a- 4 4 a. 105 Computer Program (Cont'd.) This section computes E2' and prints 82, E3, and E2'. -L ....— .i. I._ . B E ...... 4 H”... ...... m. H .. .. -L C...” Cu u... ...H... Cl; .....H. a-.. ”._:... _H...... ....I.. . _ ..I..... a... .... .4 3.. ...D :1. .....- .w... ...... .m... .w.... .4. Es... . h. .....- ......... Q... ....l... ......_ ......_ ......_ ...; ......_ ...; a... ...; ....... :4. c... c... c... c... 5.... c... r... ...... L n... w- ”A D ...... u- L ...... T- w- L 4 T w- L ...... T D c... T R -. + .1.. 4 __ H H ...- 4 ...... .... ...... p... B ...... ...... P. D ...... 4 .... ...... T ...... u.” R. R ILS HE FHE FHR % S ESE- ".2: T a... _._I.. ....... .H. CI. n...“ 9.... ...L .....L. .....H. .1... ........ Q... .....n. .3. d. ...-..:. .H. ........ ......m .w..._ ......m .w..._ U... n; ...... .4 O... .L...._ .....n. A“... .....w. Q... .1... ......_ 4.4. 4.... Q; A“... ..:... .H; .....s. Au. m... .u... G... ..uu: A”... .....H. ..II... 4 ......... .1.... T! ......._ Q... 4.... ...... an. 4.”... CI”. ...h. 7... .H. .u... .H. 1... ......— ....... .4. ...... ....n. w..- .H. O... ...-H. 1.. fl; ..:... A.- C... ..h. 7.. .H. ...... ...... ...... ......_ ...... ...... ...... 3 ...... 4 4 4 ...... 4 4 4 4 4 4 ...... c... c... .... .... .... c... c... ...... ...... ...... c... cl. =1.. c... C... :.... ...... ...... c... ....H. c... c... c... :J. ...... :|.. :J. :J. :J. E... =|.. c... ...... :.... ”...”. c... APPENDIX D CROP RESIDUE AVAILABILITY PROGRAM, SECTIONS TWO - SIX 106 This part of the program contains sections two through six; the operating procedures and various options are explained below. Comment Area Press Print 1. Initial run a. Load card 1 and 2, all four sides b. Store area of field in memory 00 Area Sto OO -- 2. Section 2 (Water Erosion) -- B key ~- a. Rainfall factor "R" from Figure 10 "R" R/S "R” b. Soil erodibility factor ”K" from Tables 13 and 14 or Figure 9 "K" R/S ”K" c. Field length "L" "L" R/S "L" d. Factor for slope "M", Table 15 "M" R/S ”M" e. Slope gradient "S" (%) "S" R/S "S" f. Cropping management factor "C", Table 6 "C" R/S "C" g. Erosion prevention practice ”P”, Table 16 "P" R/S "P" Calculator now computes annual soil loss "A" if "A" + ”E" (from Sectionl) >”T" (tolerable soil loss, Table 13 and 14, then try a different "C" and "P" h. To try different crOpping management factor and erosion prevention practice 2nd 8' -- i. New "C" factor, Table 6 "C" R/S "C" j. "P" factor, Table 16 "P" R/S "P" New annual soil loss is computed; if "A" + "E" (Section 1) is :_”T", Tables 13 and 14, then note the amount of residue required to prevent erosion. 