OUTLINES OF SOIL SUBJECTS FOR Ate 2k Thesis for the Degree of M. Agr. Oa aa Set a7 yf 1914 952 CUTLILES Ca SOIL SUBJECTS CR TEACHERS Thesis for Depree of LASTHA Cr AGHICULTURE a Charles Henry snurweay ee THESIS PREFACE Teaching outlines give logical sequence to subject matter. These outlines are not by any means complete, but they include the most practical and the best founded data of the present time. They are not intended to fur- nish subject matter for lectures, but rather to nold the line of thought directly upon one subject. They should be supplemented by other information gatnered from the literature end teacher's own experience. C. H. 5S. 103869 SOIL FORMATION. A. Soils are formed froin rocks. _ 1. The amount of plant food in rocks varies witn the different kinds, and the fertility of a soil depends somewnat upon the kind of rocks decomposed. 2. Discuss tne effects of the following on rock decay and soil formation, (a ( Air, wind, oxygen, and carbonic acid gas. oO Heat and cold. Q 2 Ice - glaciers. Plants and animals. o ) ) ) Water - freezing and thawins, solution, etc. ( ( ( (f) Lowal examples inay be: (1) Sand dunes, sand or gravel pits (wind and water), brown streaks of iron rust in soils and clay banks, lime in well water, etc. (2) Expansive power of freezing water. (3) Soil materials deposited in different places by running water. (4) Soil formations left by ice sheet. (5) Muck and swamp soils, work of earth worms, burrowing animals, beaver dams, etc. 5. Merrill's Classification of soils. (a) Sedentary soils. (1) Residual - decay of rocks in place. (2) Cumulose - accumulated materials. (bo) Transported soils. (1) Gravity or colluvial - on slopes. 4. ct) (2) Water (a) Marine - on sea coasts. b) Lacustrine - lake bottoms. c) Alluvial - river deposits. (3) Glacial soils - formed by slaciers. (4) Aeolion soild@ - formed by wind. How to tell the different soil formations: (a) Residual - absence of evidences of ice and water action, usually highly colored - red or yellow, presence of refractory materials, texture not uniforn. (bo) Cumulose - Accumulations of partially decayed plant remains. (c) Gravity or colluvial soils - Accumulations on side hills and at bottoms of steep slopes. (d) Water: (1) larine - stratified materials deposited in siallow water salon: sgnores. (2) Lacustrine - unassorted glacial material on bottoms of old slacial lakes. (3) Alluvial - Stratified materials in river valleys. (e) Aeolian - assorted, rounded, material usually in layers or piles. (f) Glacial - unassorted materials found in formations peculiar to glaciated regions. In the process of soil formation different soils have been formed. (a) Discuss soil provences of the United States and their formation. - Use map. (ob) Discuss the general soil formations of ki chigan. - Use map. (c) Discuss the formation and relative fertility of the followins ktichigan soils and show causes. (9) Upland soils. Lowland soils. River bottoms. Swamp and mucks. Prairie soils. Asn and elm bottom lands. Beech and maple soils. Oak openings soil. Oak and hickory soils. (10) Black walnut land. ( ( ( 11) 12) 13) Northern hardwood lands. Wniite pine soils. Jack pine soils. ©) PHYSICAL PROPERTIES OF SOILS. A. A _s0il is made up of small particles called soil grains. 1. The soil grains are of many sizes, shapes and colors. 2. Pore space. (a) (b) (c) The space between soil particles is called pore space. (1) Pore space is due to the shape of the particles. (2) The amount of pore space depends upon size, shape, degree of packing of soil grains, and kind and quantity of soil matdrials. Show presence of pore space by pouring water on sand in graduate. Determine per cent of pore space ina sandy soil. (a) Discuss pore space in sand, loam, clay, and muok (e) (f) soils; also in soils and subsoils. Make list of things in the pore space of soils - air, water, plant roots, bacteria, etc. Make list of processes that go on in soil pore space solution, absorption, nitrification, etc. 3. Texture, structure, and tilth. (a) (0) (¢) (a) Texture refers to the size of soil grains. Btructure refers to arrangement of soil grains. Tilth refers to degree of structure under field con- ditions - good tilth proper structure for any soil; poor tilth improper structure. Note. = Show examples of above. Show classes of soil as determined by texture - mechanical analysis. 4. Crumb structure. (a) (b) Show difference between crumb structure and single grain structure. Show crumb structure with per cent of pore space - by diagram. oO (c) Show how small grains may fall between large ones and reduce pore space. (ad) Show what "puddling" the soil means. 5. Causes of crumb structure. (a) Water content. (») (c) (a) (e) (1) Soils must contain the right amount of wat _er when they are worked by tillage implements. (2) Surface tension. (a) Explain surface tension - float needle on water. (b>) Show action ot films, and location on frames by soap bubbles. - The film always accupies the smallest possible area. (c) Show water films on soil grains - one grain, two grains, three or more grains. (a) Show action of films on body of soil - pyarmid on watch glass. Organic matter. (1) Binding power on sand and separating power on Clay. . Colloidal material. (1) Composed of clay, silica, iron, and aluminum hydroxide, other hydrated compounds, and organ- ic matter, and exerts a binding power. Soluble salts. (1) Have binding power and flocculate or deflocculate colloidal material. Cohesion. (f) Frost - ice crystals. (g) Changing volume. (1) By frost. (2) By expansion and contraction. (h) Biological factors. (1) Drainage. 6. Benefits of crumb structure. (a) (d) (c) (d) (e) 7. How (a) () (c) Free passage for roots. Better movement of water and plant food. More complete aeration. Freer drainage. Better germination of seeds. crumb structure may be destroyed. By heavy rains. By working soil when too wet. By deflocculating chemical compounds - alkalies and phosphates. 8. Means of modifying crumb structure. (a) (b) (c) (a) (e) (f) (g) (h) By controlling water content. (1) By tillage to form soil mulch. (2) By tillage to compact the soil. (3) Other kinds of mulches. Development of ice crystals. Tillage. Growth of plant roots. Organic matter. Fertilizers. Growth of animals, etc., withinthe soil. Controlling effects of heavy rains. ORGANIC MATTER IN SOILS. A. Organic matter in soils is the name given to decayed or decaying plant and animal life of the soil. l. Physical properties of organic matter; (a) Has great absorbtive power for: 1) Water. 2) Substances in solution. 3) Gases. (>) Gives dark color to soils - discuss heat relation- ship. (c) Swells greatly when wetted. (ad) Organic matter may be waxy and repel water to a certain degree. ze Chemical properties of organic matter. (a) Chemical composition. (o) Chiefly protein, fat and carbohydrates. liay con- tain resins, hydro-carbons, alkaloids, acids, etc. (c) Contains the plant food - nitrogen. 5. Effects on soil. (a) Increases coherence, density, capacity for water, end absorbtive power. (bo) Promotes tilth, aeration, water supply, and furnishes nitrogen, phosphoric acid and potash to a certain extent. (c) Effects nitrification. (ad) Prevents leaching and erosion. 4. Decomposition of organic matter in soils. (a) Effected by bacteria (See soil bacteria.) (o) The richer the soil in humus the more rapidly is plant food made available. (c) In arid regions and on sandy soils in humid regions organic matter decomposes rapidly - oxydized. (ad) A free circulation of air and sufficient supply of lime are necessary to the decomposition ofr organic (e) (f) (g) (h) (1) matter. Only humified organic matter can be directly nitrified. In decay oxygen and hydrogen are last, which means that nitrogen containing both resist the action of decay longer than carbohydrates; or that the carbo- hydrates leave the soil first along with the easily decomposed nitrogen compounds - amino acids. Under natural conditions vegetation fails wnen humi- ficatien ceases or becomes raw hunus. More humus is found in pasture or forest than ina tilled field because of better aeration in a culti- vated field, hence faster decomposition. The effect of green manure is increased by the addi- tion of barnyard manure due to the inoculation of bacteria of decomposition. (j) Decomposing organic matter in soils forms compounds with phosphorus which may become available again. 5. Organic matter and soil fertility. (a) Decomposing organic matter in tne soil necessaryto (1) (c) (a) fertile soils - supplies nitrogen and causes bpene- ficial structure. Lack of fertility very often due to lack of organic Matter. Soils which have grown corn, potatoes, end small grains, without manure are usually deficient in organic matter. Crop rotation benefits soils by supplying organic matter when certain crops are used. Crop rotation increased the fertility of North Dakota soils about 50% due to the addition of organic matter alone. 6. Maintenance of organic matter in soils. (a) (b) (c) Applying manures. Green manuring. Crop rotation, including legumes, etc. SOIL WATER. A. Functions of water in the plant. 1. Re Se 4. 5. 6. 7. Carries mineral food into the plant. Transfers food from part to part in the plant. Plants take most of their hydrogen from the water. Forms part of plant tissues. Helps to keep the plant rigid. Regulates physical functions - temperature, transpir- ation, etc. Amount of water used by crops. B. Kinds of water in the soil. 1. Ze de Hygroscopic water. Capillary water. Gravitational water. Note. = show the different forms by pouring water through soil in the funnel. C. Hygroscopic water. 1. Ze Of eamell practical importance. Plants can take very little from the soil - show table. D. Capillary water used by plants. l. Power of soils to hold capillary water - experiment. (a) Depends upon texture, structure, organic matter, material. (ob) Show charts - tne effect of organic matter on dis- tribution of capillary water. (c) Best esemount for plant growth is about one-half capacity of pore space. 