THE EFFECT OF NITROGEN FERTILIZER ON THE YIELD AND PROTEIN CONTENT OF ALFALFA AND COMPANION CROPS By CLARENCE RALPH CARTER AN ABSTRACT Submitted to the School of Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Soil Science 19 59 Approved; ABSTRACT The effect of nitrogen fertilizer on the yield and protein content of alfalfa and companion crops was studied under field and greenhouse conditions. In the greenhouse study five rates of ammonium sulfate were applied to six soils, Brookston clay loam, Miami loam, Oshtemo loamy sand, Conover loam, Hillsdale loam and Fox sandy loam. planted with inoculated alfalfa seed. Each was Three cuttings of alfalfa were removed for yield and protein analysis. The soils were analyzed before the study was Initiated and again at the end of the experiment for total nitrogen. Three soils of varying composition, a Brookston clay loam on the Lee Ferden farm at Chesaning, Michigan; a Hills­ dale loam on the University farm at East Lansing, Michigan and a Fox sandy loam on the W. K. Kellogg farm at Battle Creek, Michigan were used for extensive field plantings of alfalfa and companion crops with four rates of nitrogen. Spring plantings were made with oats, barley and wheat. Fall plantings consisted of alfalfa seeded alone in August and alfalfa seeded in wheat. Nitrogen was applied at planting time and as a topdressing on the wheat. Four additional soils, Oshtemo loamy sand in Barry county, Ockley sandy loam in Calhoun county, Belfontaine sandy loam in Jackson county and Conover loam in Lapeer 1 2 county were selected for a source of nitrogen study applied as a topdressing on established stands of alfalfa. The average yield of alfalfa grown on six soils in the greenhouse increased in a linear manner when 0, 20, 40, 80, and 160 pounds of nitrogen per acre was applied* The yields obtained with additional nitrogen were significant at the 0.01 percent and 0.05 percent level respectively, on the Oshtemo loamy sand and the Miami loam soils. The average protein content increased in a similar manner when additional nitrogen was applied; however, increases were not significant. these The amount of total pro­ tein produced, increased likewise and was significant at the 0.05 percent level. The nitrogen content of the soil was less after the removal of three cuttings of alfalfa. The analysis indicated that 160 pounds of nitrogen per acre was needed to maintain the nitrogen level in the soil. Applications of nitrogen fertilizer were very benefi­ cial in increasing the yield and protein content of the companion crops in this study. Significant increases were obtained where twenty pounds of nitrogen per acre was used on oats on a Fox sandy loam at the Kellogg farm and on bar­ ley on a Brookston clay loam at the Ferden farm. An appli­ cation of twenty pounds of nitrogen per acre on wheat at planting time gave a significant increase in yield over the check plots at all three locations. Plots topdressed with 20 pounds of nitrogen per acre produced a significantly higher yield of wheat on a Fox sandy loam at the Kellogg 3 farm and on a Brookston clay loam at the Ferden Farm than where no nitrogen was used. Severe lodging of these companion crops was not en^ countered until 80 to 100 pounds of nitrogen per acre had been applied either at planting time or at planting time plus topdressing. The test weight was not seriously af­ fected even when the application of nitrogen was 100 pounds per acre. A significant increase in the protein content was ob­ tained for oats on the Fox sandy loam at the Kellogg farm and on the Hillsdale loam at the University farm, in barley on the Brookston clay loam at the Ferden farm and smaller increases were found in the wheat at all three locations. The yield of alfalfa following oats, barley or planted alone in August was not influenced by the addition of nitro­ gen fertilizer. Small increases as well as decreases were found without any definite patterns or trends established. The protein content was much higher in some cases where ni­ trogen fertilizer was applied. Nitrogen fertilizer increased the yield of alfalfa when fall planted in wheat and additional nitrogen applied as a topdressing in the spring gave a significant increase on the Fox sandy loam at the Kellogg farm. The same ferti­ lizer treatment gave a small but insignificant increase when spring planted in wheat and additional nitrogen at planting time resulted in a decrease* Significant decreases in yield resulted also on the 4 Brookston clay loam at the Ferden farm with a topdressing of 20 pounds of nitrogen per acre on both fall and spring planted alfalfa in wheat. The protein content was increased in all cases where nitrogen fertilizer was applied. Nitrogen topdressings on alfalfa with three sources of nitrogen failed to produce a significant difference in yield or protein content. THE EFFECT OF NITROGEN FERTILIZER ON THE YIELD AND PROTEIN CONTENT OF ALFALFA AND COMPANION CROPS By CLARENCE RALPH CARTER A THESIS Submitted to the School of Graduate Studies of Michigan State University of Agriculture and Applied Science in partial fulfillment of the requirements for the degree of DOCTOR OF PHILOSOPHY Department of Soil Science 19 59 ProQuest Number: 10008544 All rights reserved INFORM ATION TO ALL USERS The quality of this reproduction is dependent upon the quality o f the copy submitted. In the unlikely event that the author did not send a com plete manuscript and there are missing pages, these will be noted. Also, if material had to be removed, a note will indicate the deletion. uest ProQuest 10008544 Published by ProQuest LLC (2016). Copyright of the Dissertation is held by the Author. All rights reserved. This work is protected against unauthorized copying under Title 17, United States Code Microform Edition © ProQuest LLC. ProQuest LLC. 789 East Eisenhower Parkway P.O. Box 1346 Ann Arbor, Ml 4 8 1 0 6 -1 3 4 6 \‘l 0 ACKNOWLEDGEMENTS This investigation was initiated under the direction of Dr. Richard M. Swenson of the Soil Science Department and after his promotion to Assistant Dean of Agriculture, the work was continued under the direction of ^r. H. D. Foth. The author wishes to express his appreciation to Mr. Dale Friday and the Nitrogen Division of Allied Chemical and Dye Corporation for supplying a part of the funds which made this work possible and to Michigan State University, Departments of Graduate Studies and Soil Science for their financial assistance through a Graduate Teaching Assistantship. The author also wishes to thank Dr. R. L. Cook, Dr. J. F. Davis and Dr. H. D. Foth for their assistance, criti­ cisms and untiring efforts that were rendered throughout this research and the preparation of this manuscript. i VITA Clarence Ralph Carter candidate for the degree of Doctor of Philosophy Final examinations January 23, 1959. 10s00 A.M. Room 210 Agricultural Hall Thesis; The Effect of Nitrogen Fertilizer on the Yield and Protein Content of Alfalfa and Companion Crops. Outline of Studies; Major subject; Soil Science Minor subjects; Plant Physiology, Statistics and Physical Chemistry. Biographical Items: Born; February 28, 1922, Panama, Oklahoma Married; September 9, 1947 to Betty Sue Parker, and have two children, a boy, Clarence Irving and a girl, Sandra Sue. Undergraduate Studies: Oklahoma A & M College, 1951- 1953, B.S. degree with major in Agronomy. Graduate Studies; Oklahoma A & M College, 1953-1954, M.S. degree with major in Soil Science and minors in Botany and Animal Husbandry. Michigan State University, 1954-1958. Expe rience: Born and raised on a farm. Served three years in United States Army Air Corp dur­ ing World War II including overseas duty in North Africa, Burma, China and India. Veterans Agricultural Training Program Instructor for four years. Laboratory Technician, College, Soils Laboratory, Oklahoma A&M Stillwater, Oklahoma for tv/o years. One year with the U. S. D. A., A. R. 3 .~ ■ Soil fertili­ ty research investigation. Currently employed by Louisiana State University, North Louisiana Hill Farm Experiment Station, Homer, Louisiana. Six Publications Member of Sigma Xi Member of American Society of Agronomy iii TABLE OF CONTENTS Chapter I. II. III. IV. Page INTRODUCTION.................. REVIEW OF LITERATURE 1 .. ............ Companion Crops• ••..‘•••-•e....,,..*.......... Symbiotic Fixation of Nitrogen by Alfalfa.. Establishment of L e g u m e s . e♦....... 7 11 14 METHODS OF EXPERIMENTATION....................... 19 Soil Pot Studies in the Greenhouse,....*..# Methods Used in Field Studies.............* 19 21 RESULTS AND DISCUSSION............. Soil Pot Studies in the Greenhouse...... Results Obtained from Field Studies........ Wheat as a Companion Crop.. .......... r Sources of Nitrogen........ V. VI. VII. 3 24 24 31 40 55 SUMMARY AND CONCLUSIONS................... 60 LITERATURE CITED......................... 63 APPENDIX.......................... 68 iv LIST OF TABLES Table 1* 2. 3. 4. 5* 6* Page Composition of soils used in the greenhouse study....... ......... 19 The location, soil type and chemical analysis of soils used in sources of nitrogen study......• • 23 The effect of rates of application of ammonium sulfate on the mean yield of alfalfa grown in the greenhouse in 1955 and 1956, ••.•••••••••.. 26 The effect of rates of application of ammonium sulfate on the mean percent protein in alfalfa grown in the greenhouse in 1955 and 1956* ....• 28 The effect of rates of application of ammonium sulfate on the total protein produced from four pots and three cuttings of alfalfa. ••••••••••• 30 The effect of rates of application of ammonium sulfate on the residual percent nitrogen found in the soils after the removal of three cut­ tings of alfalfa. ............. .*•»»«...... 30 7. The effect of rates of application of ammonium sulfate on the yield of grain harvested in 1955. 32 8. The effect of rates of application of ammonium sulfate on the percent.protein of grain har­ vested in 1955* •••••• * 33 The effect of rates of application of ammonium sulfate on the mean yield of alfalfa. *••••*••• 34 The effect of rates of application of ammonium sulfate applied in 1955 on the percent protein found in alfalfa hay harvested in 1956. ••••••• 37 The effect of rates of application of ammonium sulfate applied in 1955 on the percent protein found in alfalfa hay harvested in 1957. ....... 38 9. 10* 11. 12. The effect of rates of application of ammonium v sulfate on the yield of wheat on a Fox sandy loam soil in 1956. .... ••a.*****.**.......... 13. 14. 15. 16. 17. 18. 19. 20. 21. 22. 23. 24. 42 The effect of rates of application of ammonium sulfate on the yield of wheat on a Hillsdale loam soil in 1956. ..... 43 The effect of rates of application of ammonium sulfate on the yield of wheat on a Brookston clay loam soil in 1956. 44 The effect of rates of application of ammonium sulfate on the percent protein ofwheat grown on a Fox sandy loam soil in 1956. ••••••••••«• 45 The effect of rates of application of ammonium sulfate on the percent protein of wheat grown on a Hillsdale loam soil in 1956. •••••»•••••• 46 The effect of rates of application of ammonium sulfate on the percent protein of wheat grown on a Brookston clay loam soil in 1956. ..••••• 47 The effect of rates of application of ammonium sulfate on the test weight of wheat grown on three soils in 1956. 48 The effect of rates of application of ammonium sulfate on the yield of alfalfa following wheat on a Fox sandy loam soil in 1957. •••••• 50 The effect of rates of application of ammonium sulfate on the yield of alfalfa when fall planted in wheat on a Brookston clay loam soil in 1957. ...... 51 The effect of rates of application of ammonium sulfate on the yield of alfalfa when spring planted in wheat on a Brookston clay loam soil in 1957. .................. ^ * 52 The effect of rates of application of ammonium sulfate on the percent protein of alfalfa hay following wheat on a Brookston clay loam soil in 1957.......................................... 53 The effect of rates of application of ammonium sulfate on the percent protein of alfalfa hay following wheat on a Brookston clay loam soil in 1957. ..... 54 The effect of sources of nitrogen applied as a topdressing on the yield of alfalfa hay harv i vested in 1957. . • • • . • • ......................... 57 The effect of sources of nitrogen applied as a topdressing on the percent protein of alfalfa hay harvested in 1957. ................. ... 59 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on Miami loam. 68 The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1955 on an Oshtemo loamy sand. .......... ........... 69 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1956 on Hillsdale loam. ........ 70 The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1956 on Hillsdale ..... . loam. 71 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1956 on Conover loam. .... . 72 The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1956 on a Conover lo am fi 75 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on Miami loam. 74 The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1955 on Miami loam. 75 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1956 on Fox sandy loam. .