3. Section 3, total crop and residue yield A key -- a. Estimated or actual yield Yield R/S Yield b. Residue-to-grain ratio, Table 7 Res./Grain R/S Res./Grain c. Weight per unit of yield, Table 7 Weight R/S Weight d. Moisture content in decimal form (i.e., 15% me = .15) at cr0p yield reporting, Table 7 me R/S mc Calculator determines total above-ground yield of grain and residue (dry weight basis); also calculates in-field energy potential. Above ground yield Energy po- tential in- field Computer Program (Cont'd.) 107 Comment Load Press Print 4. Section 4, Available Residue This section has three Options: Option 1 is used to determine amount of crop residue available. Press "C". Option 2 determines amount of grain that is available, press 2nd C'; option 3 will calculate the amount of a portion of cr0p residue available i.e., corn cobs, press 0' a. Determine Option -- Option -- key. C, C', or D' b. Depending on option load; for C Residue Net total amount of residue needed for needed amount soil protection (dry weight) for soil R/S of resi- due available or for C', total amount of grain to be total dry used for conversion to fuel Grain R/S weight of grain avail- able. for 0', enter weight component of total desired residue as compared to units Residue dry of yield, i.e., 9 1b. of cobs per component amount buschel of grain wanted R/S available S. Section 5, the energy balance D -- 3. Estimated field, handling and storage losses in decimal form Losses R/S Losses b. Bioconversion efficiency, Table 17, in decimal form ”Eff” R/S "Eff" c. Energy input into production of crOp component, Tables 8 or 9 Produc- R/S Produc- tion tion d. Energy input into component harvest- ing, Tables 8 or 9 Harvest R/S Harvest e. Energy input into post-harvest processing, Tables 8 or 9 Post Har. R/S Post Har. f. Nitrogen component factor for residue Table 10 "N" R/S "N" g. Phosphorus component factor for residue, Table 10 "Ph” R/S "Ph" g. Potassium component factor for residue, Table 10 "K” R/S ”K" Calculator determines net energy available -- -- Net energy available Computer Program (Cont'd.) 108 Comment Load Press Print 6. Section 6, TranSport Section E 3. Enter, in decimal form, amount of net energy wanted for work, not transport, i.e., 0.75 for work 0.25 for transport Work R/S Work b. Enter energy content of fuel used in transport vehicle, Table 9 Fuel R/S Fuel c. Fuel consumption of transport vehicle Consump. R/S Cons. d. Volumetric space of transport vehicle Space R/S Space e. Bulk density of crop residue, Table 7 Bulk R/S Bulk f. Moisture content of crop component at harvest not at crop yield reporting MC R/S MC Calculator then determines maximum radius each load can be transported. -- -- Radius and total number of loads -- —— Loads END OF PROGRAM. Sample Print Out (English Units) : _, :2 3' "RH -- o :2: "K" - . Dist. Ll. 4 "M" Slope "c" "P" 1’“. '... "All 3,7“ Yield (bu/Ac) ‘- Residue/Grain Lbs/Bushel L Moisture content ‘ at crop reporting 1 lflrhfifiri TOFal dry pounds of ‘ --3‘_-- crop above ground 77HPPHWW“H ! E _ _. _‘ _. 4- :_l L] 2-- ' In-field energy potential (Btu) Grain used (Bushels/Acre) lUCL fifidfiflffil Total dry pounds of """" grain available ' Losses Lu u Conversion efficiency ?4EHMJUCL Crop production energy EEJNJUCL Harvest energy 213000130. Post-harvest energy 0.131] 1 N factors I], (”31:- P factors El, 0123?