2. Power of soils to move capillary water. E. (a) () (c) (4) Describe capillarity. Depends upon texture, structure, organic matter, materi al. Extent to which movement takes place - clay subsoils best, very little horizontal. Relation of surface tension to capillarity. . Gravitational water. l. Harmful. Must be removed by drainage. 2. Drainage depends upon texture, structure, organic mater. 3. May be injurious: (a) (b) (c) (d) (e) By keeping out the air. Making the eoil cold. preventing formation of nitrates. Promoting formation of poisonous compounds. Retarding decay. F. Loss ot soil water. Ge l. By percolation. 2e By evaporation. 5. BY growing plants. Control of soil moisture. 1. Tillage - mulching. Discuss fully. (a) (b) (c) (a) (e) (f) (g) (h) (1) (j) (k) (1) Describe mulch - give different kinds and useé. Mulching effect of plow, harrow, roller. What the mulch does. Depth =- clay and sand. Mulching after a rain. The effectiveness depends upon fineness and dryness. Effect of fall and spring plowing on saving water. Effect of early plowimg on saving water. Effect of cultivation on drawing water to the surfece. Time required for a heavy rain to soak into a soil. Effect of ordinary and frequent cultivation on saving of water yield of corn. The drying of a sandy soil by clover. A. F. 11 SOIL AIR. Air is necessary to plant growth - COpg, oxygen. 1. All parts of the plant take in oxygen and give off COs - respiration. 2. The green parts of a plant take in COs and give off oxygen - photosynthesis. Soils need to be aerated. 1. Plant roots, bacteria, animals, insects, oxidation, nitrogen for nitrification, allow COo to escape, germination of seeds. Composition of soil air. l. Ae affected by decaying orgunic matter, etc. How air gets in and out of the soil. 1. Changes in temperature. ze. Changes in pressure. 5. ovement of water. 4. Diffusion of gases. 5. Upward movements of air. Factors determining the amount of air in the soil. lL. Texture. (a) Soils may be aerated too much - kind. (ob) Soils may be aerated too little - kind. 2. Structure. 4. Organic mattef. 4. Moisture changes. How volume and movements of soil air may be regulated. 1. By tillage. 2. Mulching. 3. Drainage. 4. Irrigation. 9. Cropping. SOIL MULCHES. A. A soil mulch is usually considered to be a soil covering. This soil covering: may be composed of many different meterials. 1. Discuss meterials. B. Objects of the soil mulch. 1. Conserves moisture. 2. Regulates temperature. 5. Prevents erosion. 4. Maintains a good physical condition - good tilth. C. The dust or soil mulch. 1. Formed by tillage. (a) Discuss implements - plow, disk, harrow, roller, cultivator. 2. Depth of soil mulch. 5. Amount of water saved. 4. Some soils form natural mulches - muck and sand. D. Mulches of other materials. 1. How they prevent erosion. 2. How they affect the physical condition of the soil. SOIL TEMPERATURE. A. Affects 1. Chemical. 2 - Biological. 53. Physical. Note,- Develop above and s:.ow how. B. S0Oils receive hear from - 1. Le 3. 4. De Direct radiation of sun. Precipitation and condensation. Interior of esrth. Decomposition of QO. HM. Other chemical reactions. (a) Oxidation. (>) Hydration. C. Factors which influence - 1. Intrinsic factors; (a) Specific heat. (bo) Specific graviey. (c) Heat conductivity. (d) Radiation. (e) Absorption. (f) Organic matter content. (g) Concentration of soil solution. (nh) Evaporation. (i) Nature of surface. (j) Topographic position. (k) Chemical reactions. 1S 14 2. External factors - Meteorological elements. (a) Air temperature. (bo) Sunshine. (c) Barometric pressure. (d) Wind velocity. (e) Dew point. (f) Humidity. (zg) Precipitation. D. All factors may be divided into two classes. 1. Those thet impart heat to the soil. 2. Those that take heat away from the soil. E. Specific heat of soils. 1. Two methods of determining: (a) By equal weights. (bo) By equal volumes. Metnod and results - Michigan Tech. Bul. No.17,pp. 10-12 2. Effect of water as sp. ht. (a) Freezing and thawing of soils. (o>) In summer .5, in winter .25. Results Mich. Tech. Bul. No. 17, p. 13. F. Heat Conductivity of Soils. 1. Order of conductivity of heat in soils. (a) Under lab. (wet & dry) and field conditions - sand clay, loam, peat. (bo) Other conditions - uncultivated, cultivated, sod. 2. Rate of flow of heat decreases for 2 certain distance and then increases. r 3. Effect of water on conductivity. (a) Expells air which is a non-conductor. Ge I. (bo) Brings films closer together. 4. Effect of organic matter. (a) Substance. (0) Greater air space. Results Mich. Tech. No. 17, pp. 14-23. Radiation of Heat. l. Not influenced by color or water content. 2. A ary surface reduces radiation - amount of reduction increases as water content of sub-surface increases 3. Radiating power in dry state - sand, clay, loam, peat. 4. Influenced by chemical constitution and soil covering. (a) Organic matter, mulches, sod, cultivation. Absorption of Heat. 1. Influenced by color, - black, blue, red, green, yellow, white in order. Difference in black and white in colored ssnds about 6° C. 2. Depends upon organic matter and iron principally. Effect of organic matter. 1. The soil temperature increases with the organic matter content to a certain point (about 5% of O. M.) and then decreases. Ce D. Effect of Growing Crops on S0il Temperature. Crops keep the summer soil temperature low, because: 1. The sun's rays are intercepted by the vegetation. 2. Air temperature is low around the plants. (a) Transpiration. (b) Evaporation, . Crops keep the soil covered as a blanket during the cold part of the year, and: 1. Prevent the cold air from coming in contact with the surface soil. 2. The layer may be porous and the layer filled with air - prevents radiotion. Snow has a similar effect es a crop. General aspects. 1. The sod plot warmed faster in spring to about the begin- ning of May, then the temperature fell below that of tle bare plot (cult. & uncult.) and remained so until about the middle of September. Then the bare plots became the coldest snd remained so until the middle of the follow- ing spring. 17 effect of Cultivation on S011 Temperature. A. General Effects of Cultivetion - Mulches. 1. Prevents evaporation of water. 2. Prevents radiation of heat. 3. Cultivated soils hotter on surface on surface. 4. Nulches increase sp. ht. by holdin;j; moisture. B. General aspects. | 1. After thawing in the spring the temperature of cultivated plot rose above the temperature of the uncultivated plot until about the middle of Mey after which the order wes reversed until October. (a) The uncultivated soil absorbed more heat during the day but lost more during the night. x. The temperature of the cultivated surface was greatest as long as the temperature of 20 in. deep remained the same in both soils. When the temperature under 20 in. under the uncultiveted began to rise tne temperature of upper layer of uncultiveted rose above that of the cultivated. 3. The uncultiveted soil was warmer in the day but colder in the night. LE Effect of Soluble Salts on Soil Temperature. A. Solutions of greater densities have the following properties which influence soil temperature. 1. A lower freezing point. <.- A lower vapor pressure. 5. A higher boiling point. 4. A higher surface tension. n DS. A nigher viscosity. B. Rise of temperature. lL. Incresses with tne concentration of solution. (a) Evaporetion decreased. 2. Increase slichtly different for different s-lts. C. Fall of temperature. le. Increases with tre concentration of solution. (a) Freexing point depressed. (ob) Time at freezing point decreases with increase in concentration. (1) Wreezing point stil’ lowered by tne increasing con- centration of theunfrozen part of solution. <.- Supercooling ususlly takes place. So. Decrease slightly different for cifferent salts. D. Thawing. 1. Rate of thawing exactly the reverse of freezing. Effect of Decomposition of organic matter and Manure on S0il Temperature. A. Rise in temperature depends upon; 1. Amount of O. M. in soil. 2. Rate of decomposition. (a) Aeration. (bo) Reaction of soil. B. Rise for different kinds of manure. 1. Order and extent of rise. (a) Horse - 10 tons per A. 30° C. " 40 * now 1.239 * (bo) Cow -10 " noon 249° # " 40 * Hoo 291° 1 (c) Sheep - 10 " noon 20° " 0 40 " * " ; 80 ] General Aspects of SoilTemperature. 1. Make chart to show yearly magnitude. 2. Greatest emplitude in June for 6 and 12 in. in depth - sand, gravel, clay, loam, and peat in order. 53. Fluctuation greater in summer than in winter. ) Soils heated only by conduction in winter. (b) Neated by conduction and absorption in summer. (c) Latent eat of ice prevents fluctuation. (ad) Protected by layer of snow. (e) Sp. ht. 1ess in winter than summer. 4. Temperature of air above soil temperature from April to December, end below the rest of the year. 5. S0il classes cool end freese at avout the same rate of time. 6. Soil clas:es thaw at different periods in the spring. (a) Order of thawing and rise of temperature - (sand gravel) clay, loam, peat. 7. In general we may say: (a) The air temperature tends to vory immensely with the pressure. (ob) The suns’.ine varies directly with the pressures (c) The air tempcrature tends to very directly with the sunshine in summer. . (d) The dew point varies directly witn the temperature. (e) The wind velocity may vary directly with either extreme of pressure. Discuss effect of each element. }~ 0) SOIL BACTERIA. Ae What they are. 1. Bacteria are plants that form the simplest group of fungi and are lacking in chlorophyl. B. What they do in the soil. 1. They effect changes in plant food - mineral or orgamic. (a) Decomposition: (a) In presence of air (bv) in absence of (b) Ammonification. aire (c) Nitrification. (d) Denitrification. (e) And other changes. 