••••••• 76 The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse on Fox sandy loam. ... 77 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on a Brookston clay loam. . 76 vil 12. 13. 14. 15. 16. 17. The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1955 on Brookston clay loam. V’9 The effect of rates of application of ammonium sulfate on the yield of alfalfa following oats on a Fox sandy loam soil. ••••«••• ••„•••• 80 The effect of rates of application of ammonium sulfate on the yield of alfalfa following oats on a Hillsdale loam soil. ••••••••••••.•• 61 The effect of rates of application of ammonium sulfate on the yield of alfalfa when seeded alone in August on a Hillsdale loam soil. .... 82 The effect of rates of application of ammonium sulfate on the yield of alfalfa following barley on a Brookston clay loam soil. •••.••.* 63 The effect of rates of application of ammonium sulfate on the yield of alfalfa when seeded alone in August on a Brookston clay loam soil. 84 v i ii LIST OF ILLUSTRATIONS Figure 1. Page The effects of ammonium sulfate on the yields of alfalfa* ...... **•••#•«•«* ix 25 I. INTRODUCTION Prior to 1954, research investigations indicated that nitrogen fertilizer applied at planting time may increase the yield and protein content of alfalfa under greenhouse conditions. They also indicated that nitrogen fertilizer improved alfalfa seedings when seeded with wheat in the fall and increased the yield of the companion crops. The purpose of this study was to continue this work using the same soils as well as additional soils in the greenhouse and to secure several locations throughout the state for field trials. Farmers of the state of Michigan are encouraged to produce and feed a good quality high protein hay. Cost of production is decreased because less of the costly protein supplement is required. Agricultural Statistics, 1954, reported that alfalfa hay production for the state of Michigan is on the decline in acreage and that the average yield is only 1.5 tons per acre • This experiment was proposed to study further the ef­ fect of rates of nitrogen fertilizer applications on the yields and protein content of alfalfa under greenhouse con­ ditions as well as alfalfa and companion crops under field conditions. Four rates of nitrogen were applied to four 1 plantings which included (a) alfalfa and oats or barley spring planted, (b) alfalfa planted alone in August, (c) alfalfa seeded with wheat in the fall and (d) alfalfa over seeded in wheat in the spring. In addition to the above mentioned plantings, four well established stands of alfalfa were topdressed with 30 pounds of nitrogen per acre from several sources to study its effect on yield and protein content of alfalfa XX* REVIEW OF LITERATURE The literature dealing with alfalfa and companion crop is voluminous as well as that covering nitrogen hut there is little which deals with the direct application of nitro­ gen to alfalfa* For many years following Hellriegel and Wilfarth's dis covery that legume plants differed from nonlegume plants with respects to nitrogen fertilization and the validation of this fact by Schloeslng and Laurent, who showed that the loss of nitrogen from the air was equal to the gain in ni­ trogen in the soil plus the amount of nitrogen found in the plant, very little work was carried on with nitrogen com­ pared to some of the other nutrients. During recent years several investigators (1) (5 ) (S) (17) (26) have found that various increments of nitrogen will increase the yield of alfalfa and companion crops as well as the protein content* and use of The discovery, formulation, (1) (26) (47) (56) has been a great aid in the study of nitrogen uptake and utilization by legumes as well as other plants, Waksman (52) working with soil from ten plots of a ni­ trogen availability experiment found that crop production was parallel with the number of microorganisms that de­ veloped upon the plate. If the manured plots were excluded 4 the plots receiving ammonium sulfate, acid phosphate, muri­ ate of potash and lime were the best in crop production and produced the highest number of organisms. by the plots receiving acid phosphate, This was followed muriate of potash and sodium nitrate, which shows that ammonium sulfate was more effective in promoting the growth of both plants and micro­ organisms, Batham (4) indicated that ammonium sulfate is more effectively nitrified and taken up by the plant than any of the amino acids. He also stated that nitrogen in compounds of both ring and chain structures is more readily nitrified than nitrogen in straight chains and that sulfur in cystine appears to depress nitrification to a certain extent. Meiklejohn (29), in her review of the nitrifying bac­ teria, discussed the production of salt petre in the four­ teenth century by the process of nitrification as well as the history concerning the discovery of the bacteria respon­ sible for the process. trate formation, In her list of conditions for ni­ she stated that the pH for nitrosomonas should be between 6.0 and 9.0 and for nitrobacteria 6.3 and S.4. The necessary minerals are calcium, phosphorus, nesium, iron and copper. mag­ Zinc is not needed and manganese is toxic in mixed cultures. Peptone is poisonous, especial­ ly 9 In the free amino acid methionine. A favorable C;N ratio for nitrification was upset by the addition of wheat straw by Stojanovic and Broaabent (44). In a study of the immobilization and mineralization rates 5 of nitrogen, they found that 95 percent of the nitrogen added was tied up in two to six day intervals or at a rate of thirty-eight pounds per day. At the same time, only eighteen pounds of nitrogen was liberated. The rate for nitrate nitrogen was faster and 99 percent or fifty-six pounds per day were tied up and thirty-four pounds were rele ased. This study shows that microorganism assimilate ni­ trogen faster than growing plants while the release is very rapid if'the soil conditions are favorable. The authors also stated that nitrogen used by plants is furnished partly by organisms, even, when nitrogen fertilizer has been ap­ plied. There has been quite a discussion on the sources of nitrogen for crop production. Tisdale et al (46) stated that the ultimate role of nitrogen in plant nutrition is its conversion into proteins which are essential in the make up of protoplasm in all living matter. The authors stated that the nitrate and ammonia ions are taken up by the plants Aside from their solubilities, nature, their organic or inorganic their movement in the soil, and their acidity or basicity effect in the soil; the cost is probably the most important factor in making a choice. Hutchinson and Miller (22) found that out of twelve ni­ trogen materials, urea was the best for nitrogen uptake and bartituric acid for total weight when peas were used as the indicator crop. Acetamide produced as much weight of peas as bartituric acid but less nitrogen was taken up. The 6 pea plants assimilated 12.5 mg. nitrogen from ammonium sul­ fate compared to 8.5 mg. for formimide and 7.0 mg. for all­ oxan. All of these sources were classified as readily as­ similated types of nitrogen. Treggi (48) obtained the highest yield of lupines and the strongest plants from sodium nitrate in sand and soil cultures, particularly, in the presence of high potash. He attributed this difference to ion interference of Na-K and Ca~Mg, respectfully, which resulted in a differential de­ velopment of tissues. In relation to the development of tissues, Bosemark (7) stated that the increase in root length in cases of nitro­ gen deficiency is due to increased cell length, whereas, growth inhibition at high nitrogen levels is the result of the combined action of reduced cell multiplication as well as elongation. With increasing amounts of nitrogen, the natural auxins in the root increased and this could be the explanation for the different sensitivity of auxin (I~nap~ thylacetic acid) and anti auxin (3 until 300 pounds had been applied to soybeans and 1000 pounds per acre to alfalfa* The nitrogen content of plant roots has been studied by Mckean et al (27) in relation to their cation exchange capacities, A corelation coefficient of 0,86 was found be­ tween the cation exchange capacity and nitrogen content of the roots of twenty species. The authors found that plants with high cation exchange capacity preferred Ca over K or Na and the reverse was true for plants with a low cation ex­ change capacity. This would enhance the uptake of Ca and Mg which would aid in the release and uptake of phosphorus and depress the uptake of monovalent cations such as K, This could explain why it is necessary to apply larger amounts of K when the nitrogen supply is increased, Companion Crops The establishment of alfalfa can be exceedingly diffi­ cult, depending upon the companion crop, tions, supply. the weather condi­ the fertility level of the soil, the pH, and moisture Work in this direction has been in progress and 8 must be continued because new varieties of both alfalfa and companion crops are being released for commercial use. Briggs and Harrison (6) used three varieties of oats, three varieties of barley, German millet, soybeans, sudan grass and buckwheat as companion crops and found all of these were satisfactory in alfalfa plantings if they were removed early either for grain or hay* The best alfalfa yields were obtained with oats and barley cut for grain at a height of three inches and the straw removed. Smith et al (40) studied the rate of seeding of oats as the companion crop with alfalfa and red clover and con­ cluded that there was no significant difference between the rates ranging from one-half to three bushels per acre. However, their stands were very weedy and the stands on the sandy soils were poor following the high seeding rate. In many cases it is important to secure a high yield of the companion crop, with high quality or protein content, as well as the establishment of the alfalfa. quence, As a conse­ many investigators have applied high rates of ni­ trogen to the companion crops by making seasonal topdressings. Gardner (15) reported that the protein content of win­ ter wheat and winter and spring oats was increased from 11.37 to 12.00 percent with a mid-April application of 200 pounds per acre of nitro-chalk. With another application of 200 pounds per acre in mid-June, was increased to 13.67. the protein percentage Hutchinson and Martin (23) listed the average protein of English oats as 11*56 percent and 12*50 percent for wheat. They also stated that it may vary a great deal in oats depending upon the percent that is ker­ nel and percent that is husk. as 0*2 percent in protein. Varieties will vary as much Hunter (21) reported that yields of barley were lowered with delayed applications of nitrogen but the percent of protein was increased. When split appli­ cations of 100 pounds of sodium nitrate were made, large Increases in yield and protein content were combined. 32 Yatozawa (56), experimenting with radioactive P , showed that topdressing of wheat with nitrogen gave an in­ crease of phosphorus uptake and accumulation. Mulder (30) has pointed out a connection of magnesium nutrition in re­ lation to nitrogen fertilization. In the absence of mag­ nesium, ammonium sulfate did not produce as good a yield as calcium nitrate. This could be caused by an unfavorable soil reaction due to the addition of the ammonium sulfate. In the case of calcium nitrate, the plant could be using calcium to a greater extent than magnesium. Peterson (33), reporting the results of an eight year study of the effects of nitrogen on yield and protein con­ tent of wheat, showed that commercial nitrogen increased the yield or protein content or both and in no case was there a decrease in yield or protein content. When the protein content was up, there was a decrease in yellow ber­ ry. Forty pounds per acre appeared to be the most economi­ cal rate to apply. For early spring applications the ni- 10 trate form was the "best, however, either nitrate or ammonia were satisfactory for fall applications. He also reported that the test weight was seldom increased but never de­ creased. Hobbs (20) at Kansas State University found that thir­ ty-seven pounds of nitrogen per acre gave an increase in yields of 20.2 percent and at the same time increased the protein content from 11.7 to 12.3 percent. The greatest yield increases were obtained on plots with a high phos­ phate content which was more conducive to tillering and producing a more plump kernel. There was a slight reduction in test weight but it did not affect the yields. Williams and Smith (55) at the same station found that nitrogen and phosphorus increased the yields of wheat at all locations tested but potassium had no effect. A pre­ plant broadcast application of nitrogen was as good as later applications. The protein content was increased with ni­ trogen, nitrogen and phosphorus, nitrogen and potassium, but was decreased with the application of phosphorus. The test weights varied from one location to another due to ni­ trogen but there was no difference in the source of nitro­ gen used. In contrast to the previously mentioned investigations, McNeal and Davis (28) found nitrogen hastened the heading