The probable need of lime has been discussed in other chapters. Clovers and the grasses want an alkaline soil, and there is waste of money and time in seeding acid land. The lime and the manure must not be mixed together in the air, but both can be used when fitting land for seeding, and both should be used if the need exists. One should be applied early and be well disked into the soil, and then the other application may be made and covered with the harrow. The soil is an absorbent, and the contact of manure and lime within the soil only leads to immediate availability, which is desirable in giving the grass a start.
CHAPTER VIII
GRASS SODS—(Continued)
Seeding in Late Summer.—The natural time of beginning life, in the case of timothy, blue-grass, red-top, red clover, and alfalfa is in the summer or autumn. The best conditions of growth are given where no stronger plants take the plant-food and moisture. Wherever there is any difficulty in getting heavy grass and clover sods after the lime deficiency has been met, and wherever a hay crop has more value than a small-grain crop, the method of seeding alone in August should be employed. In warmer latitudes the date may be a little later, but in the northern states it should be in the first half of August for best results. Seeding alone offers opportunity to make conditions right for the seeds which are to be used, and in view of the importance of heavy sods to our agriculture, this reason alone is sufficient. In some regions the ability to substitute a good hay crop for a cereal that brings small net income is an item of value, adding to the proportion of feeding-stuff produced in the rotation and to the resulting supply of manure. The practice of making seedings to grass and clover alone is growing, and it is based on sound reasoning.
Crops that may Precede.—Farms that are under common crop-rotations may adopt the practice of August seeding. The winter wheat comes off in time for preparation, and this is true of an early variety of oats, and of rye and barley. Early crops of vegetables get out of the way nicely. There is a vast total area of thin soil that may be brought up to a productive stage rapidly by the growth of a green-manuring crop to precede the grass and clover. Rye may be sown in the fall and plowed down in May, and cowpeas planted to be disked into the soil. Oats and Canada peas add organic matter with nitrogen when plowed down. The summer fallow, which deservedly has fallen into general disuse, may well be employed when a soil is in an inert state, provided grass and clover be permitted to appropriate the plant-food made soluble by the fallowing. The catch crops add organic matter while cleansing the land of weeds; the fallowing releases plant-food and is peculiarly efficient in killing out weeds.
Care must be exercised about preserving moisture in the ground, and therefore a green crop should not be plowed under immediately before seeding time. When a soil is thin, there may be no better preparatory crop than the cowpea, which will not make too rank a growth in the north to prevent its handling with a weighted disk harrow. By this means the soil below is left firm, and the rich vines are mixed with the surface soil, where most needed. It is always a mistake to bury fertility in the bottom of the furrow when a soil is thin and small seeds are to be sown. The infertile ground lying next the subsoil is not what is needed at the surface when preparing for a sod.
It is a good practice to use the early summer in making conditions better for an August seeding, if the land has fallen below a profitable state of productiveness. A growth may be plowed down in time for firming the seed-bed, or it may be cut into the surface soil with a harrow, or the time may be used in freeing inert plant-food and destroying weed seed. On better soils, and in warm latitudes, a crop for hay may be removed, especially in the case of the cowpea in the south, and the stubble prepared for seeding by use of the cutaway or disk harrow.
Preparation.—A seed-bed for small seeds planted in mid-summer must be able to retain moisture. Nothing robs a soil of water more surely than a breaking-plow. Its use is a necessity in farming, but this effect of plowing must be borne in mind when a seeding is planned for the driest period of the year. It goes without saying that sods should not be formed on land that is too solid for admission of air. A thorough plowing is needed by most soils prior to making a sod that will prevent further stirring of the ground for a long period of time. It is best when this plowing can be given in the preceding spring. This enables the ground to become firm enough to hold moisture. If there is time for a tilled crop, the cultivation is helpful. When the land must be broken in the summer, the plowing should be done several weeks before the seeding to grass must be made. The roller should follow the plow closely to destroy the spaces that lie open to the hot air, permitting the land to dry out. All deep harrowings should be given soon after the plowing, stirring and mixing the ground, and then leaving it to settle so that moisture can be held. It is bad practice to continue deep harrowing until the seeding time of any small grain or grass planted in a dry part of the year. Firmness is wanted in the soil.
The Weed Seed.—The seeds of tilled crops are planted in ground containing much weed seed, and no harm may result. The cultivation needed to keep the soil loose, or to prevent evaporation, destroys the weeds. Grass, clover, alfalfa, and like seeds are put into the ground to occupy it to the exclusion of other plants for several years, as a rule, and no tillage can be given. The rule is to sow such seeds after tilled crops have been grown, and some weed seed has been destroyed, but there is evidence on every hand that the weed seed remains in abundance. Summer preparation for grass gives opportunity to destroy a great part of the seeds in the surface of the ground, and it is only when they are near the surface that the seeds of most weeds will germinate. Deep harrowings, continued up to time of planting, not only rob land of water, but they bring to the surface new lots of seed that had been safely buried, and become a part of the actual seeding when the grass, clover, or alfalfa is sown. The obviously right method of preparing for planting is to use only a surface harrow for a few weeks previous to seeding time, stirring the ground after every rain to the depth of three inches, or near that, and destroying the plants soon after germination of the seed. The process which is right for holding moisture is right for cleansing the ground.