2. Fixation of nitrogen in the soil. (a) Non-symbiotic - because they live in the soil itself. (bo) Symbiotic - because they liveon the roots of plants. C. Conditions which effect their growth. l. Bxist in fertile soils in large numbers - mostly at the surface - numbers diminish with depth. 2. present in larger numbers in fertile soils than in unfertile soils. 3. Food: (a) Take in food like plant hairs and require soluble com- pounds containing NCHSO and some amounts of mineral substances. . | (bo) Different kinds.require different foods. (c) Organic matter is the chief food supply. 4. Temperature: (a) Cold decreases action - warming increases action. (ob) Most favorable ranges from 70° to 105° F. - 21° - 40° c (c) Most bacteria are killed at 212° F. - Spores. (d) Dry heat more effective than moist. 0) C3 5. Oxygen. (a) Some bacteria require air (a8robic). They oxydize substances; produce nitrification and sometimes fix nitrogen. (b) Some bacteria cannot live in the presence of air (ana€robic). They take oxygen away from substances and may form gases. 6. Moisture. (a) Some bactefia become dormant when dry. Some are killed. They resume their activity when moistened. (>) Most soil bacteria require certain degrees of moisture for their best action. 7. Light. (a) Sun light kills most bacteria in a few hours - spores. (1) Bacteria in upper layers most affected. (2) Diffused sun light lessens activity. 8. Chemical and physical surroundings. (a) Presence of acids detrimental to bacteria that require alkaline conditions. (bo) Killed by anticeptics, disinfectants, etc. (c) Bacteria do not thrive in pure clay, pure sand or soils filled with stagnant water. 9. Presence of other forms of life. (a) Soil may contain protozoa which feed upon living pacteria. 10. Other conditions - altitude, exposure, plant growth, cultivation, fertilizers, drainage, liming, crop rota- tion, organic matter and shading. (a) Gypsum is favorable to bacterial development. Sodium chloride checks nitrification. D. Products of bacterial action. 1. When by-products reacn a certain concentration tney otten act as poisons. «. The products or some bacteria are poisonous to other kinds. These products may be removed and beneficial action continued. Co Gy 3. Bacterial actions known under general name of fermentation. (a) By-products - sugar, acids, alcohols and soluble nitros gen compounds. (peptones, amino, acids, ammonia, nitrous acid, nitric acid, free nitrogen. ) (bo) Changes produced. (1) Effect changes in plant food, mineral and ogganic. (2) Fixing nitrogen in the soil. E. Changes in the QO. M, of the soil. l. 7. Decomposition; (a) In the presence of air - decay. (bo) In the absence of air - putrefaction. Compounds in the soil. (a) Non-nitrogenous organic sompounds, con. carbon, H & QO, carbohydrates, oils, and organic acids. (bo) Proteins - cont. C, O, H, N, acid sometimes G & P. (c) Mineral - K, P, Ca, Mg, S, Na, & Cl. Decay in the presence of air: (a) A burning or uniting with 0. In detail: (A) Carbohydrates are decomposed rapidly and connected into simpler compounds - oxalic, acetic, etc. acids and finally CO> & Hod. Cellulose: (a) Less readily attracted but products are about the same as carbo. Oils: (a) Are changed into acids and finally COo + Ho0. Organic acids - ultimately Coe - HoO. Proteins form simpler N. compounds. (a) Albuminoses or proteoses. (b) Peptons or peptids. (c) Amino acids - finally into NHz or N. The C, H, 0, to CO2 & Ho0, the § to S03, and P to P205. tC) > 8. Minerals - mainly the form of phosphates, sulphates, car- bonates, chlorides. F. Decomposition in absence of air: - putrefaction, in soils, — humification - different kinds of bacteria. 1. Process much slower - as shown by differente in depth, looseness, outside of a particle, in well drained or water-logged soil. 2. Chemical changes are less complete - some COo & H50 & N are set free but the largest portion of the 0. M. is very complex, is dark-colored and forms humus in the soil. 3. Humus not é@asily decomposed by bacteria even when exposed to air. 4. Offensive and poisonous compounds - many are bad smelling and poisonous - HoS, PH3, CH4, Skatol and nidol. 0. Difference in gases formed - air, C02, H20, SOo, NHz, N - absence of air, small amount of above and HoS, PHs, CHg. G. Ammoniafication - conversion of Org, N.into NHz - by ammonify- ing bact., some a@érobic some anaerobic - depends upon a variety of conditions as have been described. Such bact. found in air, rainwater, stables, manure, and surface soils. Important to agriculture. COH4No*+2Ho0 2 COo+2NH34H0O = (NH4)2C0z Nitrification - forming HNO3 Cs, 1. Chemical changes - two - two kinds of bacteria. (a) NHz to HNOo (bd) HNOp to HNOZ (c) NHz + 30 » HNOo + H50 (da) HNOs + O = HNO3Z Cac0O3 = Ca (No3z)2 + COg + Ho0 (e) 2HNOs + KoCOz = 2KNO3 + CO2 + HO NaoCOz = 2NaNO3 + CO, + H90 MgCO3 = Mg(NOz)o2 + COg + Ho0 Nitrification is an oxidation process and results in produci ng an acid. Bact. found in all cuttivated soils, water,manure, and séewage. H. Conditions that influence their work. 25 1. Location - upper layers 2/3 first foot, rest 2nd foot - depth depends upon looseness and warmth. 2. Moisture - does not take place in dry soil - not active in water-logged soil. 5. Food - NHz and the N of O. M. - air excess of sol. N. or carbohydrates prevents growth, this rarely occurs in a cultivated field, but may in gardens and green housés. Sewage-irrigation harmful. A certain supply of minerals necessary. " 4. Oxygen - air necessary in the soil - may be too fast in sandy soils - slow on heavy land - cultivation promotes. 5. Temperature - most active 54° - 999 F., (12° - 37° c.) increases with rise and decreases with fall of temperature more in summer than winter - earlier in spring on warm soils. 6. Light - darkness is best for activity - not found close to surface where soil is bare - more active in shaded soil - On warm nights, under boards and stones. 7. Non-acid condition - acids are very injurious - soon die in excess of HNoz - not active in acid soils - soil must be made alkaline - carbonates are best. I. Denitrification - reverse of nitrification - reduction - 3 form 1. Destructive Nit. - HNOz to HNOo to N - lost. 2. Partial decomposition - HNOz to HNOo to NH3 - May go to 5. Conversion to 0. N. Comp - HNOg to proteins - May go go HNOz again. Takes place under two general conditions: (a) Lack of air in the soil - some 0 is required and if ther is no air it is taken from soil comp. cont. 0 - cult. diminishes - greatest in heavy soils - N. from fertil- izer may be lost in this way. (bo) Too much 0. M. in the soil - sol. condition - some N. fwom manure or green manures may be lost. Bacteria use N. and they may change it from sol. to insol. forms in the soil - may be beneficial or harmful. Nitrifica- tion does not increase the total amount of N. in the soil. J. Fixation of atmospheric N. 1. Two kinds of bacteria: (a) Those that live in the soil itself - Non-symbiotic. (bo) Those that live on the roots of plants - symbiotic. 2. Non-symbiotic: (a) Soils naturally increase in N. content - examples (bo) Commercial ventures - "Alinit". (c) These bacteria require: 1) A generous supply of carbohydrate material. 2) The presence of CaCQz or MgCO3 is important. 3) Some soluble phosphate is needed. 4) Organisms are injured by an acid condition. 3. Synbiotic: (a) Long noticed that legumes were beneficial tosoils. (bo) Caused by certain kinds of bacteria - N. (1) Root nodules and bacteria. a) Discovered 25 years ago. b) Common in soils, waters, etc. c) Make their way into the plant root. There they multiply rapidly and perform their work. (ad) Found only on the younger parts of roots. When the parts grow old the nodules decay and the bacteria go back to the soil. (2) Relation of bacteria and legumes: (a) One of mutual helpfulness. (b) Tre bacteria use carbohydrates from the plant and give the plant N. in return. (3) Amount gathered by bacteria: is 100# to 2004 an acre in a favorable season. b) May be below 50# in unfavorable seasons or conditions. (c) In some cases the amount of N. remaining in the stubble and roots of a crop is equal to the amount removed from the soil by the crap. In this case no N. is taken from the soild (ad) Under favorable conditions one-third of the N. used by the crop may be taken from the soil and 2/3 from the air. (e) May not increase the N. in the soil but usu- ally increase the feeding value of the crop. (4) Kinds: is Many different kinds. b) Those that grow @n a certain kind of legume are best for that plant. (c} Some combinations - alfalfa, bur clover, sweet clover, white and alsike clover and red clover: the common vetches. (5) Conditions of action of legume bacteria: a) Same as those that favor nitrification. b) CaCOz, O.M., air, and moisture, a supply of carbohydrates and mineral food. (c) Use available N. compounds in the soil in pre- ference to free N. (ad) Formation prevented where there is a supply of available N. (6) Independent action of legume bacteria. (a) May act independently of the plant but the amount of N. formed is small. (7) May be found on other plants. (a) Found on alder, New Jersey tea, buffalo berry, Silver berry, mountain balm, sweet fern (corn ?). These are not money plants but may be beneficial on unused lands. K. S011 inoculation for legumes. ‘1. In many cases the bacteria are present in soils, and . always where the crop has been grown for a time - cloves alfalfa, and cow peas in their localities, alfalfa and cow peas and vetches in Michigan. 