were originally covered with forest growth. The growing of grasses and pasturing have been mentioned as means of increasing the organic matter. The plowing under of clover and green manuring crops, and the use of manure are especially recommended as means of increasing the nitrogen supply. Phosphates for Clays.-Heavy soils usually contain large amounts of potassium. When well drained and sufficiently supplied with organic matter potash fertilizers are seldom required on these soils. The phosphorus needs of clays are quite general, so that the use of phosphate fertilizers is usually highly profitable. For immediate results, acid phosphate may be used at the rate of 200 to 300 pounds per acre for grain and 400 to 500 pounds per acre for corn. Rock phosphate, when mixed with manure or plowed under with clover or green rye, has given excellent results (Fig. 148, p. 198. See Rock Phosphate, index). Basic slag is especially good to use on clays, but in most sections of the United States it is not obtainable. Many clays are red in color, due largely to the presence of iron compounds. Frequently this iron makes the phosphorus unavailable. On some of these soils acid phosphate is rendered entirely ineffective within a year or two after it is applied. The application of agricultural lime is an effective remedy. Erosion. Because of their location or topography, many clay soils are particularly subject to washing, or erosion. The cultivation of these lands greatly increases their tendency to wash. In most cases it is best to keep such lands in grass. When some of the more gentle slopes are brought under cultivation, plowing should be done at right angles to the slopes. Often it is advisable to terrace a slope or leave open dead furrows in such a way as to enable the surface water to run off by following more gentle inclines. Deep fall plowing and subsoiling also aid in preventing erosion (see index). A further discussion of erosion may be found in Chapter XXIII. Other Points on Clay Management.-Clearing clay lands of underbrush, small stumps and dead timber is not, as a rule, a very expensive process. Removing stumps by combining the use of dynamite and the stump puller seems to be the most economical method. It is much easier to blast out stumps when the ground is moist or wet and when they are given a few years to rot after the timber is cut. ROTATIONS AND TYPES OF FARMING 325 When cleared of timber and brush it is advisable to get clover started as soon as possible, not merely to provide pasturage and hay, but to help in controlling the weeds and to improve the soil. A spring-tooth harrow or a disk is helpful in getting the clover seeded. Plowing. It requires a good plow to turn heavy clays well. In some sections the disk plow is the best to use. Fall plowing is usually advisable. Subsoiling to deepen the seed bed and to create a more open subsoil is sometimes practiced. Dynamite is also used at times to open the subsoil so as to facilitate the entrance of air, water and roots. It is best to do either subsoiling or dynamiting when the ground is sufficiently dry to prevent puddling (Chapter X). Crops for Heavy Clays.-Because of their fine texture, clays are especially well adapted to crops having fine and fibrous roots, such as red-top, timothy, etc. Crop adaptation to heavy clays may be summarized as follows: Rotations and Types of Farming.-Much depends upon a good system of cropping to increase the productive power of clays. The following are good rotations for dairy farms: A-1. Corn (manured). 2. Grain (seeded to clover and timothy). 3. Clover. 4. Pasture or mixed hay. B-1. Wheat (seeded to sweet clover to plow under). 2. Corn (manured). 3. Oats (seeded to clover). 4. Clover. When the oats are seeded to a mixture of grasses this may be made a five-year rotation with pasture the fifth year. C-1. Wheat (seeded to clover); (fertilized). 2. Clover. 3. Corn (properly fertilized). 4. Peas (peas for sale as seed). D—1. Small grain (seeded to mixed grasses). 2. Clover. 3. Mixed hay or pasture. 4. Peas (cash crop). 5. A cultivated crop. For grain-farming, the following rotation is well adapted: E-1. Spring wheat (seeded to clover and timothy). 2. Clover (cut for seed). 3. Mixed hay. 4. Peas (for sale as seed). IMPROVEMENT OF DEPLETED SILT LOAMS Depleted silt loams are common particularly in the Eastern and Central states. They are the result of too severe cropping, with little or no attention given to the maintenance of their fertility. As a rule, these soils are low in organic matter and nitrogen, they are commonly acid, and are in need of available phosphorus. Liming is usually the first step to be considered in their improvement, the object being, mainly, to improve the conditions for growing clover and other legumes. Plowing under legumes is recognized as the best method to increase the organic matter and nitrogen. Manure, when available, generally gives good returns when applied to the clover fields. Liberal applications of soluble phosphates should be made to the grain and cultivated crops. Acid phosphate is generally considered the best phosphate fertilizer to use in beginning soil improvement. Later on, when improvements shall have been well advanced, rock phosphate may take the place of the acid phosphate. A short rotation including clover is also an important factor to be considered in the regeneration of these soils (Chapters XII, XIII, XV). Field Studies.