date from one to four days with nine varieties of spring wheat and nitrogen did not reduce the test weight. The au­ thors also stated that there was no significant difference 11 in the protein content even with 100 pounds of nitrogen per acre and that the interaction between varieties and treat­ ments was not significant. Symbiotic Fixation of Nitrogen by Alfalfa Many lengthy and varied discussions have been pub­ lished concerning the amount of nitrogen fixed by legumes as well as the effect of available nitrates on symbiotic fixation. Alios and Bartholomew (1), worked with seven le­ gumes and four grasses grown in one-half gallon pots of ex­ ploded vermiculite and fed with a nutrient solution con­ taining up to 432 mg. of nitrogen per pot, reported the mag­ nitude of nitrogen uptake. They found that nitrogen fixa­ tion decreased while nitrogen uptake increased with increas­ ing rates of nitrogen. The authors also stated that nitro­ gen fixation was never completely inhibited nor was all of the nitrogen adsorbed. Lower rates of nitrogen tended to increase growth and uptake of nitrogen more than it did to decrease fixation. However, high rates had less effect on growth but a greater effect on fixation. G-iobel (17) at the new Jersey Experiment Station re­ commended some combined nitrogen because it is desirable and highly beneficial for maximum infection and nodule develop­ ment as well as root development in the early stages of growth since the alfalfa seed are small and do not contain much nitrogen. He also found that the yield and percent of protein increased proportional to the nitrogen fertilizer 12 applied. There was no nitrogen fixed during the growth of the first crop but beginning with the second crop nitrogen fixation took place very readily and the average fixation was found to be 150 to 200 pounds of nitrogen per acre. The amount fixed was inversely proportional to the amount of nitrogen in the soil. Inoculated and non-inoculated alfalfa absorbed nitrates at the same rates and nodule de­ velopment was hindered by large amounts of nitrates even when added in small quantities over a long period of time. In 1944 at the Delaware Experiment Station, Davis (9) observed a condition of nitrogen deficiency in alfalfa and upon close examination found no nodules on the yellowish stunted plants. On the normal green colored plants, nodules were present in large numbers. This situation was studied by applying forty-two pounds of nitrogen, phosphorus and potassium alone or in combination in the spring. When the plots were harvested twenty-nine days later, it was obvious that nitrogen alone was responsible for the greatest in­ creases in yield. Lyon and Brizzell (25) in a study of nitrogen accre­ tion by legumes found that alfalfa fixed 268 pounds of ni­ trogen per acre per year. It is of interest to note in this work that field beans caused the greatest reduction in nitrogen. The authors stated that when alfalfa is grown in a soil containing 0.12 percent nitrogen, the gain in the soil nitrogen was less than at the low level of 0*084 per­ cent nitrogen but the hay contained a higher content of 13 nitrogen. McAuliffe et al (26) using N 15 found that twenty-five pounds of additional nitrogen almost stopped nitrogen fixa­ tion in a fescue-clover sod and that fifty pounds of nitro­ gen completely inhibited fixation. The authors reported that in another experiment 50 pounds of nitrogen did not stop fixation. check. However, the yields were the same as the In one experiment 50=100 pounds of nitrogen in­ creased the yield of the mixture by 300-1000 pounds of dry forage per acre. Walker et al (53) reported that 30 per15 cent of the N was lost by denitrification and where clov­ er was grown, part of the nitrogen was converted to the or­ ganic form before it was recovered. They also found no evi­ dence of the transfer of nitrogen from the clover to the 15 grass. Thornton (47) also working with N and four legumes found that nitrogen aided or enhanced the fixation of ni­ trogen and also increased the yields and protein content of sweet and red clover. He also recommended supplemental ni­ trogen for maximum growth of soybeans. Application at planting time depressed nodulation but the nitrogen was re­ covered in the roots and tops. In contrast to early appli­ cations, which depressed nodulation by 50 percent, late ap­ plications of nitrogen went to the seed. The quality of legumes for green manure or the effect of fertilizers on root-top ratios have been investigated by several workers (3) (10) (14). Baker et al (3) found that a 20-40-^Q fertilizer gave a significant increase in yield J_4fc of both top and roots of red clover and a 40-80-80 fertili­ zer on sweet clover gave a significant response at the one percent level for both tops and roots. Davis and Turk (10) working with alfalfa and sweet clover found that fertili­ zers increased the amounts of nitrogen, phosphorus and po­ tassium in the roots and tops but did not increase the cal­ cium and magnesium. nitrogen, The earlier cuttings contained more decomposed faster, for the nitrogen treatment and fertilizer treatments in general, and liberated more ammonia and nitrates. A corelation analysis was carried out by Fribourg and Johnson (14) on the yields and nitrogen content of roots and tops of six legumes. They found that sweet clover fertili­ zed with 135-150 pounds of nitrogen per acre gave the high­ est yields with equal roots and tops followed by alfalfa fertilized with 60“120 pounds of nitrogen per acre with a higher top-root ratio. The corelation between dry matter of tops and roots versus the nitrogen yield in tops and roots was 0.976. For dry matter yields of tops versus the nitrogen yield for both top and roots, the corelation co­ efficient was 0.936. Establishment of Legumes The following papers deal primarily with fertilizers used in establishing legumes. Suman (^3) stated that the initial fertilizer is the key to establishing clovers on coastal plain soils and recommended 565 pounds per acre of an 0-15-15 fertilizer on sandy soils of low fertility. 15 There was no Increase in yields above 950 pounds of the fertilizer* Woodhouse and Charablee (49) used 500-500 pounds of an 8-8-8 fertilizer per acre at seeding time and topdressed with 85-50 pounds of nitrogen annually for a mix­ ture of annual grasses and legumes. For perennial legumes and grasses, they recommend 1000 pounds of a 8-12-18 ferti­ lizer at planting time and topdress with phosphorus and potassium. The authors definitely recommended 10-20 pounds of nitrogen for pure stands of legumes at planting time. Swenson"** found in a greenhouse experiment with alfalfa that nitrogen applied at the time of seeding gave increases in both yield and protein content. Field results also in­ dicated that nitrogen was beneficial in establishing alfalfa.. Gross et al (19) working with varieties of alfalfa found that varieties differ significantly in yield. They also differ with nitrogen fertilizer but the interaction of varieties and treatments was not significant. Rendig (58) applied calcium sulfate to a sulfur deficient soil and found that 200 and 400 pounds of calcium sulfate increased the yields as well as the sulfur content and Increased the percent of nitrogen in the first harvest. There was no sig­ nificant change in the four following harvests. The amide nitrogen was increased in the first, third, and fifth har­ vests but the free alpha-amino nitrogen remained the same. The protein was not enriched in methionine by the addition of sulfur but the synthesis of some reduced sulfur contain^Unpublished data. 16 ing compound in the unfertilized alfalfa was impeded, pre­ sumably by a lack of available sulfur. House et al (67) reported a reduction in percent stand of clover in a. mixture of grasses from 50 percent to 5 per­ cent with the application of 160 pounds of nitrogen per acre* The authors reported a significant increase of crude protein for three of the four types of harvest due to nitro­ gen fertilizer. Wagner (50)(51) comparing legume nitrogen with fertilizer nitrogen in relation to protein production found that clover seeded in the mixture produced a higher yield than did the grass alone topdressed with 160 pounds of nitrogen fertilizer. Ladino clover fixed 150 pounds of nitrogen per acre when grown with orchard grass or tall fescue. Prince (35) found, as others have reported, that plots receiving 90 pounds of nitrogen per acre gave a sig­ nificant increase in yield of a mixture of rye grass and clover over those plots where 60 pounds of nitrogen was used. The effect lasted for two cuttings, and the nitrogen content was higher where the 90 pounds of nitrogen was ap­ plied. There was a higher percent of clover where the 30 pound rate was used. Four cuttings exhausted the nitrogen supply and the clover fixed only 25 pounds of nitrogen while 69.4 pounds were removed in the hay leaving the rye grass deficient in nitrogen. Swanson (45), after studying the effect of growing al­ falfa for long periods of time, concluded that the nitrogen content of the soil was not equal to the nitrogen content 1? under sod except in semi-arid areas. It was greater here and also in the more humid areas the nitrogen content is greater under alfalfa than in groin cropped soils. He also stated that alfalfa has not added materially to the amounts of nitrogen now present except in the semi-arid areas al­ though alfalfa has prevented a further loss in soil nitro­ gen and has maintained an equilibrium. During the last few years several workers (2) (5) (6) ill) (16) (32) (42) (54) have published their results along this line indicating a very popular field of work. There was a wide range of fertilizer recommendations given in these reports which indicated that each location must be given special consideration. Griffith (18) has pointed out the high requirements of the mineral constituents of alfalfa and the removal of these elements from the soil. Larson et al (24) working with phosphate deficient soils in Iowa has shown that small ap­ plications of phosphate were depleted in a very short time whereas heavy applications of phosphorus were still produc­ ing good yields of alfalfa hay with a high phosphate content after four years. Gerwig (16) showed a response of alfalfa to 300 pounds of K2O per acre and recommended 200 pounds of K^O as well as twenty-five pounds of nitrogen during the year of establishment. Falloon (^2) also indicated that a small amount of nitrogen was beneficial at planting time. Purvis (36) stated that small amounts of nitrogen may inter­ fere with the nitrogen fixing bacteria and that it takes 18 100 pounds of nitrogen per acre to offset this loss. (5) Blaser (6) and Dobson and Woodhouse (11) also recommended a- bout 20 pounds of nitrogen per acre during the first year of establishing alfalfa. Attoe and Peterson (2), Peterson (32), and Wedin et al (54) did not use a fertilizer containing nitrogen in their experiments but stressed the point of adding high rates of lime, phosphorus and potassium which would contribute to a very favorable environment for root nodule bacteria that might eliminate the need for nitrogen. III. METHODS OF EXPERIMENTATION Soil Pot Studies in the Greenhouse In the fall of 1954, three soils, a Brookston clay loam.from the Ferden farm, a Miami loam from the University farm and an Oshtemo loamy sand from the Rose Lake Experi­ ment Station were collected, dried, brought to the green­ house and weighed into two-gallon glazed pots. For the Miami and the Osthemo, 9000 grams were necessary to fill the pots up to within oneinch of the top but for Brookston only 8000 grams were needed. the This left an ade­ quate space for watering to avoid losing any soil. Several soil samples were taken and composited for chemical analysis. The analysis of the above soils toget­ her with three additional soils; a Fox sandy loam from the Kellogg farm, a Conover loam and a Hillsdale loam from the University farm which were used in 1955 are reported in table 1. TABLE 1.