2. Bacteria may be supplied by inoculation. Two ways: (a) By using soil. (b) By using pure cultures. (1) By using soil: a) Probably best method - how to do. b) Remove the upper layer - 200# - 500# per A.usé. c) Beware of weed seeds and plant diseases. ad) Soil may be treated with water and tne seed soaked in the extract. (e) Glue and soil have been used on ‘large seeds. (f) Root nodules may be used. (2) By pure cultures: One kind of bacteria. Difficult to keep them alive and vigorous. What inoculation does. | Only one factor of crop growth. Good results may be obtained: (a) Where the soil is,in good condition and legumes do not do well; ‘P Where the roots do not have the nodules; c) Where legumes are grown the firstt ime. 200 ® 6 (3) Soil inoculation usually fails to produce results: bd) Where the soil is acid. c) Where the supply of K and P is deficient. d) Where there is too much sol. N. in the soil. e) Where the soil has a poor physical condition. f) Where seasonal conditions are unfavorable. ) Where the specific bacteria are present. | L. Changes in Mineral Constituents by Bacteria. The products of bacteria comprise CO5, Nitrous, Nitric, Sul- phuric and organic acids. These acids bring about the following changes: 1. Calcium and other insol. carbonates are made soluble. 2. Insol. phosphorous compounds are made soluble. 3. Bacteria use minerals which are returned to the soil ina soluble condition. 4. Insoluble K. compounds are made soluble. o- L. is changed to HoS and finally H550,4 or reverse (mucks). 6. CaSOq may be changed to Ho8 by. anaerobic ewacteria. TILLAGE. A. Tillage refers to working the soil with implements. B. Objects of Tillage: 1. To change the structure of the soil. (a) To control soil water, aeration, temperature. 2. To bury rubbish. 5. To cover seeds. 4. To kill weeds. 5. To make plant food available - nitrates. Ce. Tillage implements. 1. Many kinds. 2. May be divided into two groups. (a) Thoee which loosen soil structure. (bo) Those which compact soil structure. D. The Plow 1. Object of plowing: (a) To change soil structure. (ob) To bury weeds. 2. Two general types: (a) Moldboard plows. (bo) Disk plows. 3. Moldboard plows. (a) Produce a shearing action on the soil. Explain. (bo) Three general types. (1) Long, sloping moldboarda - (a) Cuts a clean furrow and turns it over com- pletely to bury weeds and manures - pulver- izes little. (2) Bhort, steep moldboard. (a) Thoroughly pulverizes soil. (3) Intermediate moldboard. (a) Better for soils that pulverize easily because of less draft and wider furrow slice. (>) May be better on heavy soils when necessary to lighten draft. (c) Better for soils which tend to clog on the moldboard. (4) There is always a shape of moldboard, condition of moisture and depth of furrow for best condi- tion of tilth. (a) The more moisture, the steeper the moldboard, the deeper the firrow, the more the soil will be puddled. (b) Therefore, for soil too wet, use less steep moldboard and plow as shallow as conditions will permit. (c) If soil is somewhat dry use steeper moldboard and plow deep. (d) When soil bs too dry no shearing takes place. (e) The steep moldboard works best with soil a little dry. (5) It is not desirable to turn the furrow slice over fiat. (6) A general relationship between width and depth of furrow is 2 wide to 1 deep. (c) The plow should be adapted to the soil. (1) Coarse grained, porous soils should be plowed with a steep moldboard, a little over wet, and as deep as conditions will permit to break down granulation and secure closer texture. (2) Mellow soils may sometimes be plowed with a less steep moldboard and with a wider furrow. (3) Fine grained, heavy soils need the less steep moldboard and when the soil is a little dry,on these soils the moldboard should be as steep as possible consiétent with the draft to get the most pulverizing action. ol 4. Disk plows. (a) Turns and pulverizes the soils. (b) Lighter draft for amount of work done. (c) Effective on hard dry soil and in burying weeds and manures. Draft of plows. (a) See King, pp. 243 - 246 6. Care of plows. (a) Surface of moldboard should be kept polished. (o>) Plow should be kept in proper adjustment. King, 248. 7. Jointer attachment. (a) Helps to bury trash better. (bo) Useful in plowing under crm ps and when sod groad is fitted for immediate use. 8. Subsoil plow. (a) Follows ordinary plow. (bo) May puddle soil. (c) Best in fall in humid climates. (ad) Of more benefit in arid climates. 9. Depth of plowing. (a) Must use judgment in determining. (o) In humid climates it is best not to go into the sub- soil. If necessary the subsoil should be turned up gradually. (c) 6 to 7 inches - less for small grains. (d) Should be varied to prevent "plow sole*, 10. Time of plowing and after treatment. (a) In spring. 1) Light soils. 2) Effects of mulches on heavy soils. 3) If plowed too wet, roller should not be used and the harrow only after a time. Ze. Ok be If plowed dry harrow should be used immediately. 5) If for cultivated crops to be planted later and plowing in good condition it should be left rough. (6) Mulching plow land. (bo) In fall. 2) Heavy soils. 3) Burying manure and cover crops. A Lessens spring work. a) Deep fall plowing best or early spring. b) Roller should be used. c) Followed by disk. Barly fall plowing. 5) Action of frost, etc. Should be left with rough surface. @)) On THE ROLLER. A. Qbjects of rolling. 1. To compact soil after sod plow and where crops are plowed under. 2. To crush lumps. 5. To break crust on surface. 4. To cover seed when sown broadcast. 5. Weight should be 100# to running foot with a diameter of 2 feet. B. Kinds of rollers. 1. Smooth. 2. Corrugated. 53. Subsurface packer. C. Smooth roller. l. Rolling fields after seeding. 2. Stops excessive ventilation in soils - this may be beneficial or injurious. 5. Harrow should follow roller. 4. Should not be used on heavy soils when they are wet especially after seeding; may also stop nitrification. D. Corrugated roller. 1. To break crusts on small grain fields especially if the soil surface is rough and somewhat dry. E. Sub-surface packer. 1. Useful in the conservation of moisture. THE HARROW. A. Objects of Harrowing. 1. Ze Oe 4. Killing weeds. Saving moisture by soil mulch. Smoothing the s0il surface. Preparing the seed-bed. B. Kinds of Harrows. 1. Re 3 4. 5. 6. Ve Di sk. (a) Smooth disk. (b) Spike disk. (c) Spading disk. (d) Cutaway disk. Springtooth. Spike tooth. Weeder. Planker. Acme. Meeker. C. Disk Harrow. l. Re Se A. De Very useful where soil is drying out and there is not time to plow. May be used on alfalfa. Preparing plowed land for a cultivated crop, especially when land is plowed in fall. This harrow thoroughly pulverizes the soil. May be used in place of the plow where small grains follow a cultivated crop. Springtooth harrow. l. Useful in preparing plowed land for a cultivated crop, especially when the ground is rough and stony, or on new land. | Be Fe Spiketooth harrow. 1. To break crusts on small grain fields, where the soil surface is smooth and not too heavy or by driving across the ridges. 2. May be used on alfalfa alone and after the disk. 3. May be used to advantage on plowed land when used after the springtooth or disk. 4. Useful in killing wees before the crop is up, and where the weeder is too light. 5. Where soil is mellow this type of harrow may be used after plowing - covers ground fast. The planker. 1. Crushes lumps and leaves soil surface smooth without | firming it. Weeder. 1. Very useful to destroy weeds when they are small, and on light soils before the crops come up. Acme. 1. Efficient pulverizer where ground is free from stones. Meeker. 1. Pulverizes hard ground. CULTIVATORS. Ae Objects of cultivator. 1. Same as tillage in general B. Kinds of cultivators. 1. Spring tooth shovel cultivators. 2.- Rigid tooth shovel " 5. Disk. 4. Rigid tooth with long, flat shovels. 9. Garden cultivators. C. General considerations. 1. Cultivator shovels should be small and many rather than few and large. 2. Rigid tooth cultivators usually do better and more uniform work than spring tooth. 5. Spring tooth cultivators are better adapted to stony soils. 4. Disk cultivators good for covering weeds in the row. 0. Flat bladed shovels are good for shallow surface cultivation. DRAINAGE. A. Drainage refers to the removal of excess water from surface soil. B. What drainage does to soils. Ll. Le Be 4. 5. 6. 7. 8. 9. Increases room for plant roots. Makes more water available for the plant. Soils are made warmer. Aeration of soils is increased. The physical stmucture of heavy soil is greatly improved. Action of micro-organisms enhanced. Allows soils to be worked earlier in the spring. Lessens surface washing. Drainage prevents "heaving". C. Kinds of drains. 1. we Se Open ditches of many kinds. Tile drains. Miscellaneous - plank, stone, pole, brush, etc. D. Tile drainage. 1. ny ie A good drain tile should: (a) Be hard burned. (b) Contain no limestone. (c) Have straight ends. Depth of tile drains. (a) Depth of drain is determined largely by: the (1) Kind of soil. - The finer the soil the deeper the drains. 2) Fall or gradient of drain. 5) Amount of earth to be removed. oe 4. 5. 