-1. Select a run-down farm and make careful observations as regards general appearance, weeds, character of crop growth, and soil conditions. Suggest remedies. Home Projects. Select three acres of depleted silt loam, or an acre, and divide into three equal portions. Fertilize properly. Establish a three-year rotation, corn, grain and clover. Plow under the first crop of clover, and always the second growth. Students may continue the rotation for at least six years, and note soil improvement. Other rotations suited may be substituted, or may be conducted in addition to the one suggested. QUESTIONS 1. Compare clay soils with sands in their workability and texture. What is "gumbo"? 2. Name the special problems in the management of clays. State briefly their solutions. 3. Discuss drainage in relation to clay management: (a) benefits; (b) methods; (c) depth of tile, fall, "blinding," distance apart to lay lines of tile. 4. Discuss tilth in relation to clay management. 5. How may the organic matter and nitrogen in clay soils be increased? 6. What special fertilizer do clays commonly require? What is the relation of lime to fertilizer needs on some clays? 7. What is erosion and how does it affect clay lands? Name some means of prevention. 8. Describe a good method for clearing stumpy clay lands. 9. Name crops that are particularly adapted to clay soils. Crops that can be grown successfully on good management. What crops are not adapted to clays? Why? 10. Name two good rotations for dairy-farming on clay land. A rotation for grain-farming. 11. Discuss the improvement of depleted silt loams. 12. What crops have you observed growing on very heavy clay soils? 13. See outline summary of this chapter in table of contents. CHAPTER XX FARM MANAGEMENT AND CROP ROTATION Soil Problems Are Prominent in Farm Management.-The most successful system of farming is that which gives the largest profit, increases soil fertility, and brings to the farmer and his family the largest amount of happiness. Successful farm management presents many problems, the most important of which concerns the growing of suitable crops, the adaptation of crops to soil, the care of the soil and crops, the disposition made of the crops, and the distribution and use of labor. The problems involving soil relations are usually of fundamental importance and thus are given special attention. Indeed, it is self-evident that productive soil is the basis of profitable farming. The old style of farming has been largely the one-crop systema system which has generally led to soil depletion. Modern agriculture and scientific farming demands the growing of several crops, chiefly because of its beneficial effects on soil fertility. Thus diversified farming has become of national importance. Advantages in Growing Different Crops.-There are several advantages to be gained in growing different kinds of crops, important of which are: (a) It economizes in the use of labor; (b) a more dependable income is assured; (c) it permits of crop rotation. Different kinds of crops necessarily require different planting and harvest times. The labor required to care for the crops is extended more uniformly over a longer period than when just one crop is grown. Moreover, a diversity of crops encourages the keeping of more livestock, the care of which utilizes labor, especially during winter months. The growing of one crop means just one source of farm income, and that is rather uncertain at times. The growing of several crops provides a more dependable income. When the weather is bad or prices low for one crop, the conditions or prices are usually favorable for some other crop. To establish more than one source of income is good business. It is self-evident that rotation is made possible only when two or more different crops are grown. The importance of rotation in farm management and its application are fully discussed in the following paragraphs. Rotation an Essential Factor in Farm Management.-Crop rotation is a most essential factor in successful farm management, because it aids materially in increasing and maintaining soil fertility, in systematizing farm operations, and in solving certain other soil and crop problems. The relation of rotation to soil fertility has been fully discussed in Chapter XV. Rotation implies system. The adoption of definite cropping plans is the beginning of systematic farming, affecting not only the growing of crops, but field management and the use of labor as well. Problems concerning the adaptation of crops to certain fields, the effect of one crop on another, soil renovation, the management of special soils, etc., are best solved through crop rotation. Rotation in Practice.-In establishing a fixed rotation, it is necessary to divide the farm into uniform fields or units on which are grown the different crops. Each year the crop on each field or unit is changed according to the adopted plan. For example: A certain farm consists of 100 acres, sixty acres of which are under cultivation and are divided into three twenty-acre fields; the remaining forty acres includes permanent pasture, orchard, yard, garden, etc. The farmer wishes to grow annually twenty acres, each, of corn, oats and clover; thus a three-year rotation is planned as follows: This is the simplest conception of a practical rotation. Comparatively few farms, however, lend themselves to such a simple arrangement because of certain conditions or factors which present themselves. Usually two or more different rotations are necessary on each farm. Factors Which Determine Kinds of Rotations.-The rotations best suited to any particular farm are determined by― (a) The feeding requirements of the stock kept. |