- Composition of soils used in the greenhouse study Soil type Miami loam Brookston clay loam Oshtemo loamy sand Conover loam Hillsdale loam Fox sandy loam pH % 0. M. 6.3 6.9 6.8 7.2 6.4 6.6 2.200 4.903 0.741 3.841 2.206 1.155 19 %N 0.125 0.200 0.043 0.157 0.113 0.077 P lbs/A 16 78 9 72 50 50 K lbs/A 87 120 56 64 150 200 20 The pH was measured with the glass electrode* Organic matter determinations were made by analyzing for total car­ bon and multiplying by 1.724 (34). Total nitrogen was de­ termined by the KJeldahl method (31) and phosphorus and po­ tassium were analyzed by the Spurway method (41). The Miami soil was slightly acid and was limed at the rate of two tons per acre using a technical grade calcium carbonate. The Oshtemo was fertilized at the rate of 400 pounds per acre, the Miami received 300 pounds per acre and the Brookston 200 pounds per acre of an 0-20-20. This was according to the current fertilizer recommendations for supplying adequate amounts of phosphorus and potassium (12). The following year the Fox, Hillsdale, and Conover soils were used and were fertilized at the following rate? the Fox and Hillsdale received 150 pounds per acre of an 0-20-20 and the Conover 200 pounds per acre. Ammonium sulfate was used both years as the source of nitrogen and applied at the rate of 0, 20, 40, 80 and 160 pounds of elemental nitrogen per acre. All fertilizer ma­ terials were banded using the inverted pot method, placing the fertilizer two inches below and one inch to the side of the seed. All treatments were replicated four times. Canada G-rimm alfalfa seed which had been properly in­ oculated was planted in all six soils. A few days after emergence the plants were thinned to fifteen plants per pot. Three cuttings were taken from each planting for yields and protein content and soil samples were taken at the end of the experiment. Each yield sample was analyzed for total nitrogen the first year but the following year the replicates were bulked and analyses were carried out in duplicate. Methods Used in Field Studies Two types of field studies were carried out. One in­ cluded rates of nitrogen with various seeding dates, de­ pending upon the companion crop, and the other included different forms of nitrogen at a constant rate on alfalfa. For the first type, three locations were obtained. These were a Fox sandy loam soil on the W. K. Kellogg farm, Battle Greek, Michigan; a Brookston clay loam soil on the Lee Ferden farm at Chesaning, Michigan; and a Hillsdale loam soil on the University farm at East Lansing, Michigan. These three soils were the same as those used in the green­ house study. The treatments were the same as in the greenhouse study except the high rate of nitrogen was omitted, only the 0, 2Q 40 and 80 pounds of nitrogen were used. All treatments were replicated four times and were set up either as a ran­ domized block or split plot design. Four plantings were made at each of the three locations. The first planting of alfalfa consisted of a random­ ized block with the four rates of nitrogen, and four repli­ cations with oats as the companion crop at the Kellogg farm and the University farm and barley as the companion crop at the Ferden farm. All three locations were planted during the month of April, 1955. The second planting was made in August 1955 at each location. This block was also a randomized block design with four rates of nitrogen, four replicates and alfalfa seeded alone. The third and fourth plantings were made in September 1955 and consisted of two blocks of wheat each with four levels of nitrogen and four replications. At each of the three locations alfalfa was seeded in the wheat in the fall in one block and overseeded in the wheat in the spring of 1956 in the other block and at this time each plot of wheat and alfalfa was split, one half receiving 20 pounds of ni­ trogen as a topdressing. All plots at each location received a blanket applica­ tion of phosphorus and potassium by applying 500 pounds of an 0-20-20 fertilizer before making the initial planting. All grain crops were harvested for yield. content and test weights were also measured. Protein Yields were taken from all hay plots from one to four cuttings depend­ ing upon the planting date and all samples were analyzed for protein. The second type of field study was nitrogen carriers which was carried out in 1957 and consisted of a topdressing of alfalfa at four additional locations throughout the state. In this study thirty pounds of elemental nitrogen was apolied in the form of ammonium sulfate, ammonium nitrate and urea to compare with a check. Each treatment was repli­ £3 cated five times at each location. Soil samples were taken and analyzed for pH, phosphorus and potassium as shown in table 2. Two cuttings were taken for yield and protein co nt ent. TA3L2 2. - The location , soil type and chemical analysis of soils used in sourc es of nitrogen study. oH Pounds oer acre Phosphorus Potassium Sur­ face Sub­ soil Sur­ face Sub­ soil Sur­ face Oshtemo loamy sand 6.8 6.1 28 20 233 62 Calhoun Ockley sandy loam 5.8 5.6 53 42 178 62 Jackson Belfontaine sandy loam 6.8 6.2 39 35 67 21 6.4 6.2 72 22 275 137 County Barry Lapeer Soil Type Conover loam Sub­ soil IV. RESULTS AND DISCUSSION Soil Pot Studies in The Greenhouse The application of nitrogen to alfalfa in the green­ house gave varying hut interesting results. Nitrogen in­ fluenced the yield of alfalfa differently on each soil studied. Statistical analyses indicate a highly significant difference in yield between the nitrogen treatments applied to the Oshtemo loamy sand and a significant difference for the Miami loam soil. Figure 1 and table 3 show that twenty pounds of nitrogen increased the yield of alfalfa but forty pounds of nitrogen gave a greater percent increase. The additional nitrogen applied gave no substantial increase in yields and did not bring about any detrimental effects. The Conover soil responded only slightly to the appli­ cation of nitrogen. The highest yields were obtained with the highest rate of nitrogen as on the Oshtemo, but this increase over the check was not significant. The highest yields were obtained on the Hillsdale and Miami at the eighty pound rate and then dropped with the higher rates of nitrogen. dale soil. This increase was not significant on the Hills­ The results obtained on the Fox and Brookston soils were the most erratic of all. The highest yield on the Brookston was obtained from the 160 pound rate and was 24 25 Brookston o rH -H 03 a SH o hO r s o a •H co a> Ci +-5 £ aj O Sh aO o as 10d U3d SWVH9 a> 26 TABL il 3.- The effect of rates of application of ammonium sulfate on the mean yield of alfalfa, grown in the greenhouse in 1955 and 1956, Pounds of nitrogen per a c r e _____ 20 40 80 160 Grams per pot Brookston clay loam 1 9.72 10.52 11.92 10.54 10.68 2 11.95 13 .65 10.76 12.00 11.81 3 11.33 13.13 12.26 10.88 11.81 Average 10.72 11.45 11.00 12.90 11.58 LSD (.05) 3.49 (.01) 4.67 Cutting 0 Miami loam 1 5.85 2 9.33 9.24 3 ■ 8.14 Average LSD (.05) 2.00 (.01) 2.67 8.07 11.00 10.79 9.95 8.72 10.99 10.95 10.22 7.84 9.20 9.97 9.00 7.64 7.66 9.49 8.26 8.64 6.67 9.49 8.27 8.85 7.53 9.58 8.65 5.51 11.60 16.15 11.09 4. 66 12.20 15.60 10.82 4.97 12.50 16.86 11.44 6.89 7.50 11.60 8.66 6 *22 7.70 11.15 8.36 6.32 7.80 11.99 8.70 5.04 12.17 13.26 10.16 5.13 12.30 13.15 10.19 5.24 12.07 15.99 11.10 5.78 12.40 13.09 10.42 9.40 9 .81 10.04 10.19 6.64 9.16 8.62 8.14 Oshtemo loamy sand 6.31 1 5.94 2 3 8.56 6.94 Average LSD (.05) 1.47 (.01) 1.97 6.46 6.11 9.28 7.28 Fox sandy loam 1 2 3 Average LSD (.05) 1.92 (.01) 5.46 12.50 16.51 11.49 2. 56 4.89 12.40 15.49 10.93 Conover loam 6.05 1 7.30 2 11.20 3 8.18 average 3. 56 (.01) LSD (.05) 2.67 6.05 6.90 11.88 8.28 Hillsdale loam 4.25 1 11.97 2 11.98 3 9.40 Average LSD (.05) 1.86 (.01) 2.48 9.19 Average of 6 soils 27 still increasing while the Fox was giving a yield somewhat lower than the check. An interaction between cuttings and treatments was ob­ tained only on the Fox sandy loam soil. Guttings were high­ ly significant on all soils in the study except for the Brookston clay loam. The yields are given for each soil by cuttings in tables 1, 3, 5, 7, 9, and 11 in the appendix. Table 3 also shows that while there was no large in­ crease in yield brought about by the addition of large amounts of nitrogen, a small but consistent increase is shown for the average of the six soils. Analysis of the data given in table 4 shows that there is no significant change in the percent protein found in alfalfa from the addition of large amounts of nitrogen. It is of interest to note here the small but steady increase which occurred over the range of nitrogen treatments, same as that found in the yield data. the A highly significant difference in the percent protein was found among soils, cuttings and in the interaction of cuttings times nitrogen treatments. The Oshtemo loamy sand produced alfalfa with a lower percent protein than any of the other studied. produced alfalfa with the high­ The Hillsdale soil five soils est percent protein followed by the Fox, Brookston, Miami and Conover. The first cutting produced the highest per­ cent protein and decreased progressively with the second and third cuttings. The interaction between cuttings and nitrogen treat- 26 TABLE 4.- The effect of rates of application of ammonium sulfate on the mean percent protein in alfalfa grown in the greenhouse in 1955 and 1956. Gutting 0 Pounds of nitrogen oer acre 20 160 40 80 Percent prot ein Brookston clay loam 1 2 3 Average 19.86* 18.93 18.20 19.00 20.90 18.74 18.03 19.22 19.09 17.10 17.67 17.95 19.86 17.65 18.49 18.67 19.71 16.02 16.50 17.41 18.05 15.40 17.30 16.92 19.38 17.96 16.98 18.11 21.14 19.40 17.32 19.29 15. 51 17.23 15.29 16.01 15.46 17.23 15.51 16.07 17.21 17.89 15.77 16.96 22.25 19.80 16.17 19.41 22.44 17.90 15.91 18.75 23 .44 16.90 16.17 18.84 20.44 19.40 16.17 18.67 21.56 17.80 15.02 18.13 20.00 18.90 16.88 18.59 19.88 20.30 16.70 18.96 17.99 21.33 19.70 17.50 19.51 18.21 23.31 18.80 17.50 19.87 18.49 Miami loam 1 2 3 Average 18.87 17.49 17.74 18.03 19.28 19.11 17.41 18.60 Oshtemo loamy sand 1 2 3 Average 15.89 15.92 14.85 15.55 15.36 17.25 15.18 15.93 Fox sandy loam 1 2 3 Average 19.06 19.50 16.08 18.21 19.88 17.80 17.23 18.30 Gonover loam 1 2 3 Average 18.75 17.70 15.02 17.16 20.12 18.70 14.58 17.80 Hillsdale loam 17.25 1 19.90 2 15.91 3 17.69 Average 17.61 Average of 6 soils LSD (.05) 1.84 (.01)2.44 * Kjeldahl x 6.25 16.94 19.40 16.79 17.71 17.93 2b rnent points out that some of the nitrogen treatments gave an increasingly higher percent protein for the first cut­ ting while the second and third showed an increase for the first increment of nitrogen and a decrease for the second increment of nitrogen* Cutting two then showed a progress­ ive decrease while cutting three gave a progressive increase in the protein content. The percent protein for soils by cuttings are given in tables 2, 4, 6, 8, 10, and 12 in the appendix. In table 5 the amount of total protein was calculated from the average percent protein given in table 4 and the mean yield data given in table 3. An analysis of these data shows significance for both soils and nitrogen applied. The ranking of total amount of protein produced from all six soils was parallel to the rate of nitrogen applied. After the third cutting of alfalfa was removed, samples were taken and analyzed for total nitrogen. data are shown in table 6. soil These Using the data obtained thus far, a nitrogen balance was calculated for the first, third and fifth rates of nitrogen applied, but no real facts were elucidated. However, a general understanding of the vari­ ability as shown in figure 1 was pointed out. 3C TABLE 5.- The effect of rates of application of ammonium sulfate on the total protein produced from four pots and three cuttings of alfalfa. ooil type 0 Pounds of nitrogen per acre 20 160 80 40 G-rams protein per pot Brookston clay loam 25.06* 26.72 23.10 25.66 26 .93 Miami loam 17.65 18.17 20.20 22.21 20.82 Oshtemo loamy sand 12.97 13.92 15.68 15.95 17.62 Fox sandy loam 25.11 24.06 25.81 24.41 25.91 Conover loam 16. 93 17.68 19.^3 18.17 19.44 Hillsdale loam 20.30 21.60 23.20 66 .03 24.85 Average 19.67 20.36 21.27 22.07 22.60 LSD (.05) 1.76 (.01) 2.34 * Yield times the average protein content. TABL2 6.- The effect of rates of application of ammonium sulfate on the residual percent nitrogen found in the soils after the removal of three cuttings of alfalfa. 0 Soil type Pounds of nitrogen per acre 40 160 80 20 Percent nitrogen Brookston clay loam 0.187* 0.191 0.192 0 .196 0.212 Miami loam 0.111 0.116 0.111 0.102 0.107 Oshtemo loamy sand 0 *035 0.034 0.040 0.034: 0.038 Fox sandy loam 0.077 0.078 0.080 0.077 0 .069 Conover loam 0.134 0.137 0.150 0.145 0.150 Hillsdale loam 0.098 0.103 0.109 0.113 0.125 Average 0.107 0.110 0.114 0.111 0.117 LSD for treatment (.05) 0.0058 (.01) 0.0079 * Total nitrogen by Kjeldahl analysis 51 Results Obtained From Field Studies Weather conditions in the early part of the 1955 grow­ ing season were very mild and all crops planted in this study germinated soon after planting and grew very rapidly* The yield of oats (table 7) grown on a Fox sandy loam at the Kellogg Farm ranged from 40.6 bushels to 73.5 bushels per acre with averages by treatments ranging from 4*3.8 bushels with no nitrogen fertilizer up to 59.8 bushels with 80 pounds of nitrogen. Twenty pounds of nitrogen produced 56.3 bushels of oats per acre which was highly significant over the zero nitrogen plots. The amount of weeds in the plots at har­ vest time was proportional to the amount of nitrogen applied. It was thought that the high rates of nitrogen might weaken the stems and cause lodging; however, no lodging occurred under the prevailing weather conditions of these plots. The protein content (table 6) of the grain was in­ creased from 12,63 percent with no nitrogen to 15,60 per­ cent with 80 pounds of nitrogen. The yields of alfalfa harvested from these plots in 1956 with no additional fertilizer applied ranged from 1.85 tons to 2.20 tons per acre for two cuttings (table 9). The 20 pound rate of nitrogen produced a yield that was significant over the 40 pound rate but was not significant over the other two nitrogen treatments. The first cutting was bn the average two times more than the second cutting probably because of droughty conditions that existed on TABLE 7*- The effect of rates of application of ammonium sulfate on the yield of grain harvested in 1955* Replication Pounds of nitrogen per acre________ 20 40 60 0 Bushels per acre Oats, Fox sandy loam A 40.6 ol ,0 62.5 6 5.6 B 42.4 54.7 53.1 46.9 G 45.3 59 c3 54.7 73.5 D 46.9 50.0 54.7 53.1 Average 43.8 56.3 56.3 09 .ci LSD (.01) 10.1 bushels Oats, Hillsdale loam A 70.3 57.8 51.3 63.0 B 72.9 66 .3 57.8 52 .5 C 86.5 78.0 54.5 62.2 D 65.3 70.5 63.C uQ.7 Average 73.8 68.2 56.7 54.6 LSD not significant Barley, Brookston clay loam A 45.6 60.3 63.0 66.6 B 47.2 55.3 56.9 58.4 G 42.3 55.0 56.0 50.0 D 40.4 49.6 50.8 49 .6 Average 4 3 .u 55.1 56.7 56.2 LSD (.01) 6.5 bushels TABLE 8.