6. rr $3 @- iw (o) For most cereal crops the water table should be kept from 24 to 3 ft. below the surface. Fruit trees and deep-rooted plants require greater depth of soil. (c) 3 ft. is the usual depth for the tile drains, 4 ft. is considered deep drainage, and 2 to 2% ft. shallow drainage. Distance apart of drains. (a) Depends upon: (1) Porosity of soil - The finer the soil the closer the drains. (2) Depth of drain - The deeper the drains the farther apart they may be placed. (3) Rainfall. - Drainage should be complete enough to remove the excess of water from a culti- vated crop in from 24 to 48 hours. The more reinfall the more tile drains. (4) Tile drains are usually placed 50 - 100 ft. apart, more or less, depending upon the actual soil conditions, - 100-150 for sandy soils, 60-70 for muck, 40-50 for clay. How water enters the tile. (a) If the tile walls are porous, like cement tile, some water will seep througn them, but most of the water enters the tile drain at the joints between the tiles. Fall or gradient. (a) A tile drain should have a certain fall to allow the water to run through it freely, - 2 in. fall in 100 ft. is the least allowable for good drainage. (b>) Fall shouls be as uniform as possible. (c) Changing from a greater to lesser fall is undesirable. (ad) A change from lesser to greater fall may be de- sirable. Size of tile to use. (a) There are many factors involved and the proper (c) (d ) (e) (f) (g) (h) size is hard to determine. Should be large enough to give good drainage in 24-48 hours after a heavy rain. Larger tile should be used when single drains are laid in irregular order. The greater the fall the smaller the tile may be. Doubling the grade increases the carrying capacity about 1/3, but small tiles have greater friction than larger ones. Tiles smaller than 3 in. readily fill with sediment and are not recommended. Size of tile depends somewhat upon the length of line - 2 in. tile should not be laid in lines of over 500 ft. in length and 3 in. tiles in lines more than 1000 ft. long, 4 in. 1500 ft., etc. The flow of water through tiles varies directly as the square of the diameter, not considering friction. C. G. Elliott's figures on size of tile to give complete drainage: 3 in. tile will drain 5 acres. 4 A " " " 12 “ 5 On " " " 20 " 6 " " ‘1 40 " 7 ‘1 " " " 60 " (a) () (c) (a) Should be above the water line in a larger ditch or strean. Should be protected with masonry and screen. Best to have outlet point down strean. Glazed tile is best where there is danger of breakage by frost. 40 8. Silt basins. (a) Main purpose is to catch silt and prevent the drain from clogging. (o) A silt basin should be placed in any long line of tile. (c) Or where two mains come together. (a) Or at a bend in a long line of tile. (e) Or where the grade changes from greater to less fall. (f) Or where surface water enters the drain. 9. Junctions. (a) It is well to have the laterals dump their water into the main at the top if the grade permits. (b) A good junction is made by knocking a hole in the side of the main and inserting the first tile of the lateral. ) The seeds produced under these conditions are apt to be improductive or even sterile. 40 (3) Maturing of plants: (a) Retards maturity by continuing growth - growth . in stems and leaves instead of seed and fruit. (b) In case of grain crops the excess of N. tends to cause lodging, due to the long-jointed, soft, weak stems. (4) Effect on color. (a) Usually causes a deep green color in tne foliage when present in quantities. (>) When plants cannot get N. they cannot make chlorophyll. (c) Large quantities of N. in soil cause green apples. (5) Regulation of Plant Growth: (a) The use of KPo0, regulated by N. supply. (6) Effect on quality: (a) Large applications of N. cause softness of tissue, but the keeping qualities are gen- erally impaired, - garden crops. (b) Too much N. makes wheat lighter, the barley berry is lighter and thick skinned and not satisfactory for malting murposes. (7) Power to resist disease: (a) An excess of N. makes plants less resistant to diseases - nursery stock, greenhouse crops, rust on wheat and oats, etc. (bo) Shrubbery and young trees that have been forced too much are less resistant to cold weather. (8) Effect on composition: (a) An increase of N. in the soil causes more to go into the grain. 2. Phosphorus. (a) Brfect on germination. (1) P favors rapid development of the young seedling by stimulating the growth of the roots and thus giving the young plant a good start. (bo) Bffect off early ripening. (1) P favors the early ripening of crops. The form- ation of the grain begins sooner. (c) P. Increases the proportion of grain to straw. (d) Abundance of P causes a decrease in percent of N in the straw. (e) Protoplasm cannot be formed without P. (f) P is absorbed by soil and very little is lost by drainage. 3. Potassium. (a) More abundant in older parts of plants. (bo) K is necessary in order that the plant build up carbohydrates. (1) The starch is first produced in the leaves in an insoluble form, but is changed to the soluble form and transferred to the different parts of the plant. K and Ca are supposed to be directly concerned in this. (c) When K is deficient the stems are weak and brittle - K is mostly in stems and leaves. (d) K compounds are supposed to be requisite to the nor- mal development of the fleshy portions of fruits. (e) K compounds supposed to keep plant cells turgid. (f) K is present in sour plant juices, combined as an acid salt with tartaric, oxalic, citric, etc., acids. (g) An excess of K prolongs growth of stems and leaves - Bame as N. (nh) K enables plants to withstand fungous diseases: (1) In absence of K wheat and oats are more liable to rust. Grasses are affected by fungous diseases. The effect is greater with excess of N, (i) Bffect on leguminous crops. 1) Produces a favorable effect. 2) Promotes growth of bacteria. 3) Effective on sandy soils. (j) Absorbed by soil. Z t - ) en (k) Gramineous plants require less potash than legumes. 4. Calcium. (a) Aids in the growth and strengthening of cell walls. (o) Similar to K in transferring starch. (c) Aids in development of root hairs. (ad) Found in plants where the greatest vegetative activ- ity is taking place as oxalate chiefly - sometimes carbonate, phosphate, and sulphate. (e) Large quantities lost in drainage waters. (f) An excess tends to cause Mal-nutrition. 5. Sulpnur. (a)Constituent of protein - action important. (b) Constituent of odorous oils - mustard oil, as in mustaré, horse radish, turnip, cabbage, etc., and garlic oil in onions, garlic, and leeks. (c) Occurs in leaves and stems. 6. Magnesium. (a) Abundant in seeds and fruits. (bo) Poisonous when in excess. (c) Mg is concerned in the transfer of Pos and starch in plants. 7. Iron. (a) Found mostly in leaves. (bo) Absolutely necessary to the formation of the green ° coloring matter in plants. 8. Oxygen. (a) About 42% of dry matter. (bo) Comes almost entirely from water. (c) Free O of air used in germination, flowering, etc. 9. Carbon. (a) Most prevalent of all elements - 45% (ob) Comes from COo of air. (c) Constituent of all plant compounds except water. 10. Hydrogen. (a) Comes from water. (bo) Distributed throughout plant. BE. How plants take and use their food. 1. Plant cells as manufactories. (a) A plant may be considered as a factory made up of small fooms - cells. Cells contain protoplasm, the living part. <2. How plants obtain and use carbon. (a) Nearly one-half of the dry matter is carbon. (b>) Comes from the CO of the air and is absorbed by the leaves. (c) Depends upon chlorophyl and sunlight. (d) Assimilation or fixation of C. photosynthesis. (e) Depends upon intensity of sunlight, temerature, water supply, CO» in the air, number of pores on the leaves, the suppty of mineral plant food. 3. Relation of roots to food supply. (a) The plant food from the soil enters the plant by the roots. (b) In solution through the root-hairs. (c) Root-hairs come in close contact with the soil particles. (ad) Roots excrete acids which may nave some solvent power. 4. Absorption of soil solution. (a) Osmosis. (bd) When the soil solution becomes concentrated enough the water may pass out of the plant. (c) 1 pt. in 500 is the limit of concentration (?) (d) Indications - Leaves turn yellow on edges, become spot- ted, drop off, growth is checked, dwarfed, shortened, leaves become puckered and twisted. 47 5. Turgor of plant cells. (a) Intimately connected with osmosis. (bo) Evaporation may concentrate the soil solution. (c) Plants wilt after a heavy rain - why ? (d) Too heavy an application of fertilizer may cause plant to wilt. 6. Selective power of plants. (a) Plants use some foods in greater quantities than othes. (bo) The food is removed from solution when it enters the cell. ' 7. Forms of constituents used. (a) NaNOz does not necessarily pass into the plant. (b) The NOz may be taken in and Na rejected. The Na might combine with COo and form NaoCOz and make the soil alkaline ? NaHCO3. (c) In case of KCl or KpS04 the K may be taken in and the acid radicle rejected and the soil become acid. (ad) Bach substance is used more or less independently of the others. 8. Feeding power of crops. | (af) Ability to absorb plant food from the soil. (1) Depends upon area of root hairs and the activity of the chemical: processes of the plant - chiefly. (excretions) (ob) Corn, oats, cabbages, often grow well on soils where wheat and onions fail. 9. Effects of plant food distribution on root growth. (a) Roots grow in the direction of food supply. (vo) Shown by experiments. (c) Plant food should be mixed thoroughly with the soil. n> ~~ 1, AMOUNTS, LOSSES, AND GAINS of PLANT FOOD in SOILS. A. Amount of Plant foods used by Principal Crops. (Chart) References - King's PHYSICS OF AGRICULTURE, p. 97. SOILS - Lyon & Fippin, p. 282. SOIL FERTILITY AND PERMANENT AGRICULTURE, Hopkins, p. 154. B. Amount of Plant Food in Michigan Soils. 1. See table of analyses of Michigan soil types. (Chart 1.) 2. Consider what plant foods are lacking in Michigan soils. (Amounts necessary for fertile soils - k 24,000# per A. ft. P 2,000#, Ca. 12,0004, N 5,0008. ) C. Losses of plant foods from Soils. 1. Removed by growth of crops. (a) Different crops use the same foods in different amounts. (b) Food removed by crops - amounts. (c) Where the leaves and stems go back to the soil not so much plant food is removed. (Chart systems of farming. ) (ad) A Crop may be fed and the manure put back - loss small. 2. Loss by leaching. (a) Carried away by leaching and surface washing. (0) Some elements absorbed - some are not. 1) Amount and time of rainfall. 2) Lack of O.M. in the goil. 3) Form of plant food influences amount of loss. Remedies - ‘ O. M. b) Crop. ec) Terracing hillsides. 35. Loss by mechanical agencies. (a) Soil particles carried away by the water, and wind. (bo) Affects the physical condition of the soil. 49 Remedies; Same as (7-5-2) including wind breaks and mulchings. 