}: K factors Net energy available .... Ill - IT I 1:": 0:0 Portion of energy for ~ c- work Energy content of fuel Fuel consumption (mpg) Space, ft3 Bulk Density Moisture content at harvest ,. l|| o I ! I] 0:! ' Mile Radius E” No. of Loads Section 2 Section 3 Section 4 Option 2 Section 5 Section 6 Hl‘) Listingiof ..... ”I in”; I ‘ ‘ oa —- ".j w-J- I-m‘ o - r r; .. n Sections and Subroutines T .v' i_T.I.I- 1 U _.. i _l g ' __‘ . l_l ._. -1 ' "I ‘. .' 7" ' . . ”I :' '2', : I .-- . - - .. _ ‘z ‘1' '2 "I -": ’..‘ .'~ ’r .' ' x ' . : 3.. .. ' '-‘ z... x s ‘5 : ~‘ I ' - .1 .> 1- - '._ . . : ‘3 I I '... ‘...‘ z .1. H :— ‘: ‘I' "‘I i 9:" C . 2 . . l - . .. - .. ' ‘ z- .' a a a. -. : -; ... f‘ . fl ..' .' - '. '. s l 110 111 Computer Program, Section 3 This is Section 3 of the total program. The total amount of above-ground -crop and residue are determined here as is the in-field energy potential. This will work for both English and metric units. However, for metric steps 65 through 68 must be changed to 16,000 KJ/kg instead of 7000 Btu/lb. I.‘ '.-I .....L i-" .....I. .....q. ...... 5...; .....t ...; .....L 5.4. I-..| 9...... I l l . anwucnr c l -9 Q u a U u: 9 HI H 5 a S l 1 I 4 n 2 ETD gt- 'fi. ; E"! I" ‘ "le "1': I- (._I :_: ,- l_-l L— :- .... - -'. .-5 L .-: -~. z“: : 9 r - - ~~ “ - ’- uu. -; fl uég +3 an? - :- .-, .* IL' :-. r- - . .° "' - 23th; ;KJ pi.hf LH+;: ‘fit. 2 .- .‘g-j. .-" 4 r. v.:- - _. .-—, .- 5.. Ll a__u ._: -.' i F_ .~ ._3 3-! s: .1, :, _-: {5: I T -- {- -_. 3:' ran-'- -_ . - UJ~ xfl rat U45 U1 3 5‘ {'1 CI .‘.- '1' I "" r .4 ' .4. " -- ‘2' glut: 'rr. -- I [l szh; -;-,;' 3:. g D 5‘: F ,5 3’ 1 2' 1 r ,1 *7 -‘_. r -';. .- UJ, J, J, 4,, ;5 _fl -- - ‘P -- L. - .4 n -' -' I..- r T =.! LJ ! t. '-! :_l 5+ :: ...: 5'1: 1"" 1 l - - a .- r- - - _ U13 +5 ELL u43 T1 38R {-0 u: g- l- - ' - c - .- . I__o l_. 1 :4 :_I a I '_l I-' !_I _-| :_' :: 4 I. ..‘l - l- f. - - c .- -. T U I i .‘I "' 3_l._cl ._:: 3:. g D - '1 ' ’f' C '-I "P '- q. _T ._I 5' .-. i. C "J ._l L. C .-I c ._l r: . a 3'3 L": --| I'_|"_| "”333 'J 03] l_n J¢ £03 ['0 ..n nu '4] £13 I 11:. I-4 -.j (.211 [‘._'| -L. l2! f...) 1:: 417. u 5 . ' q pg 0 6 '5 = 05 2 KIT 0 F 43 STD 053 1 38R 0 3 33 [fi: 359 34 {g D 9 35 + 360 9? PET OLD 43 REL 95; 93 HEW 021 02 02 053 43 REL 032 95 = 063 O? O. 023 42 STD 064 65 K 024 04 04 065 B? ? 035 55 a 055 00 U 326 91 RES 96? 00 D 027 9? PET 063 00 D 023 42 STD 069 95 = as? 24 34 070 42 ST 030 95 = 3?} 03 US 031 42 STD 073 33 3:T 033 35 US DFB 02 3 033 65 K U?4 43 STD 334 53 i era 39 29 835 01 1 fl?& 23 3:? 036 F5 - 077 71 33F 037 91 R b n72 74 f3 usé 99 PP* 1"« We as? OB” 34 . ORR 1% HOV new :* are . : '2 are llZ Computer Program, Section 2 This is Section 2 of the total program, the Water Erosion Section. The amount of soil loss due to water erosion is calculated here. Metric units or English units can be used. The input data presented in the tables and figures for this section are only given in English units. 