- The effect of rates of application, of ammonium sulfate on the percent protein of grain harvested in 1955. Replication 0 Pounds of nitrogen per acre_______ 20 40 80 Percent protein Oats, Fox sandy loam A 12.61* 13.52 14.14 15.02 B 12.50 14.89 15.47 17.01 G 12.24 13.26 14.49 14.85 D 12.95 14.67 15.47 15. 53 Average 12.63 14.09 14.89 15.60 LSD (.05) 0.78 (.01) 1.13 Oats, Hillsdale loam A 10.87 12.59 13.17 14.36 B 11.27 13.70 14 e89 13.92 C 12.59 12.59 14.23 13.92 D 13.61 12.55 13.92 14.49 Average 12.09 12.86 14.05 14.17 LSD (.05) 1.48 (.01) 2.13 Barley, Brookston c lay loam A 9.90 10.65 11.71 12.90 B 10.52 10.69 11.53 11.93 C 10.60 11.09 11.14 11.97 D 10 .4o 10.43 11.44 12.06 Average 10.36 10.72 11.46 12.22 LSD (.05) 0.59 (.01) 0.85 * Kjeldahl x 6.25 34 TABLE 9 t— The effect of rates of application of ammonium sulfate on the mean yield of alfalfa. Gutting Year 0 Pounds of nitrogen per acre_____ 20 40 80 Tons per acre Alfalfa after oats, Fox sandy loam 1 2 Total 1 1056 1S56 1S56 1957* 1.35 0.63 1.98 1.95 1.49 0.70 2.19 1.99 1.25 0.57 1.B2 1.78 1.35 0.69 2.04 2.03 Alfalfa after oats, Hillsdale loam 1 2 Total 1 2 Total lb 56 lb5S lb56 1957 1957 1957 1.94 1.34 3.28 3.17 1.77 4.94 1. 95 1.40 3.35 2 .30 1.71 4.01 1.97 1.21 3,18 2, 66 1.57 4.23 1*99 1.23 3.22 2.56 1.59 4.15 A1 falfa alone, Hillsdale loam 1 2 Total 1 2 Total 1956 1956 1956 1957 1957 1957 1.25 0.71 1.96 2.22 1.50 3.72 1.05 0.72 1.77 2.24 1.63 3.87 1.19 0.72 1.91 2.33 1.57 3.90 1.11 0.71 1.82 2.23 1.53 3.76 Alfalfa after barley , Brookston clay loam 1 2 Total 1 2 Total 1956 1956 1956 1957 1957 1957 1.65 1.53 3.38 2.32 0.96 3.28 1.70 1.54 3.24 2 *44 1.22 3 .66 1.47 1.63 3.10 2.59 1.02 3 .61 1.31 1. 48 2.79 2.32 0.98 3.30 Alfalfa alone, Br ookston clay loam 1 2 Tota I 1 2 Total 1956 1956 1956 1957 1957 1957 1.22 1.36 2.58 2.16 0.91 3.07 *one cutting only 1.52 1.06 2.58 1.93 1.08 3.01 1.70 1.48 3.18 2.22 1.04 3.26 1.53 1.37 2.90 2.07 1.03 3.10 co this sandy soil* The protein content (tahle 10) was much higher for the second cutting since some species of weeds were removed during the first cutting leaving a better stand of alfalfa. Only the first cutting was taken for yields and chemi­ cal analyses during 1057 and by this time the differences in yield were very small giving no significance by statisti­ cal analysis. The protein content was the same as the check plot for 1056 but the rest of the treatments showed a slight decrease (table 11). Poor stands were obtained on the alfalfa plots seeded in August on the Fox sandy loam soil in 1955 and the plots were plowed and seeded to spring oats in 1956 with no fer­ tilizer applied. After the oats were combined another planting of alfalfa was made in August of 1956. No addi­ tional potassium or phosphorus was applied at planting time but the same rates of nitrogen were repeated as a crop of oats had been removed since the plots were last fertilized. Poor stands were obtained again and this location was aban­ doned as far as the August planting was concerned due to insufficient soil moisture at this time of the year. At the University farm an excellent stand of oats and alfalfa was obtained on all plots seeded during the month of April in 1955 on a Hillsdale loam. Apparent differences from the variable rates of nitrogen could be observed up to the 8th of July when a heavy windstorm and rain passed through the area. The following day the plots were rated as to damage by lodging as some, moderate, and severe. The plots receiving 80 pounds of nitrogen were classified as severe lodging in three of the four replications, the plots receiving 40 pounds ol‘ nitrogen were classified as moderate lodging in two replications and as some lodging in one rep­ lication. The plots receiving 20 pounds of nitrogen did not appear to be damaged any more than the check plots, but at harvest time these yields were much lower (table 7). In spite of reduced yields these rates of nitrogen gave a pro­ gressive increase in protein content (table 8) which indi­ cates a higher quality grain for feeding purposes. Four cuttings of alfalfa hay were taken off the plots following oats on the Hillsdale loam soil at the University farm, two cuttings in 1956 and two cuttings in 1957. The yields of second cutting for each year were lower than the first cutting but not quite as low in proportion to the yields at the Kellogg farm. No significant Increases were found for either year; however, all plots receiving nitro­ gen fertilizer gave a lower yield than the check plots for the first cutting of 1957 (table 9). The greatest variation in protein content in these four cuttings was found to be in the first cutting of 1956 (table 10). Smaller increases were found in the other three cuttings and the second cut­ ting of each year was higher in protein than the first cut­ ting, The August seeding at the University farm on the Hills­ dale loam soil was far superior to the seeding made at the •:? TABLE 10.~ The effect of rates of ajjplication of ammonium sulfate applied in 1955 on the percent protein found in alfalfa hay harvested in 1956. Pounds of nitrogen per acre ting Repi icat ion 0 80 20 4:0 Percent protein Alfalfa after oats, Fox sandy loam 1 2 A B Average A B Average 13 .60 14.12 13.86 16.00 16 .40 16. 20 12 .4 5 13.78 13.12 16. 50 16.50 16.50 14.12 13.78 13.95 16.95 17.35 17.15 15.03 15.03 15.03 16. 50 16.50 16.50 Alfalfa after oats, Hillsdale loam 1 2 A B Average A B Average 11.05 16.18 13.62 19.21 19.89 19.55 11.32 11.94 11.63 19.21 19.79 19.50 13.54 12.91 13.23 17.46 18.82 18.14 16 .18 14.85 15.52 19.50 20.56 20.03 Alfalfa seeded alone , Hillsdale loam 1 2 A B Average A B Average 16.34 16.18 16.26 18.25 18.84 18.55 16.35 16.88 16.62 19.32 19.61 19.47 17.15 15.03 16.09 19.23 16.64 18.94 16.09 15.03 15.56 17.28 16.80 17.04 Alfalfa after barley, Brookston clay loam 1 2 A B Average A B Average 13.26 14.76 14.01 17.67 16 .99 17.33 14.41 13.08 13.75 17.96 17.66 17.91 14.41 12.11 13.26 19.42 19.42 19.42 15.29 15.65 15.47 17.8? 17.38 17.63 Alfalfa seeded alone, Brookston clay loam 1 z A B Average A 3 Average 14.41 14.76 14.59 20 .49 19.90 20.20 15.82 17.50 16.66 22.43 21.27 21.85 13.52 16.88 15.20 21.36 21.65 21.50 18.83 16.18 17.50 19.52 19.03 19.28 36 TABLE 11.- The effect of rates of application of ammonium sulfate applied in 1955 on the percent protein found in alfalfa hay harvested in 1957. Cutting Heplicat ion Pounds of nitrnp-fin nor acre 0 20 80 40 Percent protein Alfalfa after oats*, Fox sandy loam 1 A B Average 13.77 13.94 13.66 13.32 12.96 13.14 12.78 12.96 12.87 12.87 13.32 13.10 Alfalfa after oats, Hillsdale loam 1 2 A B Average A B Average 15.02 13.77 14.40 16.27 17.52 16 .90 13.14 14.21 13.68 18.77 19.49 19.13 13.05 13.77 13.41 16.51 18.33 18.42 15.20 14. 66 14.93 17.70 17.88 17.79 Alfalfa seeded alone, Hillsdale loam 1 2 A B Average A B Average 12 .96 12.60 12.78 19.44 20.65 20.05 14.30 13.95 14.13 18.86 19.40 19.13 14 .30 14.30 14.30 19.49 20.03 19.76 12.78 12.43 12.60 19.31 19.67 19.49 Alfalfa after barley, Brookston clay loam 1 2 A B Average A B Average 12.61 11.89 12.25 17.34 17.16 17.25 15.56 15.64 15.60 16.45 16.63 lc.54 12.96 13.50 13.23 15.82 16.72 16.27 15.02 13.95 14.49 16 *45 16.09 16.27 Alfalfa seeded alone, Brookston clay loam 1 2 * A B Average A 3 Average First cutting only, 15.20 14.48 14.84 15. 56 15.02 15.29 13.59 14.46 14.04 15.91 14. 66 15.29 15.20 15. 56 15.38 15.20 13.95 14.58 13.86 13.50 13 .68 13 .68 13.95 13.82 Kellogg farm on the Fox sandy loam soil. Four cuttings were taken here also and smaller yields were obtained in 1^56 than in 1957, indicating that the plants were not as well established when seeded in August as compared to the spring planting (table 9). There was little difference in the yields due to treatments for either year but again the second cutting was much lower than the first. The protein content of the second cutting of 1957 (table 11) was con­ siderably higher than the first cutting following the same pattern as the protein content of 1956 (table 10). Some of these differences can be attributed to the harvest sam­ pling dates. At the Ferden farm where barley was planted as the companion crop, on a Brookston clay loam, a significant yield response for the barley was found due to nitrogen (table 7). Twenty pounds of nitrogen gave the largest per­ cent increase. nitrogen. Little response was found from additional The percent protein (table 8) of the grain pro­ duced a linear effect ranging from 10.36 percent with no nitrogen to 12.22 percent with 80 pounds of nitrogen per acre • Four cuttings of hay were removed from these plots dur­ ing the next two years with no additional fertilizer. Yields are given in table 9. Here again there was no dif­ ference in yield due to treatments. The yields of the first and second cutting in 1956 were about equal while in 1957 the first cutting was about two times greater than the <±0 second. The protein content (table 10) shows a consider­ able increase due to nitrogen treatments for the first cut­ ting in 1956 and a slight increase for two of the nitrogen rates in the second cutting in 1956. In 1957 the protein content was more or less constant for all nitrogen treatments as shown in table 11. Soil moisture was adequate for germination on a Brook­ ston clay loam at the Ferden farm in the fall of 1955 and an excellent stand was obtained from the August seeding. The yields are given in table 9 for four cuttings taken from these plots in 1956 and 1957. No significance was shown for treatments in either of the cuttings. The two cuttings taken in 1956 were of about equal size while the first cutting in 1957 was about two times greater than the second cutting which was the same for the alfalfa following barley at this location. There was an increase in protein content in lw56 (table 10) for both cuttings due to nitro­ gen treatments while in 1957 (table 11) there was a decline in the percent protein. The hay yield for each of these plantings for the var­ ious soil types are given in tables 15, 14, 15, 16 and 17 of the appendix. Wheat as a. Companion Crop Wheat yields in general did not vary much between lo­ cations regardless of nitrogen fertilizer treatments or ni­ trogen topdressing. Nitrogen treatments gave a significant increase in yields in four of the six blocks while nitrogen 4l topdressing gave a significant increase in only two of the six blocks indicating that in most cases there was an ade­ quate supply of nitrogen (tables 12, 13, 14). Severe lodg­ ing was not encountered until 80 to 100 pounds of nitrogen had been applied either at planting time or at planting time plus topdressing. At the Kellogg farm on a Fox sandy loam both nitrogen treatment and nitrogen topdressing gave a significant in­ crease in yield for the block of wheat that was fall plan­ ted and over seeded with alfalfa and topdressed with nitro­ gen the following spring. The other block of wheat, which was fall planted with alfalfa and topdressed in the spring, did not respond to either (table 12). The protein content (table 15) ranged from 9.48 to 14*87 percent with in treat­ ments and the average for topdressing ranged from 9.63 to 14.68 percent. The test weight shown in table 18 was not seriously affected even with the addition of 100 pounds of nitrogen in any of the six blocks of wheat. Only the nitrogen treatments gave a significant increase in yield in one block of wheat on the Hillsdale loam soil (table 13). Topdressing with 20 pounds of nitrogen gave a good increase over the check in both blocks but reduced the yields of the treatments where some nitrogen had been ap­ plied the previous fall. The percent protein in the grain produced on these plots falls in a very narrow range as shown in table 16. Additional nitrogen gave a significant increase In the TABLE 12.- The effect of rates of application of ammonium sulfate on the yield of wheat on a Fox sandy loam soil in 1956. Replication 0 Pounds of nitrogen per acre______ 20 40 80 Bushels per acre Wheat and alfalfa fall planted A B C D 31.4 26.7 29.0 37.5 41.0 30.2 31.5 37.5 36.5 20.6 43.5 42.4 37.5 32.6 48.3 14.5 Average 31.2 35.0 35.8 33.2 Topdressed in the spring A B C D 27.8 26.7 35.0 41.0 29.0 31.5 38.7 35.0 32.6 24.2 35.0 37.5 33.5 32.6 33.5 19.3 Average 32.6 33.6 32.3 29.7 LSD for treatment (.05) not significant. ing (.05) not significant. LSD for topdress­ Wheat over seeded with alfalfa in the spring A B C D 24.2 35.0 35.5 29.0 41.2 36.4 43.5 38.6 41.3 41.0 47.2 41.0 40.0 38.8 44.8 44.8 Average 30.9 39.9 42.6 42.1 Topdressed in the spring A B C D 37.5 38.6 41.0 41.0 43.5 41.0 43.5 41.0 40.0 38.7 42.4 40.0 38.7 41.0 48.8 41.0 Average 39.5 42.3 40.3 42.4 LSD for treatment (.05) 5.4 bushels. (.05) 3.7 bushels. LSD for topdressing 43 TABLE 13.