4. Loss by conversion into gases. (a) N. is lost in this way as free N. and NH 3. (o) Burning the soil. 5. Plant foods are held by the soils by: (a) Chemical fixation. Explain. (o) Physical fixation. " 6. Kinds and amounts of plant food removed from the soil. (a) The blowing and washing of the surface soil removes all kinds of plant foods. (b) Calcium compounds - loes 500# - 1000# per A. per year, as calcium carbonate (acid). Ca is converted into sol. forms by acid (mineral and organic) sub- stances, bases, formation of nitric acid in the process of nitrification. (c) N. compounds - lost in the form of nitrate - 25# - 50# per A. per year. (d) P. compaunds - enly small amounts lost. - 400000 tons for U. S. annually. (e) K. compounds - may exceed 104 per A. per year, usually less - 3,500,000 tons for U. S. Loss is probably greater in the particles carried away, except lime, than leaching. D. Gains of plant foods by soils. Ll. Application of fertilizers: (a) Depends upon the composition of the material added. 2- Plant food in rain water: (a) Dew and rain bring 3 - 104 N annually. 4 - 54 in the form of NH3z and N as nitrate. (b>) Depends updn, rainfall, cities, climate, etc. 00 3. Plant food added by means of bacteria. (a) N. 4. Plant food from subsoil. (a) By growing deep-rooted crops. (ob) By increasing the depth of plowing. (c) By movements of the soil water. (d) By burrowing animals. 5. Plant food from feed-stuffs. (a) In the increase of manure. ol FERTILIZERS - KINDS AND PRACTICAL APPLICATION. A. Principal carriers of nitrogen. 1. Mineral Products. (a) (») Nitrate of soda - 15-16% N. supply comes chiefly from Chili. Minor sources Egypt, Peru, Bolivia. Soluble form, directly utilized by plants. Application 100 to 400 los. per A. Should be applied as top dressing when plants are dry. May burn leaves when wet. Should not come in contact with seed. Tends to pro- mote tellering when used early in spring. This may reduce yield of grains but good for grass. Tends to gradually correct acidity. May injure structure of heavy clay soils when used frequently. The residual soda may liberate and replace potash. May injure highly basic soils. May cause a more economical use of phosphorus and potassium by the plant. Lessens loss of carbonate of lime from soil. (200 = 300# per A. per an.) Yields quick returns on the in- vestment. Sulphate of Ammonia - 20.2% N. Supply mainly from the destructive distillation of coal in coke ovens, blast furnaces, gas workdé, etc. Must not be mixed with alkalime substances. The ammonia is readily absorbed by the soil and less loss from leaching results. Takes lime from soils (NH4)o9S04 - CaC0z a (NHg)5CO3z + CaSO4g + He0. Nitrogen of (NH4)2S04 is fixed by micro-organisms. About .9 as efficient as (c) (f) ceo we i NaNOz. Increases the toxic effects of acid soils. Not always detrimental to plants adapted to acid soils. May suspend bacterial action when used in large amounts. Liberates bases from their combina- tions in the soil. Fertilizing effects not perman- ent. May cause imjury on light limestone soils. Calcium Cyanamid - Comm. 10 - 16% N. Made by pass- ing N. gas over calcium carbide at a high temper- ature. CaCo + No = CaCN2 + C. Action in soil, CaCN2 ~ H20 » Ca(OH)o - CO(NHe)2. Slowly decomposes wien exposed to air. Compares with sulphate of anm- monia on heavy soils. Toxic to young plants by formation of dicyanamid. Should be applied some time before seeding or planting. Good for acid soils on account of the Cad. Calcium Nitrate - 13% N, 25% CaQ. Made by passing an electric spark through air. Very hygroscopic. Good for soils deficient in lime. Less valuable on limestone s0ils and for plants that do not require lime. Under favorable conditions produces results comparable with nitrate of soda. Potassium Nitrate - About 11% N. From India and Cape Colony. Often made artifichally in nitre beds. Expensive but may be economically used on garden crops or when other forms of N are high-priced, or transportation charges high. Chlorine is avoided when this compound is used. Ammonium Nitrate - 35% N. Expensive but freight charges low. Excellent fertilizer. ze Animal products. (a) Dried Blood. - Red, 13 - 14% N. Dried in vacuo. Black, 5.5 - 12% N. Dried at high temperatures. Blood contains .5 - 1.5% PoOs and .6 - .8% Ko20. Contains considerable moisture when finely ground. One of the best organic fertilizers. Does not work well on an acid soil. (bo) Dried meat or meal - 10 - 144 N, 13% Po0s5. Next to dried blood in efficiency. (c) Horn & Hoof Meal - About 124 N, 5.5% Po05. Not as good as blood and meat meal but better than leather, etc. (ad) Leather meal, wool and hair waste, feathers, etc. Contains varying percentages of N (5 - 19%) and Po05 (.5 - 3%). All low grade fertilizers. Some may be improved by steaming and other treatments. Wool waste. should be spread broadcast and plowed under. §ghoddy and felt wastes highly esteemed for grapes, other small fruits and hops. WN becomes gradually available. 1 - 2.5 tons equal to 20 tons manure. Good effect on physical condition of soil. (e) Fish Scrap - About 3 - 10%4N, 6 - 14% Po0g. Prin- cipally from fishing industries. Sometimes treat- ed with HoS04. May be applied directly to the soi when easily obtained. Best adapted to warm, moist climates and on sandy or open soils. ‘(f) Bone tankage - 4 - 12% .N, 7 - 20% PoOs. Rendered 54 and steamed bone, meat, etc., from packing houses. Value depends upon degree of fineness. Best method is to mix well with thelsoil. (g) Natural Guanos - Contain varying percentages of N & P505- (3 - 154 N), (12 - 25% P9005). Excrements and remains of birds and marine animals. Chiefly from main land and islands of Peru. Does nothave a long-continued or marked influence on the physi- cal character of the soil. Often treated with Ho804- Raw guano readily loses ammonia and should be mixed with the soil. The treated guano is ideal for top-dressing. Should be balanced by introducing lacking elements. Bat guano - 1 - 12% N, 2.5 - 16% PoO5. Found principally in caves and grottos in different parts of the world. Needs supplementing. Fish guano - 7 = 8%4N, 9 = 10% P505- Use depends upon soil conditions favoring decomposition. Should be supplemented with forms Of PoO, and Ko0. 3. Plant Products. (a) Garbage Tankage - 2.5 - 34N, 1.5 - 3%, PoO5, 7 1.5% Ko0. Kitchen wastes chiefly. Fertiliz- ing value low. Usually steamed. (bd) cotton-Seed Meal - 4 - 74 N, 2.5% Po0s, 1.7% KoO. Refuse from cotton seed oil manufacture. Used ex- tensively in South and East on sugar cane, cotton and tobacco. In North usually fed to dairy ani- mals and manure applied to the soil. “ ey (c) Linseed Meal - 4.9 - 5.84 N, 1.8% PoOs, 12% Ko0. Refuse from linseed oil factories. (ad) Castor Pomace - 5.5 - 5.75% N, 1.5 - 2.25% PoOs, 2% KoO. Refuse from castor oil presses. (e) Sea Weeds - .17 - 1.35% N, .05 - .25% P05, .16 - 1.65% Ko0. Applied economically only where found. Some decompose readily and may be used in small amounts as autumn and winter top dressing on grass. Best plowed under. Give smooth potatoes, sometines of inferior quality. On account of the adhering | snlt they may be injurious to hops, the burning quality of tobacco, and may depress the sugar content of beets Often leached by rains before applied to the soil. Not a balanced fertilizer. May introduce lime in shells attached. Are free from weed seeds. Sometimes composted with lime or manure and soil. (f) Peat and muck - 1 - 4% N. Valuable on light soils that require organic matter. 4. Miscellaneous products. (a) Soot - .5 - 6% N. in form of ammonia. From con- bustion of coal. Improves physical camdition of clayey soils. Color supposed to have a beneficial effect in warming the soil. B. Carriers of Phosphorus. 1. Mineral products. (a) Floats - (Name applied to finely ground raw rock phosphate). South Carolina rock - 26 - 28% Po0s. O6 Found on land and in the beds of rivers. Florida phosphates - 18 - 30% PoQs. Varies greatly. A whiteish product found on land and in river beds. Canadian Apatite - Best grades 40% Po0s. A crystalline rock, expensive to mine. Tennessee Rock - 30 - 32% PoQs and exists in veins and pock- ets. Floats especially beneficial on peat or muck soils, and upland soils rich in organic matter. Not advisable on light, sandy soils low in organic matter. Often used in stable gutters with good results. Should be mixed thoroughly with soil. Best on those plants which have a long season of growth. Not good for plants having a low feeding power for P - turnip, cabbage and similar plants. Might be used with limestone for plants desiring alkaline soils. (ob) Treated Rocks - Acid Phosphate - made by treating phosphate rock with H2804. 14% P205. Cagz(PO04)o + 2H,S0, = 2CaS04 - CaH4(P04)2. In the manufacture of superphosphate. More HoS@4 is used and free phosphoric acid is liberated. Caz(P04)5 + 3H2804 = 5Cas0, - 2HzP04- Double superphosphate is made by treating low grade rocks with Ho804 as for super- phosphate, pmrifying the H2P0q4 and using it toltreat a high grade phosphate rock. Caz(PO4)o + 4H3P04 = 3CaH4(P04)o. The object of these treatments is to make the P more soluble. Monocalcium Phosphate easily reverts in the soil. May form compounds wih 57 iron and aluminum. Lime should be added as the Calcium phosphates are the most soluble. P. fix- ation in the soil rapid, and very little leaches away. The upper nine inches of soil holds nearly all of applied Po0s5. Superphosphates should be applied to the soil some time before seeding. Do not have good effect on acid peat or upland soils. Have a flocculating effect upon the soil. Very good on Calcareous soils for turnips. Acid soils should first be limed on fertilized with wood ashes Residual effects of acid phosphates long-continued. Turnips, cabbage, Brussels sprouts, kale, kohl-rabi, cauliflower, lettuce, beets, spinach, radish, sugar beets and potatoes. Soluble phosphates good when rainfall is light. They greatly hasten maturity. (c) Basic Slag - 12 - 28% Po0s. A waste product from the manufacture of steel. Material important, 80% should pass 100 mesh sieve. Contains 40 - 60% Cao. Needs moisture to become available and is good on clay, peat, or muck soils. Improves physical con- dition of clay. Good for sandy soils except in case of drouth. Ideal use is on acid soils. Should not be mixed with organic nitrogenous mater- ials or ammbnia compounds. 