333 ?g LBL :15 22 EN? 149 94 533 :2 g 115 35 TFH 11% ga x 034 35 CLR 117 33 31H 150 59 PfiL 035 91 R'S 113 43 STD 151 1; '14 525 59 PET 119 15 15 152 55 =' 03? as 2 120 99 :3 152 13 27 033 91 923 121 55 5 151 a; -na 555 95 PET 123 05 5 155 5; Léi 090 95 = 133 DE 5 155 12 :- 591 42 515 124 93 . 15? 25 :12 552 14 14 125 L4 4 152 4% ant 093 53 125 01 1 159 mi '51 094 51 9.5 12? 95 = 15m $9 E- 595 95 PET 125 35 + 151 21 are 595 55 + 129 53 i 152 99 91% 09? g? 2 130 94 4 153 as 5 093 02 2 131 93 . 124 91 2 2 555 92 . 132 95 S 155 as 221 135 55 a 133 55 5 155 22 anw 151 51 154 55 5 :27 5% L' 103 55 9 135 43 REL 1&3 5i ETD 103 21 923 135 15 15 125 n5 -n9 154 99 PRT 13? S4 “ 125 22 93% 105 95 = 125 95 = 121 a; '1 155 52 STD 139 95 + 122 32 9TB 107 15 15 140 93 . 122 22 '29 1:5 51 225 141 00 D 12% E2 211 ID? 9? PET 142 DE 6 EVE ?I 98? 11a 55 w 143 US 5 125 24 f2. 111 93 . 144 95 = 1?? 99 PR. 113 an 0 145 65 1?3 93 FD? :13 a} 1 145 49 REL 179 91 2'2 :14 95 = 147 15 15 ' ’ 113 Computer Program, Section 4 It is comprised of 3 options, which can use either The dry weight amount of the crop component is This is Section 4. metric or English units. determined. Option 1 determines total crOp residue available (dry weight) by entering residue needed for the soil's maintenance. Option 2 determines total grain available (dry weight) by entering amount of grain/hectare or acre to be used. Option 3 determines portion of residue available, i.e., corn cobs by entering amount of portion compared to yield, i.e., 10 lbs. of cobs per bushel of grain. Option 3 [8 H p O D H O f'? p O D N 1 1:0'- 7 ' ! r-I' -‘: ‘ '-l q. ' I lud .0 LDL a); to LEL $2? 99 1P! _ ._ _. - ‘ .- _ l.— '_ l_- : - I... b. t.— 131 ii L Hgfi 1H fi' man «a W. — a - - - .‘ .-‘ .-. 3 .2 : 129 95 RIP 91: 95 212 2:? i; Z z: :" ;‘“ *** “5 52“ 229 25 LL? I l ‘ ; .' "° .-‘. ° 1" . _~ .-. - I 1 .z. .:. :3 1 F. ... ::. _..' 1 t. :3 1 F -:' -':. 8:. C. I: 1 Fl .' I: :-I .' l-' I" '- l '7' -‘ 4 a .- - w- L. .-l ..- J ‘ -, O. -. 104 ?fi FE; 9:: 49 PFi "9’ QQ DH ‘ l-I: ..- c' . . T ‘ - '. r; ‘ L ._I 3;! -. .. ' F_ T 104 94 -. :13 b: ' fig? 9; w - - - _ ' ._U , -l .- .". 1 |_I:'_ ..1 '_I :0! I -‘. 1 .3 .‘I -"I :5 — I T - - - xwu *2 nwL :12 9o “Lu any 24 PFL +07 r‘ 15 wr- n" -- h“ “ ““ 1U; 4U Lb ggu UU UU Qqq n1 q4 100 q: m mm1 x: - “‘“ “ ‘ um :9 ‘ ;;. OJ n 24H 95 2 «Hr afi m P err q a - ”_ M 103 9; 0TH AH? 45 RLL 9&4 no mm. __ - _ --~ -- ~- ;%i 92 tuL 39H 1H In 292 on in ~.- n— -- “‘ ‘3 '- LLJ 4* 9* 5%? NH NH 191 49 .RL 994 :5 2 a I 3; 3' .l- 7; I ~-- *5 ” :49 b» 5 I ‘ I . o q. - - - " - 1,! L; fl- #9: 'U ‘ 9.. .r a _: a . ~~u 49 -LL 244 45 ELL 1 l4 '.l . r." _ --| -_| -' '-I I: '-I C' _ ‘ _. ._: g ._ ;;f—. L. .' .g '3 .4 C' ":1 l'.’ "I: I _'4 1 —. r L ‘ " "" " g. ‘1’._I g_ ._I .L ._3 u- -u ' 917 q: _ , , - y: 73 -;- ~5é #4 r 242 95 = 1&4 1U ;U 3:3 4: STD $37 4? QVD 1:. -‘ :2: .. .- .fi - _ .- — h "f. D L. .-. 3 12b ‘4 — igg 3d 1: 54m ,5 1m - _ a O .c = 12? 