- The effect of rates of application of ammonium sulfate on the yield of wheat on a Hillsdale loam soil in 1956* Replication o Pounds of nitrogen per acre 20 40 __ 60 Bushels per acre Wheat and alfalfa fall planted A B C D 37.9 40.8 44.7 42.3 43.0 49.2 55.0 51.7 45.6 52.0 53.0 46.0 35.0 40.2 39.7 45.3 Average 41.4 49.7 49.2 40.0 Topdressed in the spring A B C D 45.3 49.3 47.0 45.0 45,3 45.0 34.0 43.3 32.0 43.0 40.2 47.3 44.0 32.0 41.3 42.0 Average 46.7 41.9 40.6 39.8 &D for treatment (.05) 5.7 bu. >t significant. LSD for topdressing (.05) Wheat overseeded with alfalfa in the spring D 22.0 43.0 33.6 41.0 39.0 39.7 26.3 51.0 35.5 52.7 26.7 39.4 30.2 37.4 26.0 52.7 Average 35.1 39.0 38.6 36.6 A B G Topdressed in the spring D 30.5 29.0 38.7 48.8 19.8 41.0 48.4 35.0 20.6 39.7 25.5 48.3 28.7 28.2 17.2 43.0 Average 36.8 36.0 33.5 29.3 A B 0 LSD for treatment (.05} not significant. ing not significant (.05) LSD for topdress­ 44 TABLE 14,- The effect of rates of application of ammonium sulfate on the yield of wheat on a Brookston clay loam soil in 1956, Replication O Pounds of nitrogen per acre 20 40 80 Bushels per acre Wheat and alfalfa fall planted A B C D 35,? 36,7 38.4 34.4 34,4 37.8 38.7 37.8 39.3 42.0 43.3 43.5 42.0 49.0 43.7 37.8 Average 36,3 37.2 42.0 43.1 Topdressed in the spring D 44.3 43.5 38.2 44.3 39.5 46.6 45.5 47.2 42.2 46.5 43.3 47.0 43.7 43.0 33.0 52.0 Average 42.6 44.7 44.6 42.9 A B C LSD for treatment (.05) 4.7 bushels (.05) 5.4 bushels. LSD for topdressing Wheat overseeded with alfalfa in the spring D 34.4 30.8 37.4 30.2 39.2 41.2 36.8 36.6 42.2 40.8 40.8 37.1 41.2 40.0 40.8 43.0 Average 33.2 38.5 40.2 41.3 A B G Topdressed in the spring D 36.2 41.5 30.7 38.7 43.0 46.6 40.8 35.7 39.6 41.8 35.2 35.6 37.8 41.0 36.6 40.8 Average 36.8 41.5 38.0 39.1 A B C LSD for treatment (.05) 4.6 bushels. (.05) not significant. LSD for topdressing *5 TABLE 15.- The effect of rates of application of ammonium sulfate on the percent protein of wheat grown on a Fox sandy loam soil in 1956. Replication o Pounds of nitrogen per acre 20 40 80 Percent protein Wheat and alfalfa fall planted A 9.82 10.55 12.49 14.05 B 10.69 10.55 12.73 14.87 Average 10.26 10.55 12.61 14.46 Topdressed in the spring A 10.69 12.64 13.60 14.68 B 10.79 12.64 13.90 14.68 Average 10.74 12.64 13.75 14.68 Wheat overseeded with alfalfa in the spring A 9.48 10.59 11.91 11.66 B 9.77 10.30 11.62 11.52 Average 9.63 10.45 11.77 11.59 Topdressed in the spring A 11.23 13.22 14.34 14.58 B 11.52 12.88 15.02 13.95 Average 11.38 13.05 14.68 14.27 46 TABLE 16.- The effect of rates of application of ammonium sulfate on the percent protein of wheat grown on a Hillsdale loam soil in 1956. Replication 0 Pounds of nitrogen oer acre_____ 20 40 80 Percent protein Wheat and alfalfa fall planted A 11.52 11.57 11.18 12.15 B 11.37 11.42 11.90 11.91 Average 11.45 11.50 11.54 12.02 Topdressed in the spring A 12.05 10.59 12.64 12.73 B 11.71 12.30 12.15 12.83 Average 11.88 11.45 12.40 12.78 Wheat overseeded with alfalfa in the spring A 12.10 12.93 12.64 13.85 B 11.96 12.59 12.44 13.61 Average 12.03 12.76 12.54 13.73 Topdressed in the spring A 12.98 13.22 13.17 13.32 B 13.27 13.36 12.88 13.51 Average 13 .13 13.29 13.03 13.42 47 TABLE 17.- The effect of rates of application of ammonium sulfate on the percent protein of wheat grown on a Brookston clay loam soil in 1956. Replication ______Pounds of nitrogen per acre 0 20 40 80 Percent protein Wheat and alfalfa fall planted A 12.10 10.94 10.64 11.42 B 11.23 10.84 10.74 11.13 Average 11.67 10.89 10.69 11.28 Topdressed in the spring A 11.08 11.37 11.42 11.32 B 12.05 11.47 11.32 11.38 Average 11.57 11.42 11.37 11.35 Wheat. overseeded with alfalfa in the spring A 11.08 11.23 10.89 11.23 B 11.13 11.13 11.37 12.01 Average 11.11 11.18 11.13 11.62 Topdressed in the spring A 11.62 11.37 11.91 11.62 B 11.28 11.86 11.76 11.62 Average 11.45 11.62 11.84 11.62 46 TAB LE 18.- The effect of rates of application of ammonium sulfate on the test weight of wheat grown on three soils in 1956* Date of application Pounds of nitrogen per acre______ 20 40 60 80 100 0 Fox sandy loam Fall 55.4* Fall and spring 56.2 Fall Fall and spring 57.0 56.5 55.9 56.5 57.1 56.5 56.2 57.4 57.5 56.6 56.6 56.4 57.2 56.0 Hillsdale loam 56.8 Fall Fall and spring 55.2 Fall Fall and spring 57.4 57.2 57.0 57.2 56.4 55.9 55.8 55.3 57.4 56.9 56.8 55.6 55.9 55.8 Brookston clay loam 55.7 Fall Fall and spring 54.6 Fall Fall and spring * 56.0 55.0 55.9 55.8 55.4 55.3 55.0 55.0 Average of four replications 55.7 55.3 56.1 55.6 55.8 55.1 49 yields of wheat on both blocks on the Brookston clay loam soil (table 14). Nitrogen topdressing was beneficial on the wheat where alfalfa was interplanted in the fall but did not respond significantly in the block where the alfal­ fa was planted in the spring. The wheat yields in each block indicate that about forty pounds of nitrogen was sufficient for satisfactory production on that soil. The percent protein (table 17) also shows consistency indicating no luxury consumption or storage in the grain. The yields of alfalfa following wheat on the Fox sandy loam with no additional fertilizer applied are given in table 19. Only one cutting was taken in 1957 and a signif­ icance was obtained only with the nitrogen topdressing when the alfalfa was fall planted with the wheat. The yields of alfalfa when spring planted in wheat were so erratic giving a large error term and therefore were not significant. The percent protein (table 22) was slightly higher for the fall planted alfalfa that was topdressed in the spring. The ni­ trogen treatments increased the protein content in the spring planted alfalfa but then decreased when additional nitrogen was applied as a topdressing to the wheat at the time of seeding of alfalfa. Alfalfa fall planted in wheat on the Brookston clay loam in 1955 did not respond to nitrogen treatments or ni­ trogen topdressing in the spring of 1956. The yields for two cuttings in 1957 given in table 20 shows a significant decrease resulting from additional nitrogen applied as a 50 T ABLE 19.- The effect of rates of application of ammonium sulfate on the yield of alfalfa following wheat on a Fox sandy loam soil in 1957. Replication _______Pounds of nitrogen per acre______ 0 20 40 80 Tons per acre Alfalfa fall planted in wheat A B G D Average 1.57* 1.62 1.36 1.25 1.45 1.50 2.13 1.28 1.38 1.57 1.63 1.77 1.19 1.33 1.48 1.03 1.19 1.47 1.17 1.22 Wheat topdressed in the spring A 1.73 1.52 B 1.18 1.60 0 1.38 1.39 D 1.75 1.23 Average 1.51 1.44 LSD for treatment (.05) not significant. ing (.05) .25 tons. 1.12 1.31 1.65 1.46 1.58 1.23 1.18 1.42 1.38 1.36 LSD for topdress­ Alfalfa spring planted in wheat A B G D Average 1.06 1.52 1.82 1.07 1.37 1.50 1.60 1.44 1.42 1.49 1.19 1.25 0.73 1.42 1.15 1.02 1.20 1.59 1.50 1.33 Wheat topdressed in the spring A 1.25 B 1.52 G 1.39 B 1.25 Average 1.35 LSD fortreatment (.05) no ing (.05) not significant. * One cutting only 1.14 0.96 1.18 1.37 1.16 significant. 1.16 0.79 1.14 1.05 1.52 1.20 0.74 0.78 1.13 0.97 LSD for top dress- 51 TABLE 20*- The effect of rates of application of ammonium sulfate on the yield of alfalfa when fall planted in wheat on a Brookston clay loam soil in 1957* Replication Pounds of nitrogen per acre 20 40 0 80 Tons per acre First cutting A B C D Average 2.82 2.72 1.51 1.79 2.21 2.83 2.41 1.99 1.95 2.30 2.04 2.07 1.96 1.83 1.98 2.39 2.09 2.04 2.22 2.19 Second cutting 0.58 0.77 0.81 0.65 0.70 0.55 0.61 0.95 0.92 0.76 0.47 0.80 0.58 0.99 0.71 0.69 0.71 0.67 0.62 0.67 Average 2 cuttings 2.91 3.06 2.69 2.86 1.57 2.08 2.31 1.74 1.93 2.38 1.92 2.43 2.61 2.34 A B G D Average Wheat topdressed in the spring First cutting A B C B Average 2.14 2.28 1.48 1.87 1.94 1.83 2.15 1.58 1.33 1.72 Second cutting 0.41 0.80 0.78 0.72 0.68 0.15 0.51 0.80 0.82 0.57 0.46 0.67 0.52 0.84 0.62 0.51 0.51 0.29 0.48 0.45 Average 2 cuttings 2.62 2.29 2.55 2.79 A B C D Average LSD for treatment (.05) not significant. ing (.01) *59 tons • LSD for topdress. 52 T A B L E 21.- The effect of rates of application of ammonium sulfate on the yield of alfalfa when spring planted in wheat on a Bro ok st on clay loam soil in 1957. Replication Pounds of nitrogen per acre 20 40 0 80 Tons per acre First cutting A B C D Average 2.12 1.16 1.91 2.08 1.82 2.71 1.40 2.90 1.69 2.18 2.58 1.56 1.89 1.92 1.99 2.17 1.54 1.86 2.22 1.95 Second cutting 0.29 0.67 0.56 0.29 0.45 0.53 0.45 0.50 0.37 0.46 0.38 0.55 0.70 0.39 0.51 0.39 0.55 0.50 0.23 0.42 Average 2 cuttings 2.27 2.45 2.69 2.37 1.45 1.35 1.63 2.04 1.62 2.20 0.23 0.36 0.28 0 .33 0.30 2.01 A B 0 D Average Wheat topdressed in the spring A B C D Average 2.24 0.63 1.95 2.20 1.76 2.35 1.42 1.46 2.39 1.91 0.76 1.85 2.04 1.71 Second cutting 0.45 0.58 0.54 0.19 0.44 0.35 0.44 0.63 0.41 0.50 0.65 0.82 0.28 0.56 Average 2 cuttings 2.20 2.32 2.18 A B G D Average 0.20 LSD for treatment (.05) Not significant. ing (.05) .50 tons. LSD for topdress— 53 TAB LE 22.- The effect of rates of application of ammonium sulfate on the percent protein of alfalfa hay following wheat on a Fox sandy loam soil in 1957. Pounds of nitrogen per acre 40 20 Replication 80 Percent protein Wheat and alfalfa fall planted A 16.10* 13.78 14.48 15.56 B 14.30 14.14 14.14 16.27 Average 15.20 13.96 14.31 15.92 Wheat topdressed in the spring A 15.20 15.90 14.66. 15.38 B 15.02 16.10 15.90 15.38 Average 15.11 16.00 15.28 15.38 Alfalfa spring planted in wheat A 12.96 14.84 14.30 15.02 B 13.86 15.02 14.14 15.38 Average 13.41 14.93 14.22 15.20 Wheat topdressed in the spring * A 13.59 13.41 14.48 12.52 B 14.14 14.84 14.14 13.78 Average 13.87 14.13 14.31 13.15 First cutting only. 54 TABLE 23.— The effect of rates of application of ammonium sulfate on the percent protein of alfalfa hay following wheat on a Brookston clay loam soil in 1957. Replication 0 Pounds of nitrogen per acre____ 20 40 80 Percent protein First cutting Wheat and alfalfa fall planted A 13.77 13.95 11.71 B 13.41 12.35 12.43 Average 13.59 13.15 12.07 Wheat topdressed in the spring A 13.41 12.87 13.05 B 14.13 12.07 12.87 Average 13.77 12.47 12.96 Wheat overseeded with alfalfa in the spring A 10.73 12.70 12.25 B 10.37 12.16 11.53 Average 10.55 12.43 11.89 Wheat topdressed in the spring A 10.73 11.18 12.07 B 11.09 8.94 11.35 Average 10.91 10.06 11.71 ^ c o n d out Wheat and alfalfa fall planted 15.56 A 15.56 13.59 15.20 14.39 13.59 B 15.38 14.98 13.59 Average Wheat topdressed in the spring 15.47 15.20 16.18 A 15.02 16.72 16.09 B 16.10 15.11 16.14 Average Wheat overseeded with alfalfa in the spring 14.93 13.41 12.96 A 16.72 15.02 16.09 B 14.22 15.83 14.53 Average Wheat topdressed in the spring 13.41 15.02 12.96 A 15.02 12.69 13.68 B 15.02 13.05 13.41 Average 12.52 12.52 12.52 11.44 10.37 10.91 12.07 12.25 12.16 12.35 13.23 12.79 16.54 16.09 16.32 16.81 17.97 17.39 14.12 17.97 16.05 13.41 11.81 12.61 55 topdressing. The same results are shown in table 21 for alfalfa spring planted in wheat in 1956. Nitrogen treatments gave a slight but insignificant increase in yields about the same as fall planted but the additional nitrogen gave a sig­ nificant decrease. The percent protein in these two blocks of alfalfa are given in table 23 for two cuttings which shows that on a percentage basis the protein content is fairly constant but that the second cutting of hay is much higher than the first cutting. This was found to hold for all plantings of alf­ alfa and is a complete reversal of what was found in the greenhouse studies (table 4). Sources of Nitrogen The sources of nitrogen study was carried out at four locations throughout the state on various soil types with different fertility levels as shown in table 2. The areas selected were at random with no previous knowledge of soil conditions or cropping history and only well established stands of alfalfa were used for this study. The fertilizer treatments consisted of a check (no ni­ trogen) and 30 pounds of actual nitrogen per acre applied as 150 pounds of ammonium sulfate, 90 pounds of ammonium nitrate and 60 pounds of urea, respectively. The first cutting was made on these plots approximate­ ly ten weeks after the fertilizer was applied which was followed by a second cutting six weeks later. Yield increases occurred in three of the four loca­ tions as shown in table 24. These increases occurred in the first cutting, indicating that if nitrogen is benefi­ cial in alfalfa production, it must be applied early in the growing season. There was a highly significant difference in cuttings but none of the nitrogen treatments produced significant yields of hay over the check plot. There were no significant differences found in the protein content due to treatments but a high degree of sig­ nificance was found between cuttings (table 25). 57 TABLE 24.— The effect of sources of nitrogen applied as a topdressing on the yield of alfalfa hay harvested in 1957. Sources of nitrogen Replication Gutting Check Ammonium sulfate Ammonium nitrate Urea Tons per acre Oshtemo loamy sand 1 1 1 1 1 1 1.72 1.38 1.49 1.71 1.25 1.51 1.76 1.34 1.34 1.45 1.84 1. 55 1.91 £.45 1.54 1.45 1.90 1.85 1.68 1.91 0.95 0.81 1.55 0.85 1.08 1.05 1.12 1.24 0.95 1.05 0.96 1.06 0.85 1.04 0.91 1.25 1.11 1.03 0.82 E Average 2 2 2 2. 