2. Animal Products. (a) Bone phosphates - 1 - 34 N. 20 - 30% PoO5. Chiefly from packing houses. Sometimes steamed and some- times treated with Ho5S0,4. Ideal soils for raw or bE steamed bone are sandy or gravelly, although they should not be too dry. Acts slowly on heavy soils. Lasts in the soil. Much used before seeding land to clover or grass, fruit, hops, and crops which require a long season of growth. Dissolved bone black - waste boneblack from sugar refineries treat- ed with HoS04. Bone tankage - See A-2-(f). (>) Fish scrap - See A«2-(e). (c) Guanos - See A-2-(g) C. Carriers of Potassium. 1. Ashes - wood-- 3 - 8% Ko0, 30 - 25% cad, 3 - 4g MgO, 1 = 2.5% Po05. Cotton-seed hull - 10-42% Ko0, 3-13% P5005, 9% CaO, 10% MgO. Corn cobbs - 50% Ko0. 2. Tobacco stems. 3.76%-8.82% KoO, also rich in N. 3. Sea weeds. See 9 - 3 - (e). 4. Potassium Nitrate - 44.5-45.5% Ko0, 12-14.5% N. Valuable when necessary to avoid sulfuric acid and chlorin. 5. Potassium Carbonate - 90% Ko0. Supply chiefly from Russia. Good when sulfates and chlorides are ob- jectionable. More applicable to acid soils. May dissolve humus and cause deflocculation. 6. Kainit - about 12.4% Ko0. Contains chlorides and sul- phates. Much used in making complete fertilizers. Not good for sugar beets, tobacco, or potatoes because of the harmful effect of chlorine when kainit is applied the same spring. Not harmful if applied the preceding year. Og 7. Muriate of Potash - 48-50% Ko0. 8. Sulphate of Potash - 47-48.5% K.0. 9. Double sulfate of potash and magnesia or double manure salt - 25-27% Kp0, 34% MgSO,. May be used where sul- fur is needed and chlorin is to be avoided. Should not be used on soils rich in magnesia. 10. General considerations on use of potash fertilizers - The use of chlorin increases need for liming. Ca @ Mg chlorides are formed, are toxic and leach away. Held tenatiasly by soils except perhaps in case of very light ones. KoO remains close to the surface. Very veneficial to legumes. Act best in wet seasons. BARNYARD MANURES. A. Factors which influence the composition of manures. 1. Influence of feed and age of animals. (a) Where feed is the same manure is richer in case of (1) Mature animals. (2) Those not producing milk or bearing young. 2. Charactef of feed. (a) The richer the feed in plant food elements, the more value the manure will have as a fertilizer. 3. Influence of absorbents. (a) The amount and composition of bedding and other absorbents will affect the value of manure. 4. Influence of care. (a) Four-fifth of the value of manure may be lost if allowed to leach. (bo) Horse manure may "fire-fang" and lose nitrogen (c) Manure should be kept compact and moist for best results. Stall manure lost 15% of nitrogen, yard man- ure 30 - 40% in same time. (d) Should be left in large rather than small piles, if necessary to pile. B. Horse Manure. 1. On account of less complete digestion in the animal this manure is loose in physical character and easily ferments and loses nitrogen. This heating character- istic is of value in making hotbeds and cold frames. 2. Composition. (a) Solid portion 55% N, «30% P2905, ~-40% KoO (bo) Liquid portion 1.35% ® 1.25% * (c) Mixed (liquid & solid) .7%% .25% * .55% (d) Pounds in o toh 14 § " ll sot" 61 3. Amount produced per animal. (a9) 1004 dry matter in feed will produce 210# manure with 77.5% water. (b) Allowing 6.5# of bedding per animal per day each horse would produce 6} - 7 1/3 tons of manure per year. Cow Manure. 1. The food of the cow is better digested than that of the horse. 2. Composition. (a) Liquid 1.32% N, Po0g, 1.00% KoO. (bo) Mixture ~51% " 035% = 51% * (c) Pounds per ton 10.2 * 7 " 10.2 " 3. Amount of manure produced. (a) 100# dry feed produces 384# manure. (bo) About 654 of mixture per day, or 12 tons per year. (c) About one-fourth of the nitrogen in feed is used by the cow, one-fourth goes in the solid excrement and one-half in the liquid excrement. Sheep Manure. 1. Contains less water than horse or cow manure but ferments easily. 2. Composition. (a) Mixture -95% N, 2.35% PoOs, 1.00 Kg0 (bo) Pounds per ton 19 "* 7 20 * 3. Amount produced. (a) 100# feed produces 18354 manure. : (o>) 1 animal under average conditions produces about 1500# per year. Ge E. Hog Manure. 1. Much of this manure is left in field. 2 Varies widely in composition. 5. Composition: (a) Mixture -834 N, .04%P0, .61% Ko0 (0) Pounds per ton 16.6 " .8 -.* 12.2 " 4. Amount produced. (a) 100# dry feed will produce 237# manure. (o) 1 pig mekes about 14 tons per year. F. Hen Manure. lL. Materially different from other manures because voided in one portion. 2. Composition. (a) Average - 1.9%N, 1.5% Pos, » 79% Ko0 (ob) Pounds per ton 39.4" 30.6 *" 14.6 3. Amount produced. (a) About 40# per fowl per year. 4. General characteristics. (a) Nitrogen of this manure is easily lost by leaching. (bd) Should be supplemented with 12 - 154 of acid phos- phate, 4 - 5# muriate of potash, 5 - 10# of gypsum per 100# manure. (c) A black, sendy loam soil makes a good absorbent. (d) May burn small plants when applied as a top dressing. G. Absorbents. 1. Principal kinds used. (a) Peat or muck. - This substance is undoubtedly a good absorbent for manure because of its great power toa CS take up water. It also contains about 2.54 N, ~88% P2005, .34% K20. Sprinkled dry in stalls and gutters best. (bo) Loamy soil good but quite heavy to handle. (c) Gypsum is frequently used. It changes ammonium carbonate to ammonium sulphate which stays in the pile. 100 - 1207 per ton a good treatment. (ad) Acid phosphate and raw rock phosphate make good absorbents and also reinforce the manure with phosphoric acid. H. Application of manures. 1. ae Well rotted manure gives best results. Fresh manure should be applied long before seeding - effects worse on sandy soils. Direct application better than storage; however, economy of hauling must be considered. Danger of loss on slopes depemds upon: (a) Absorbing power of soil - tight soils, steep slopes, frozen soil, ice sheet, and heavy rains all tend toward producing loss in applied manures. The general opinion is that manure should be plowed under an light soils but on heavy soils it should be spread on the plowed surface and disked or harrowed in. Great losses result when manure is spread on soil in warm windy weather. Just before a rain or a light fall of snow is a good ‘time to apply menure as the ammoniumearbonate may be carried into the soil better. 8. Manure should be spread evenly. 9. The practical benefits of manure come from its phy- sical effect upon soil texture as well as its plant food value. 10. Manure may be profitably supplemented by chemical fertilizers - phosphoric acid and potash. ll. Best place formanure in tne general rotation is on clover sod for long-season crops like corn, beans or potatoes. It may also be useful as a top dressing. ne 4 ‘ a ey SYSTEMS and PRINCIPLES of FERTILIZATION FROMM SOIL and CROP STANDPOINT. Ae Factors to be considered in applying fertilizers. 1. The character of the soil. - Whether sand, loam, or clay. 2. Moisture conditions. - Whether wet or dry. Thss refers to both soil and season. oS. Kind of subsoil. - Whether loose, medium, or tight - deep or close to surface. Conditions with respect to hardpan. 4. Previous soil treatment. - Manuring, legumes, cultivation, fertilization, produce sold or fed on land. 5. Object of growing the crop. - Whether for early or late produce, immature produce, or matured seed. 56. Kind and habits of crop. - Whether cereals, legumes, trees, etc., root systems, early or late developing. B. Systems of fertilization. lL. System of Ville. - This system is based on the specific influence of a certain element upon the crop. Nitrogen seems best for wheat, rye, oats, barley, grass, and suga@ beets. Phosphorus for turnips, rutabegas, corn, sorghum, and sugar cane. Potassium for peas, beans, clover, vetches, flax, and potatoes. z. The German system. - An abundant application of the mi ner- als because they are not lost much by leaching. The nitrogen is then added in small amounts, in soluble forms, when needed by the plants. This system is highly desired for market garden crops, o. The Chemical analysis System. - Heavy applications made to soils for money crop and no other applications during 'y CG the rotation. Note. - All these systems presuppose that the soil is in good mechanical condition, has the proper reaction, and well supplied with organic matter. C. Fertilization of cereals. 1. General characteristics of the cereals. - The roots branch just below the surface, and each shoot produces feeding roots which grow in every direction and absorb food from the lower layers of the soil as the plant grows Older. Their root system is wide and they are able to acquire food from the insoluble phosphates and potassium compounds of the soil, but they do not seem to be able to feed to any extent upon the insoluble N compounds. (Corn is an exception.) They develop early in the sum- mer before nitrates are fonmed in the soil and are es- pecially benefitted by applications of soluble N fertilizers. 