42 TD :95 21 Pro 5~q 9. -“ 4rn 1 1‘ it“ :: J L%; (D LEL 1&0 11 i1 :9” IfiJ'f'T n:- ma an 1__ c 2-- -- ~« 25m 52 a; I14 ._J T . I _ .- ,— .- — .. ,- ::: 3: ’l :31 33 Hi? 9”” 3? aN- , , r a :z- i: -:: 252 42 ELL LU} M; U; 955 1? a? firm cc . Lac 2; 5L ,1; L3 5'... tn ._I °. -’_'1 CT .1 ":1 “:I '_.' 3 T _ _ _ _ _ L...‘_I‘? '..'I.'_. I": ‘l 3 ---.' I... ‘1... '.L _-u :2 ; Qfiq fl? 9 23"“; {.4 -:| .1 :- ._ __ - :- - ‘— 5- M. “W wc- 1w “T - ;Jh a; HID a c we m °‘ ' L: 3‘3 . 3 1:! . I "a C '7 "I I- "’0 - --: ‘ aJ' ;4 ;H a 3-3 3:- '4' :3: . 3.: L ”‘0 C' 2" ‘0 -;2 l 0 O :r - 31.: _t '- ' 20? 35 33 i2; $7 :gt __.‘ '.-. ..: -. ..:. 3. i A ':'L..'F'. ,'_°_ .- I_x "3' ._l "" "t ‘- “0 .4 r" ' ' whH a : 9H9 4? TR 7i? 1? 4? ___‘ _. z__ . L '3'». .12.! E‘- 'T 91 n g 3 -‘- TS '. f L 1 i: E ‘ ;.' T” :f‘ J9m' flfl HLW’ Li: :3 'fl T1? 9? 'T s... A 5.. ‘-'(.. 4 i 114 Computer Program, Section 5 This is Section 5, the Energy Balance. It is set up for English units now. To change into the metric units change: Steps 279 to 282 from 7,000 to 16,000. Steps 316 to 320 from 27,778 to 63,500. Steps 330 to 333 from 4,960 to 11,340. Steps 344 to 347 from 3,968 to 9,070. 322 72 :31 939 9? g3$9 14 II .335 43 FIL. 365 35 CLR 306 U3 US 223 53 {j 39? 95 = 32? Q1 1 333 43 EYE 2&3 ?S - 33? 14 14 269 91 RES BED 43 REL EFD 9? PET 311 12 12 2?1 54 B 312 65 E EFE 65 x 313 91 RPS 3?3 43 RC 314 99 ”RT 374 13 13 315 65 H 295 95 : 316 02 2 276 43 ST 31? 0? 7 927 19 19 313 3* 7 -...I: as— h. --.._ ..l l 3?3 65 i 319 0? ? 37? 07 ? 330 33 3 238 80 D 321 35 = 331 30 D 322 42 STU 233 00 U 323 15 15 333 95 = 324 43 REL 334 43 5TB 325 12 12 235 13 13 336 65 I 236 55 2 32? 91 Rf? 23? 91 R23 323 3? PET 333 99 PR 329 65 K 339 75 _ 330 04 4 392 91 222 331 39 9 291 9? PET 333 96 9 393 65 x 333 DD 0 293 43 REL 334 95 = 294 DH 00 335 42 STD 295 F5 - 336 16 16 296 T E’S 337 43 REL 22? 99 PET :12: :2 12 393 RS 339 $5 399 43 ”CL 342 91 293 300 30 03 392 9? PP? 221 25 - 34? 93 an” __ - - a ._ .-. 322 91 2 5 343 i5 303 9? PPT 11.5 Computer Program, Section 5 (Cont'd.) m...“— a.-. :L A... IL :1. .L ..h. L 7.. mu 0.... T... nu Q. T1 Du ..u- __... O... .H... .....H. ... ..:... ..I. ..:... ...... _ ..ul.. 4.... . .. . 1... _ ....i.. 41. : Ti. 41 pi ......_ v ..... ..:... r4 Du H.HH C.— : fin; ....... “up. mm” mm“ D...” ....... 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Q. ......H. .....H. ..H. .H. ....u. .H. .H. .Hu. .H... ......... 4-.. l 1... 1... .. . 4.... ...... 3 3 3 3 .-.... 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 3 ..4 ..4 ...... ..4 .4 ..4 ...- ..4 ...... ..4 ..4 ..4 ..4 ..4 ..4 ..4 ...- Computer Program (Cont'd.) Subroutine Subroutine V X is used to round off the various output data generated throughout the program. ~v- .AL. ..- - Im-h l__'l a1") l_|_l .J. C. I“! ~-’ .' .' Ell ‘1‘ -_1 T' T C1 ._ L.' L— »? t3 3" "J .-* :" '-.-' —.' 2.! :_1 ._: -. .; .- -. 4. -' -: .: ' '— C “I? T.“ i -1 .3. 2T. 2. .Q ." '-l " C -— ‘45; fi-‘ ~ .4. -'-'-. ::=-. z— r»- 4 t- ._'= --_| O 1" _ . . .4. " .4 .4 -‘ ’ 1». T 4b4 4U 1HJ .