2 2 Average 1 & 2 2.56 2.61 2.88 2.76 LSD (.05) tons C D E Average A B C D 1.49 1.61 1.80 1.70 1.01 1.16 1.48 0.83 l.Oo Ockley sandy loam A B G D E Average 1 1 1 1 1 1 1.85 2 .03 1.92 1.56 1.79 1.83 2.08 1.36 1.63 2.14 1.31 1.70 1.99 1.35 1.88 2.02 1.21 1.69 2.20 A B Average 2 2 2 2 2 2 0.25 0.72 0.58 0.57 0.47 0.52 0.29 0.75 0.39 0.85 0.49 0.55 0.39 0.58 0.70 0.41 0.87 0.59 0.44 0.49 0.55 0.49 0.42 0.48 Average 1 & 2 2.35 2.25 2.28 2.36 S LSD (.05) 0.47 tons. 1.59 2.07 1.71 1.85 1.88 58 TABLE 24.— The effect of sources of nitrogen applied as a topdressing on the yield of alfalfa hay harvested in 1957. (Continued)* Sources of nitrogen Replication Gutting Check Ammonium sulfate Ammonium nitrate Urea Tons per acre Belfontaine sandy loam A B C D E Average 1 1 1 1 1 1 1.16 1.76 1.38 0.91 1.72 1.39 1.95 1.76 1.58 1.47 1.58 1.67 1.70 1.56 1.67 1.83 1 6.0 1.68 1.63 1.33 1.38 1.80 1.23 1.47 2 2 2 0.57 0.40 0.40 0.40 0.45 0.44 0.57 0.38 0.38 0.53 0.57 0.49 0.42 0.37 0.39 0.38 0. 56 0.42 2.11 2.17 1.89 1.60 1.36 1.30 1.31 1.07 1.33 1.38 1.50 1.52 1. 54 1.58 1.50 E Average 2 2 0.39 0.49 0.30 0.36 0.52 0.41 Average 1 & 2 1.80 A B G D 2 . LSD (*05) 0*42 tons Conover loam A B C D E Average 2 2 2 2 2 2 LSD (.05) 0.19 tons. 1.57 1.40 1.35 1.78 1.45 1.51 1.44 1.50 1.48 1.39 1.23 1.41 0 TABLE 25.- The effect of sources of nitrogen applied as a topdressing on the percent protein of alfalfa hay harvested in 1957. Sources of nitrogen Replication Cutting Check Ammonium sulfate Ammonium nitrate Urea Percent protein Oshtemo loamy sand A B Average 1 1 1 12.61 12.43 12.52 12.78 12.25 12.52 13.68 13.14 13.41 12.70 12.70 12.70 A B Average 2 2 2 19.31 18.77 19.04 19.67 19.49 19.58 17.16 17.52 17.34 17.08 17.08 17.08 Ockley sandy loam A B Average 1 1 1 11.18 12.07 11.63 9.84 9.84 9.84 10.73 8.41 9.57 11.18 10.55 10.87 A B Average 2 2 2 18.33 19.22 18.78 17.78 18.24 18.01 19.23 19.23 19.23 17.97 18.15 18.06 Belfontaine sandy loam A 3 Average 1 1 1 13.23 13.41 13.32 12.96 11.71 12.34 12.87 12.16 12.52 11.80 11.44 11.62 A B Average 2 2 2 15.65 15.82 15.74 18.15 17.97 18.06 17.79 17.70 17.75 17.43 17.08 17.26 Conover loam A B Average jtal average 2 2 2 17.08 17.52 17.30 16.63 16.54 16.59 16.27 16.09 16.18 16.36 16.72 16.54 15.47 15.28 15.14 14.86 LSD for treatment (.05) 0,96 (*01) 1.30 V« SUMMARY AND CONCLUSIONS ■Greenhouse results show that the yield and protein content of alfalfa were increased significantly by the application of nitrogen fertilizer on some soils. the soils, Two of the Oshtemo loamy sand and the Miami loam re­ sponded in yield while these two soils as well as the Brook— ston clay loam, Conover loam and Hillsdale loam produced alfalfa with a higher percent protein. Four significant interactions between nitrogen fertilizer treatments and cuttings were found in the analysis of the protein content while only one interaction was found in the yield data. The total protein produced was significantly higher when the data from all soils were compiled together even though the yield or protein content was not significant when considered separately. This indicated that a slight increase in yield with a slightly higher protein content was needed to give significant results. Residual soil nitrogen analysis showed a significant difference in the nitrogen content due to treatments and that these values were lower than those obtained at the be­ ginning of the experiment. est amount of nitrogen. The check plots showed the low­ Since the experiment was conducted over a short period of time, therefore, not giving the al­ falfa plants very much time for nodulation and nitrogen 60 61 fixation; it is reasonable to expect a direct removal of small amounts of nitrogen from the soil® show that even when the plants are Previous studies well nodulated, some of the nitrogen is taken from the soil® The application of nitrogen fertilizer increased the grain yield and protein content of oats and barley by a significant margin in 1955; however, the yield of hay pro­ duced on these plots the following two years did not give a significant response to the nitrogen fertilizer applied in the spring of 1955 at the were seeded* time the grain crops and alfalfa The percentprotein was increased in 1956, the first year after application but decreased in 1957® Alfalfa planted alone in August did not respond to the nitrogen applications in yield but the protein content was somewhat higher than the check* Wheat yields were increased slgnificantly on all three soil types when nitrogen fertilizer was applied at planting time. Additional nitrogen applied as a topdressing the following spring gave increases at two of the three loca­ tions. The protein content was increased in all of the six blocks of wheat but the only real increase occurred in the two blocks on the Fox sandy loam soil at the Kellogg farm. No significant increases in yield of alfalfa grown on these plots were found the following year resulting from fertilizer treatments* One interaction between fertilizer treatment at planting time and an additional topdressing 62 with twenty pounds of nitrogen was found in the wheat and alfalfa fall planted on the Fox sandy loam soil. The add­ itional topdressing was effective in both blocks of alfalfa following wheat on the Brookston clay loam soil* Hay yields were not taken from the plots following wheat on the Hillsdale loam soil at the University farm due to lodging that occurred the previous year. The stand was very thin on the plots where severe lodging occurred and the yield harvested would not have been a representative sample* The sources of nitrogen study carried out on four dif­ ferent soils indicated that nitrogen fertilizer applied as a topdressing on established stands of alfalfa does not give a significant increase in the yield or the protein con­ tent of the hay. VI. LITERATURE CITED 1. Al i o s , H* F. and W. V. Bartholomew. Effect of avaiJ _ able nitrogen on symbiotic fixation. Soil Sci. Soc. Amer. Proc. 19:182-184. 195b. 2. Attoe, 0. J. and A. E. Peterson. Long-lived alfalfa: keep that good stand as long as you wish. Crops and Soils. 8:10-11. Nov. 1955. 5. Baker, Donald G. , et a l . Influence of fertilizers on four legumes when grown as green manures. Minn. Agri. Expt. Sta. Tech. Bull. 204. 1952. 4. Batham, H. N. 33?. 1925. 5. Blaser, R. E. Alfalfa In mixtures for pastures, and hay. Better Crops. 38:6-10. Dec. 1954. 6. 23-26. Nitrification in soils. . Why more alfalfa? Dec. 1955. Soil Sci. 20. silage Better Crops. 39; ?. Bosemark, N. 0. The influence of nitrogen on root development. Physiol. Plant. 7:497-502. 1954, 8. Briggs R. and C, M. Harrison. The effects of various companion crops on the establishment of alfalfa. Mich. Agri. Expt. Sta. Q,uar. Bull. 36:130-137. 1953. 9. Davis, John F. Field observation regarding the value of root nodule bacteria. Jour. Amer. Soc. Agron. 36 s869-871. 1944. 10. Davis, J. F. and L. M. Turk. The effect of fertilizers and the age of plants on the quality of alfalfa and sweet clover for green manure. Soil Sci. Soc. Amer. Proc. 8:298-303. 1944. 11. Dobson, S. H. and W. W. Woodhouse, Jr. Why grow alf­ alfa. Better Crops. 41:16-23. Aug-Sept. 1957. 12. Fertilizer recommendations for Michigan crops. Ext. Bull. 159. 1954. 13. Fred, E. B., X. L. Baldwin and Elizabeth McCoy. Root Nodule Bacteria and Leguminous Plants. Univ. of Wise. 63 Agri. 64 Press* Studies in Science. sin. 1932. No* 6* Madison. Wiscon­ 14* Fribourg, H. A # and I. J. Johnson* Dry matter and ni­ trogen yields of legume tops and roots in the fall of the seeding yeat. Agron. Jour* 47:73-77. 1955. 15* Gardner, H. W. Nitrogenous dressings to increase pro­ tein in cereals. Agriculture. 60:95-97. 1953. 16. Gerwig, John L. Potash--Key to alfalfa yields. Crops. 42:8-13. April, 1958. I1 ?* Giobel, Gunnar. The relation of the soil nitrogen to nodule development and fixation of nitrogen by certain legumes. N. J. Agri. Expt. Sta. Bull. 436. 1926. 18. Griffith, F. P. Production and utilization of alfalfa. Scon. Bot. pp. 170-183. April, 1949. 19. Gross, H. Douglas, et a l . The response of alfalfa varieties to different soil fertility levels. Agron. Jour. 45:118-120• 1953. 20. Hobbs, J. A. The effect of spring fertilization on plant characteristics of winter wheat. Soil Sci. Soc. Amer. Proc. 17:39-42. 1953, 21. Hunter, H. High protein feeding barley. 59;536-540• 1953. 22. Hutchinson, H. B. and N. H. J. Miller. The direct as­ similation of inorganic and organic forms of nitrogen by higher plants. Jour. Agri. Sci. 4:282-302. 1912. 23. Hutchinson, J. B. and H. F, Martin. The chemical com­ position of oats. II. The nitrogen content of oats and groats. Jour. Agri. Sci. 45:419-427. 1955. 24. Larson, W. E . , L. B. Nelson and A. S. Hunter. The effects of phosphate fertilization upon the yield and composition of oats and alfalfa grown on phosphate de­ ficient Iowa soils. Agron. Jour. 44:257-361. 1952. 25. Lyon, T. L. and J. A. Bizzell* A comparison of several legumes with respect to nitrogen accretion. Jour. Amer. Soc. Agron. 26:651-656. 1934. 26. McAuliffe, Clayton, et a l . Tagged nitrogen. Research and Farming. pp* 9—IS. Vol. 13. 1954— 1955. 27. McLean, E. 0., et a l . Cation exchange capacities as related to their nitrogen consent* Soil Sci* Proc. 20£345-347. 1956. Better Agriculture 65 8» McNeal, F. ^N. arid D. J® Davis* Effect of nitrogen fertilization on yield, culm number and protein con­ tent of certain spring wheat varieties* Agron. Jour* 46£375-576* 1S54* 29. Melklejohn, Jane* The nitrifying bacterial Jour, of Soil Sci. 4:59-68. 1953* A Review* 30* Mulder, E. Gr. Magnesium nutrition of agricultural crops particularly in connection with nitrogen ferti­ lizing* Landbovwk Bur. Ned* Stikstofmeststoffen Industr* Publ. pp. 16. 1951* 31* Official Methods of Analysis* Published by the A s s Bn of Official Agricultural Chemist. Washington. D. G, 1950* 32. Peterson, A. E. Hoards Dairyman, 33. Peterson, Howard B. Effect of nitrogen fertilizer on yield and protein content of winter wheat in Utah. Utah Agri* Expt. Sta. Bull. 353. 1952. 34. Piper, C. S. Soil and Plant Analysis. Interscience Publishers Inc. New York, N. Y. 1950. 35. Prince, Allan B* Yield and chemical composition of annual ryegrass and crimson clover as affected by ni­ trogen and potassium fertilization* Soil Sci. 78:415427. 1954. 36* Purvis, E. R* Nitrogen boost yields and protein con­ tent of alfalfa* New Jersey Agriculture. 37:12-13. Nov. Dec. 1955* 37. Rouse, Hayden K., et al* High altitude meadows in Colorado. I. Effect of irrigation on hay yield and quality. Agron. Jour. 47:36-40. 1955* 38. Rendig, V. V. Sulfur and nitrogen composition of fer­ tilized and unfertilized alfalfa grown on a sulfur de­ ficient soil. Soil Sci. Soc. Amer. Proc. 20:237-240. 1956. 39. Shields, Lora Mangum. Nitrogen sources of seed plants and e n v i r o n m e n t a l influences affecting the nitrogen supply. Bot. Rev. 19:321-376. 1953. 40. Smith, Dale, et al. Establishment of legumes as in­ fluenced by the rate of sowing the oat companion crop Agron. Jour. 46:449— 451. 1954* How much fertilizer for alfalfa? pp. 600-601. June 25, 1955. 66 41. Spurway, G. H. and K. Lawton. Soil Testing, a practi­ cal system of soil fertility diagnosis. Mich. Agri. Axpt. Sta. Tech. Bull. 132. 1949. 42. Starter boost needed. 43. Duman, R. F. Initial fertilizer applications key to clover establishment on forested coastal plain soils. Agron. Jour. 46:241. 1954. 44. Stojanovic, B. J. and F. E. Broadbent. Immobilization and mineralization rates of nitrogen during decomposi­ tion of plant residues in the soil. Soil Sci. Soc. Amer* Proc. 20:213* 1956. 45. Swanson, C. 0. The effect of prolonged growing of alfalfa on the nitrogen content of the soil. Jour. Amer. Soc. Agron. 9:305-314. 1917. 46. Tisdale, S. L., et al. Sources of nitrogen in crop production. N. C. Agri. Expt. Sta. Tech. Bull. 96* 1952. 47. Thornton, George Daniel. The effect of nitrogen fer­ tilization on the nitrogen nutrition of legumes. Iowa State Coll. Jour, of Sci. 22:84-66. 1947-1948. 48. Treggi, G. Comparative effect of sodium nitrate and calcium nitrate on Luoinus Albus L . Ann. Sper. Agrar. Roma. 6:1435-1440. 1952. 49. Woodhouse, W. W . , Jr. and D. S. Ghamblee. Nitrogen in forage production. N. C. Agri. Expt. Sta. Bull. 383. 1953. 50. Wagner, R. E. Influence of legume and fertilizer ni­ trogen on forage production and botanical composition. Agron. Jour. 46:167-171. 1954. 51# . Legume nitrogen vs. fertilizer nitrogen in protein production of forage. Agron. Jour. 46:233237. 1954. 52. Waksman, Selman A. Microbial analysis of soil as an index of soil fertility. Ill* Influence of fertili­ zation upon numbers of microorganisms in the soil. Soil Sci. 14:321-346. 1922. 53* Walker, T. W . , et a l . Fate of labeled nitrate and ammonium when applied^to grass and clover grown separ­ ately and together. Soil Sci. 81:339—351. 1856. Better Crops. 42:20. April, 57 54. Wedin, W. F . , A. W. Burger and H, L. Ahlgren. Effect of soil type, fertilization and stage of growth on yield, chemical composition, and biological value of Ladino clover trlfoliuim repens L . and alfalfa medicago sativa. Agron. Jour. 48-147-152. 1956. 55. Williams, B. C. and F. W. Smith. The effect of dif­ ferent rates, times and methods of applications of various fertilizer combinations on the yield and quality of hard red winter wheat 1949-1950. Soil Sci. Amer. Proc. 18*56-60. 