2. Fertilization of cereals. (a) Gorn. - A crop of 50 bu. shelled corn with stalks will remove from the soil 80bs. N, 29# PoOe, 55# Ko. It is an exhaustive crop. A part of the Bods should be soluble and the rest ground bone or tankage. The KoO may be applied as KCl or Kainit, but KCl is pre- ferable if applied in the drill which is perfectly safe for the plant. If soil is light and sandy N should be added even thYough manure is used. The amount of N needed would be supplied in 100# high grade blood or 200# cotton-seed meal. (b>) Forage corn. - When grown after clover or on good soil 500% of a 2-6-8 fertilizer makes a good dressing. If s0il is poor more N should be used when there is no clover or manure, and organic N is preferable. P50 in superphosphates, and KoO as Kainit or KCl. Kainit should be well worked into the soil. (c) (d) (e) (f) (g) (nh) (i) a7 Silage corn. - The object of growth is to obtain a large yield of dry matter rich in nitrogenous substan- ces and poor in starch and woody fibre. More N should be used than for field corn. 3S0#N, 40# PoO., 60¢ Ko0 - (250# dried blood or 450# cotton- seed meal, 3007 acid phosphate, 120# muriate of potash.) Wheat. - For wheat following oats farm manure after plowing wetl disked or harrowed in and a fertilizer rich in available Po0s with a sufficient amount of available N to give a good fall growth. When the soil has been well fertilized for previous crops a dissolved animal bone superphosphate is a good fertilizer for wheat (200 - 300#). If more N is needed, as is fre- quently the case,when the winter has been severe or the soil is light, use NaNOz in the spring as a top dressing (75 - 150#). Wheat and rye for forage. - Larger amounts of N. should be used to give succulence and a larger growth of leaf and stem. When sown after fertilized corn, N and Po05 may be used, but if sown on poor soils the three ele- ments are necessary and some top-dressings should be made in the spring. The N should be in quickly avail- able forms. Oats. - This crop develops early in the season s0 quickly available forms of N are ddsirable, as is also Po505 which is used in large quantities by the oat crop. Nitrate of soda and superphosphates have proven of value to this crop. 5O# NaNOz, 150# acid phosphate. An application of K50 is not necessary #f applied to corn preceding oats, except on light sandy soils. Oats for forage. - Oats are adapted for forage because they make a good, early growth in moist, cool weather. 12# N, 20# PoOs, 10# KoO makes a good dressing (NaNOz, superphosphates, KCl). Shortly after germina- tion there is a period when growth is extremely slow (pouting period) supposed to be due to lack of plant food early in the season. Nitrates and superphosphates shorten and sometimes stop this period which is inm- portant in case of forage crops. Winter oats should be fertilized in the same manner as @heat. Millets. - These are surface feeders and are particul- arly benefited by liberal applications of all the ele- ments. Maximum crops can not be maintained without a good supply of plant food. N and P.O, should be large- ly in soluble forms. 150# NaNOz, 2602 acid phosphate 100# KCl has given good results. Buckwheat. - This crop is well adapted to mountain lahds and is extensively used in breaking new lands. Po0s (J) (x) D. Fertili 68 most required. Heavy N fertilization is not required because the growth is mostly in July and August. Light soils deficient in organic matter require N for thiscrop. On medium soils 10# N, 25# Ko0, good fertilization. Barley. = Characteristics and fertilization similar to wheat. This crop has a short period of growth and a limited root system and requires plant food in available forms. When used for feeding N should be liberally used but for malting less N and more K50 is desirable to give more starch. Salt is success- fully used snd is supposed to make the insoluble K,O0 compounds of the soil more saluble. N should be uded with care in order to prevent lodging. Rye. - Characteristics almost the same as wheat, and fertilization should be the same on similar soils. Excessive N should be avoided. zation of grasses. l. General characteristics. - Nearly all species of grasses are perenniel. They send their fibrous roots into the surface soil in the same manner as the cereals, but they form a set of buds which become active in the late summer and develop new roots and shoots. They resemble the cereals in their power to gather food and are even more benefited by applications of soluble N fertilizers. Leaf and stem growth are desired and not matured grain, hence a good N supply should be maintained. 2. Fertilization. (a) Timothy. - Especially benefited by N fertilizers when the minerals are well supplied. It is best to apply minerals in the spring as a top-dressing. An applice- tion of 150# NaNOz, 100# acid phosphate and 50# KCl per acre is now used by many successful hay growers. The application should be made as soon as the crop has well started in the spring. Lawn grasses. - Well rotted manure spread in winter or early spring and raked over as soon as growing weather begins is one of the best treatments for lawns, but manure is troublesome because it introduces weed seeds. 5 parts ground bone and 1 pt. KCl make an excellent dressing before seeding, 5# to the sq. rd. CG as a top-dressing twice or thrice during the season; the first just after the plants have come up and the others just before a rain. Ground bone and KCl may also be used as a top-dressing. Too much KCl encour- ages the growth of the clovers. E. Legumes. 1. General Characteristics. - The clovers are not perennial (except white or Dutch clover) and with this exception they possess a tap root which grows downward and sends out fibrous roots at different levels. They are capable of readily acquiring their mineral food and get N from the air. The tendency of their growth is to inrich the soil with N. 2. Fertilization. (a) () (c) (d) Clover. - When clover follows wheat that has been fertilized with N or manure only P Os and Ko0 need to be applied. l12# Po205, 25# Ke0 (1064 acid phosphate, 50# KCl) is a minimum dressing and may be applied as soon as the wheat has been harvested. Cloversfor forage. - They get plant food which is in accessible to the cereals, and are less exhaustive. They furnish early food. On soils of medium fertility the need of N is not marked. On light soils N is servicBable, before the plant can get N from the air. A good supply of minerals is desirable, and less avail- able forms of Po.0s5 maybe used. Alfalfa. - Requires an abundance of mineral food. In- soluble forms may be used for preparatory dressings but soluble forms are bdst for top-dressings which may be made annually. 125# NaNO.z, 600# acid phosphate, 400# KCl a good preparatory fertilizer. Top-dress- ings should provide 30f Po0s, and 100# Ko0 . The fertilizer may be used on the preseding grain or cultivated crop. Cow pea and soy bean. - Obtain their food during a short period and hence require more plant food than the clovers. 200# acid phosphate and 100# KCl a good dressing on medium soils for clovers, but should be increased by about one-half for summer crops. 70 (e) Peanut. - A legume, not especially benefited by N fertilizers. 300# achd phosphate and 100# Kainit good. Lime is useful, 20 bu. per A. once in four years. (f) Beans. - Ko0 best on clay soils. 200-4008 of a 2-8-10 fertilizer good. WN. should be preferably in organic forms, and minerals well supplied. Superphosphates and KCl good forms. (g) Peas. - Similar to beans. (See market garden crops.) F. Meadows. 1. Characteristics. - See characteristics of grasses and legumes. 2. Fertilization. - A liberal application of mineral elements is recommended because they encourage growth of clovers and make a richer herbage than grasses. Heavy N fertili- zation is expensive and encourages grasses rather than clovers. Mixtures of acid phosphate, ground bone and KCl make good dressings, when used in equal proportions at the rate of 300-500# annually. The ground bone is recommended because it furnishes a continuous supply of N and PoQ5. Applications should be made in spring and late summer to encourage clovers. When organic matter is added to the soil in large quantities it is advisable to make an application of lime. G. Forage crops. - Cereals and Legumes. 1. Characteristics - See characteristics of cereals and legumes. 2. Fertilization. (a) Oats and peas. - More of thdminerals should be applied to encourage growth of the pea crop. It is also desirable to encourage the growth of the oats by the use of N. 75% NaNOz, 1757 acid phosphate, 25# KCl good. 71 (bd) Barley and peas. - A good combination when late fall forage is meeded and is adapted to fall conditions. Fertilization should be liberal. Same as for oats and peas above. H. Root crops. 1. Characteristics. - The crops can not make ready use of ae the insoluble mineral compounds of the soil. They must be liberally supplied with soluble mineral foods. Phos- phates are useful to turnips while the slow growing ( beets and carrots require N in quickly available forms. Root crops are exhaustive of plant food elements, more so in proportion to dry matter contained in them than legumes. It requires twice as much root crop to supply the same amount of food as in legumes. 20 tons of roots contain 60# N, 354 Po0s, and 150# KoO. Fertilization. (a) Fodder beets and carrots. - Require liberal amounts of (b) (c) N and PoOsin available forms to meet the large and early demand of the plant for them. K,O is essential On soils of a light character; these plants are better able to obtain this compound on loam and clay soils. A liberal use of barnyard manure is good. 40#N, SO0# PoOs, and 100# Ko0 makes a good application. N should Re applied in fractional dressings, and the crop cultivated soon after. Turnips, Sweeds, and rape for Fodder. - These plants are able to get Po05from combinations not readily reached by other plants. 20# N, 40# Po0c, 40# Ko0 a good dressing. Success with these crops depends largely upon having a good supply of plant food on hand so as to give a rapid continuous growth. Sugar beets. - This crop draws heavily on the soil for N and K,O. On rich, loamy soils K,0 is not necessary but is Sn light, sandy ones. Growth must be forced early in the season. Too long or too rapid growth has a tendency to decrease the sugar content.