1954. 56. Yatazawa, M . , et al. Effect of nitrogen topdressing on phosphorus intake and accumulation in wheat. J. Sci. Soil Man. Japan. 23;121-124. 1953. VII. APPENDIX TABLE 1.- The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on Oshtemo loamy sand. Replication 0 Pounds of nitrogen per acre 20 40 80 160 Percent protein First harvest, April 5 A B C D Average 7.75 5.32 5.59 6.58 6.31 7.52 5.21 6 .52 6.59 6.46 7.60 8.42 7.63 8.92 7.64 8.49 8.12 9.84 8.12 8.64 11.85 8.47 6.03 9.07 8.85 8.68 8.10 6.83 7.09 7.66 7.14 6.44 6.31 6 .61 6.67 8.09 6.64 8.04 7.37 7.53 Second harvest, May 1 7.26 5.83 4.62 6.12 5.94 A B G D Average 6.60 6.06 5.42 6.35 6.11 Third harvest, June 3 9.89 7.25 8.80 8.42 8.58 10.28 8.71 8.10 10.03 9.28 8.24 8*35 11.13 10.25 9.49 8. 56 11.17 9.83 8.40 9.49 10.01 9.09 8.98 10.24 9.58 Average of 3 cuttings 6.95 7.28 8.26 8.27 8.66 LSD (.05) 1 .47 1*97 A B C D Average (.01) 68 39 TABLE 2.- The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the green­ house in 1955 on an Oshtemo loamy sand. Replication 0 Pounds of nitrogen per acre_____ 20 40 80 160 Percent protein First harvest, April 5 A 16.35* 16.53 18.20 14.67 16* 61 B 15.47 14.14 15.55 15.91 16.17 C 16.44 13.87 14.23 15.55 18 .56 D 15.29 16.88 14.05 15.73 17.50 Average 15.89 15.36 15.51 15.46 17.21 Second harvest, May 1 A 18.20 19.35 13.60 16.44 18.47 B 15.11 15.64 17.67 19.62 17.14 C 16.26 16.17 18.03 18.65 16.03 D 14.14 17.85 19.62 14.25 17.94 Average 15.92 17.25 17.23 17.23 17.89 Third harvest, June 3 A 13.08 16.17 16.26 17.32 16.26 B 14.14 13.87 16.08 16.26 16.67 G 16.97 16.35 14.23 15.55 14.85 D 15.20 14.32 14.58 12.90 15.11 Average 14.85 15.18 15.29 15.51 15.77 iD (.05) 2.05 Kj eldahl x 6.25 (.01) 2.74 70 TABLE 3.— The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1956 on Hillsdale loam. Replication 0 Pounds of nitrogen per acre 20 80 40 160 G-rams per pot First harvest, April 23 A 5.30 5.79 3.63 4.90 5.50 B 4.70 4.64 6*^5 5.50 6.35 G 5.07 4.82 5.90 5.55 6.32 D 3.84 4.94 4.55 5.21 4.94 Average 4.75 5.04 5.13 5.24 5.78 Second harvest, May• 4 A 13.00 11.70 11.00 11.50 10.90 B 11.80 13.50 13.00 11.70 13.10 C 12.90 11.80 14.50 11.80 11.40 D 10.20 11.70 10.70 13.30 14.20 Average 11.97 12.17 12.30 12.07 12.40 Third harvest, June 1 A 13.17 13.66 13.38 12.61 11.27 B 10.82 14.80 13.13 16.52 13.65 G 11.34 13. 60 15.28 17.38 12.40 D 12.59 11.00 10.82 17.47 15.02 Average 11.98 13.26 13.15 15.99 13.09 9.56 10.16 10.19 11.12 10.42 Average of 3 cuttings LSD (.05) 1 .86 (.01) 2.48 71 TABLE 4.— The effect of rates of application of a m m o n i u m sulfate on the percent protein of alfalfa grown in the greenhouse in 1956 on a Hillsdale loam. glieation 0 Pounds of nitrogen per acre 160 20 40 80 Percent protein First harvest, April 5 A 1 7 .35# 16 .96 19.76 21.12 23.12 B 17.15 16.94 20.00 21.50 23.50 Average 17.25 16.94 19.88 21.33 23.31 Second harvest, May 1 A 20.05 19 *60 22.00 20 .80 19.80 B 19.75 19.20 18.60 19. 10 17.80 Ave rage 19.90 19.40 20.30 19.70 18.80 Third harvest, June 3 A 14.92 17.20 16.70 17.15 17.00 B 16.65 16.58 16.70 17.85 18.00 Ave rage 15.91 16.79 16.70 17.50 17.50 SD (.05) 1. 55 (.01) 2.16 Kj eldahl x 6.25 72 TABLii*^5*- The effect of rates of application of ammonium sulfa be on the yield of alfalfa grown in the greenhouse in 1956 on Conover loam* Replication 0 Pounds of nitroeren per acre 40 20 160 80 Crams per pot First harve st, April 23 A 6 .93 6.61 6.05 6.00 7.22 B 6.25 5.57 7.20 6.35 7.67 C 5.92 5.80 7.88 6.25 5.86 D 5.12 6.20 6.45 5.78 4.52 Average 6.05 6.05 6.89 6.22 6.32 Second harvest, May 4 A 6.40 7.80 7.40 7.50 9.00 B 6.40 6.20 7.60 7.50 7.40 C 8.80 7.20 7.40 6.80 8.40 D 7.60 6.40 7.70 9.10 6 .50 Average 7.30 6.90 7.50 7.70 7.60 Third harvest, June 1 A 10.75 13.49 11.10 9.92 13 .06 B 9.33 12.13 11.51 10.67 12.30 G 12.17 10.07 12.44 11.27 11.95 D 12.54 11.83 11.34 12.75 11.95 Average 11.20 11.88 11.60 11.15 11.99 8.16 8.28 6.67 8.37 6.71 Average of 3 c uttings LSD (.05) 2.67 (•01) 3.56 TABL& 6*- The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1956 on a Conover loam* Replication 0 Pounds of nitrogen per acre 20 40 80 160 Percent protein First harvest, April 23 A 19*00* 20.00 20.22 21.76 19.82 B 18.50 20.24 20 .66 21.36 20.18 Average 18.75 20.12 20.44 21.56 20.00 Second harvest, May 4 A 17.75 18.80 19.80 18.30 18.90 B 17.65 18.60 19.00 17.30 18.90 Average 17.70 18.70 19.40 17.80 18.90 Third harvest, June 1 A 15.02 14.69 16.47 15.04 17.68 B 15.02 14.47 15.70 15.00 16.08 Average 15.02 14.58 16.17 15.02 16.88 ( *05) 1.76 Kjeldahl x 6.25 (.01) 2.45 TABLE ?.— The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on Miami loam. Replicat ion 0 Pounds of nitrogen per acre 20 160 40 80 Grams per pot First harvest, April 5 A 6.84 6.85 7.44 9.72 8.10 B 4.91 7.57 8.97 9.26 6.14 G 6.30 5.32 8.02 9.46 9.13 D 5.34 6.84 7.84 6 .45 7.98 Average 5.85 6 .64 8.07 8.72 7.84 Second harvest, May 1 A 10.55 9.07 10.78 12.95 9.67 B 9.11 10.23 10.35 9.94 7.19 G 8.84 7.36 10.65 11.96 8.77 D 8.82 9.99 12.21 9.11 11.16 Average 9 .33 9.16 11.00 10.99 9 .20 Third harvest, June 3 A 10.05 7.64 8.53 12.79 9.79 B 10.48 9.73 13.33 9.68 7.62 G 8.07 6.68 10.55 11.26 10.78 D 8.35 10.43 10.73 10.07 11.68 Average 9.24 8.62 10.79 10.95 9.97 8.14 8.14 9.95 10.22 9.00 Average of 3 cuttings LSD (.05) 2.00 (.01) 2.67 75 TiiBLE 8.- The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1955 on Miami loam. plication 0 Pounds of nitrogen per acre 2q 160 40 80 Percent protein First harvest, April 5 A 17.85* 19.35 19.62 18.74 21.38 B 18.47 18.29 19.35 18.82 20.50 G 18.12 18.47 14.94 18.56 21.30 D 21.03 21.03 18.29 21.38 21.38 Average 18.87 19.28 18.05 19.38 21.14 Second harvest, May 1 A 16.08 19.00 15.02 16.97 20.68 B 17.14 18.47 15.82 16.98 20.06 G 17.85 19.09 15.20 17.05 18.20 D 18.91 19.88 15.55 20.66 18.65 Average 17.49 19.11 15.40 17.96 19 .40 Third harvest, June 3 A 18.29 18.47 18.03 15.11 18.65 B 16.00 17.49 17.23 18.12 19.27 C 18.12 17.67 16.88 18.29 16.35 D 18.56 16.00 17.06 16.35 15.03 Average 17.74 17.41 17.30 16.98 17.32 ID (.05) 1.77 ( .01) 2.36 Kjeldahl x 6.85 76 TABLE 9,- The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1956 on Fox sandy loam. Replication 0 Pounds of nitrogen per acre 20 160 40 80 Grams per pot First harvest, April 23 A 5,01 5.60 3.88 5.75 5.61 B 6,75 5.18 7.37 4.07 5.27 G 5.04 4.07 5.00 5.15 5.28 D 5,05 4.68 5.79 3.87 3.78 Average 5.46 4.89 5. 51 4 .66 4.97 Second harvest, May 4 A 14.50 14.00 10.30 13.00 14.00 B 13.40 11.40 10.80 10.90 13.20 G 11,70 12.00 12.30 14.10 10.80 D 10.40 12.20 13.00 10.80 12.20 Average 12.50 12.40 11.60 12.20 12.50 Third harvest, June 1 A 17.58 17.58 13.79 14.56 20.12 B 20.37 13.65 18.35 17.51 16.70 C 14.59 15.07 16.96 16 .60 15.42 D 13.50 16.07 15.52 13.85 15.20 Average 16.51 16.15 15.60 16 .86 11.09 10 .65 11.46 Average of 3 cuttings 11.49 LSD (.05) 1,92 (.01) 2,56 15.49 10.96 77 TABLE 10.- The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1956 on a Fox sandy loam* ^plication 0 Pounds of nitrogen per acre 150 60 20 40 Percent protein First harvest, April 23 A 19 *30* 19.90 22.15 22.22 23.40 B 16.82 19.86 22.35 22.65 23.48 Average 19*06 19.88 22.25 22.44 23.44 Second harv est, May 4 A 19.55 15.36 21.00 26.35 16.90 B 19.45 20.24 18.60 17.45 16.90 Ave rage 19.50 17.80 19.80 17.90 16 .90 Third harvest, June 1 A 15.36 17.60 16.23 15.95 16.01 B 16.80 16.86 16 .11 15.87 16.33 Average 16.08 17.23 16.17 15.91 16.17 3D (.05) 2.35 ( .01) 3.25 Kjeldahl x 6.25 78 The effect of rates of application of ammonium sulfate on the yield of alfalfa grown in the greenhouse in 1955 on a Broohston clay loam. Replication 0 Pounds of nitrogen per acre 160 20 80 40 Grams per pot First harvest, April 5 A 10.10 9.69 7.30 12.89 12.22 B 8.95 10.93 10.90 10.48 12.51 C 10.90 12.64 14.52 9.47 9.07 D 6.93 9.48 9.37 9.34 13.88 Average 9.72 10.68 10.52 10.54 11.92 Second harvest, May 1 A 11.73 10.72 6.87 14.50 16 .60 B 10.74 14.38 12.86 12.59 12.52 G 14.11 10.83 13.34 10.75 10.09 D 11.21 11.30 9.99 10.18 15.19 Average 11.95 11.81 10.76 12.00 13.65 Third harvest, June 3 A 12.87 11.97 6 .30 12.63 15*39 B 9.64 13.32 12.95 12.13 12.80 G 13.22 12. 56 15.47 9.47 7.61 D 9.58 11.20 8.80 12.02 16.60 11.33 12.26 10.88 11.61 13.13 Average of 3 cuttings 10*99 11.58 10.74 11.45 12.69 LSD (.05) 3.49 (.01) 4.67 Average 7b TABLE 12.- The effect of rates of application of ammonium sulfate on the percent protein in alfalfa grown in the greenhouse in 1955 on Brookston clay loam. Replication 0 Pounds of nitrogen per acre____ 20 40 80 160 Percent protein First harvest, April 5 A 17.76* 21.74 1'c/.o3 H o o. 18.56 B 22.36 21.47 19 .35 20.24 20.94 C 19.35 20.79 19.27 19.36 21.21 D 19.97 19.62 18.12 20.86 18.12 Average 19.86 20.90 19.09 19.86 19.71 Second harvest, May 1 A 19.44 21.21 16 .44 20.68 14.85 B 18.74 18.03 16.79 15.55 16.35 C 18.64 19.18 17.67 17.14 18 .65 D 16.91 16.53 17.50 17.23 14.23 Average 18.93 18.74 17.10 17.65 16.02 Third harvest, June 3 A 17.49 18.03 17.94 18.47 15.46 B 18.47 16.97 17.32 18.29 15.91 G 18.38 18.56 17.76 17.67 17.85 D 18.47 16.56 17.67 19.53 16.79 Average 18.20 18.03 17.67 18.49 16 .50 L5D (.05) 1.82 (.01) 2.43 * Kjeldahl x 6.25 TABLE 13*- The effect of rates of application of ammonium sulfate on the yield of alfalfa following oats on a Fox sandy loam soil. Replication 0 Pounds of nitrogen per acre 20 40 80 Tons per acre First. cutting, 19 56 A 1.30 1.60 1.20 1.60 B 1.40 1.65 1.50 1.30 G 1.45 1.60 1.30 1.50 D 1.25 1.10 1.00 1.00 Average 1.35 1.49 1.25 1.35 Second cutting, 1956 A 0.64 0.85 0.80 0.70 B 0.76 0.70 0.45 0.85 C 0.40 0.55 0.42 0.35 D 0.70 0.70 0.60 0.85 Average 0.63 0.70 0.57 0.69 Total 1.98 2.19 1.82 2.04 LSD (.05) 0.22 tons. First Gutting, 1957 A 1.90* 1.83 1.32 1.52 B 1.95 2.08 2.02 2,12 0 2.04 1.76 1.73 2.06 D 1.92 2.30 2.05 2.40 Average 1.95 1.99 1.78 2.03 LSD (.05) 0.29 tons - not significant * Only one cutting in 1957 TABLE 14.- The effect of rates of application of ammonium sulfate on the yield of alfalfa following oate on a Hills­ dale loam soil. Replication 0 Pounds of nitrogen per acre 20 40 80 Tons per acre First cutting, 1S56 A B C D Average 2.03 1.73 1.91 2.10 1.94 2.29 1.94 1.50 2.16 1.97 2.02 1.97 1.85 2.12 1*99 1.31 1.52 1.26 1.49 1.40 1.17 1.26 0.95 1.44 1.21 1.12 1.47 0.90 1.44 1.23 3.35 3.18 3.22 3.05 1.93 2.99 2.66 2.66 2.52 2.41 2.81 2.49 2 ,56 1.74 2.15 2.02 1.90 1.95 Second cutting, 1956 C D Average 1.24 1.64 0.96 1.52 1.34 3.28 Total LSD — not significant First cutting, 1957 A B C D Average 2.62 3.92 3.42 2.71 3.17 2.02 2.30 2.34 2.54 2.30 Second cutting, 1957 A B G D Average 1.79 2.12 1.60 1.58 1.77 1.71 1.92 1.35 1.85 1.71 1.77 1.92 1.19 1.41 1.57 1.79 1.50 1.26 1.82 1.59 Total 4.94 4.01 4.23 4.15 LSD -- not significant. TABLE 15.- The effect of rates of application of ammonium sulfate on the yield of alfalfa when seeded alone in August on a Hillsdale loam soil. Replication 0 Pounds of nitrogen per acre 20 40 80 Tons per acre First cutting, 1056 A B G D 1.36 1.13 1.20 1.22 0.74 1.12 1.20 1.06 1.18 0.00 1.14 1.44 1.31 1.28 0.72 1.11 Average 1.25 1.05 1.19 1.11 Second cutting, 1956 0.89 0.80 0.61 0.52 0.74 0.59 0.52 1.01 0.85 0.59 0.96 0.46 1.01 0.63 0.59 0 .61 Average 0.71 Total 1.96 LSD --not significant. 0.72 1.77 0.72 1.91 0.71 1.82 A B C D First cutting, 1957 A B 0 D 2.15 2.50 2.37 1.87 2.25 2.34 2.22 2.15 2.27 2.34 2.38 2.34 2.20 2.22 2.37 2.14 Average 2.22 2.24 2.33 2.23 1.47 1.72 1.27 1.82 1.4S 1.55 1.36 1.71 1.87 3.00 1.53 3.76 Second cutting, 1957 A B Q D Average Total' 1.43 1.41 1.41 1.75 1.50 3.72 1.54 1.80 1.35 1.82 1.63 3.87 63 TABLE 16.~ The effect of rates of application of ammonium sulfate on the yield of alfalfa following "barley on a Brookston clay loam soil* ______ Pounds of nitrogen per acre______ Replication 0 2q 40 80 Tons per acre First cutting, 1956 A B C D 2.22 1.67 1.95 1.55 1.90 1.45 1.97 1.46 1.76 0.87 1.85 1.40 1.63 0.78 1.76 1.08 Average 1.85 1.70 1.47 1.31 1.38 1.13 1.86 1.79 1.35 1.68 1.41 2.09 1.43 1.42 1.51 1.44 1.54 3.24 1.63 3.10 1.48 2.79 Second cutting, 1956 A B G D 1.38 1.59 1.46 1.69 Average 1.53 Total 3.38 LSD (.05) not significant First cutting, 1957 A G D 2.45 2.45 2.25 2.12 2.31 2.35 2.45 2.66 2.42 2.42 3.08 2.45 2.08 2.15 2.75 2.30 Average 2.32 2.44 2.59 2.^2 0.92 0.89 1.36 1.69 1.12 1.06 0.85 1.05 1.20 0.82 0.98 0.92 1*22 3.66 1.02 3.61 o.oO B Second cutting, 1957 A B D 0.70 1.16 1,20 0.77 Average 0,96 Total 3.28 LSD (.05) not significant. 64 TABLE 17.- The effect of rates of application of ammonium sulfate on the yield of alfalfa when seeded alone in August on a Brookston clay loam soil. Replication 0 Pounds of nitrogen per acre 20 40 80 Tons per acre First cutting, 1956 A B G D 1.21 1.32 1.10 1.23 1.71 1.63 1.25 1.49 2.00 1.71 1.48 1.62 1.65 1.53 1.23 1.71 Average 1.22 1.52 1.70 1.53 Second cutting, 1956 A B G D 1.12 1.96 1.16 1.20 0.90 1.38 1.12 0.83 1.41 1.55 1.58 1.39 1.15 1.23 1.49 1.61 Average Total 1.36 2.58 1.06 2.58 1.48 3.18 1*37 2.90 LSD (.05) 0.63 not significant First cutting, 1957 A B G D 1.96 2.19 2.37 2.12 1.71 1.84 1.98 2.19 2.31 2.22 2.16 2.18 1.98 2.14 1.99 2.15 Average 2.16 1.93 2.22 2.07 Second cutting, 1957 A B C D 0.76 0.87 1.33 0.69 0.73 1.07 1.31 1.19 0.91 0.86 1.25 1.12 1.17 1.09 1.09 0.77 Average 0.91 1.08 1.04 1.03 Total 3.07 3 .00 3.26 3.10 LSD (.05} not significant