All in all, oats need little fertilization. The Ohio Experiment Station (Circular 54) found that while the addition of a complete fertilizer to oats increased the yield, the increase failed to pay for the fertilizer in one case and barely paid expenses in another. It was found, however, that when phosphorus alone was used, a marked increase resulted and at a profit. The fertilizer applied will have to depend on the soil and is largely a matter of judgment.
Depth of seeding.—The proper depth to sow the seed and the best method of sowing will depend much on the soil. Better results have been obtained by shallow sowing. The Illinois Experiment Station in a six years' trial has found one inch to be the best depth at which to sow oats. This was corrobo rated by the Ohio Experiment Station, where seed ing at a depth of one inch gave a yield of 3.56 bushels more per acre than when the grain was sown two inches deep, and 7.73 bushels more than when sown three inches deep. All things taken into consideration, drilling is the best way of seed ing when the seed-bed is properly prepared, because the depth of seeding can be made more precise and uniform. No especial advantage has been found in ordinary drilling over broadcasting. Large areas, however, are now drilled on old corn land by using disk drills. Broadcasting in this manner necessi tates sowing slightly more seed per acre.
It is well, in all cases, to follow the seeder with a harrow to aid in covering the seed in the case of broadcasting, and to level the soil in any case, as well as to aid in preserving the best soil mulch. A common harrow or drag with teeth set at an angle of 45° makes a good tool for the purpose.
Rate of seeding.—The rate per acre at which the seed should be sown will depend largely on the location and the preparation of the seed-bed. Oats stool abundantly and indications are that a major ity of farmers sow too much seed per acre. Experi ments at ten experiment stations have led to the recommendation of eight to sixteen pecks to the acre, with an average of ten pecks. When the seed is clean and well graded and the viability is high, ten pecks to the acre should be ample. In the corn-belt, where oats are sown on corn ground with only a surface disking, it is customary to sow four bushels of seed per acre ; and in Scotland as high as seven and one-half bushels per acre are sown.
Place in the rotation.—Few crops fit into rota tions in all parts of the country as well as do oats. In the West, where wheat is so largely grown, we find the following rotation : Corn, oats and wheat each one year, and clover and timothy two years. In the central states we have corn and oats, each one year, and clover and timothy two years. This rotation predominates also in the corn-belt, but is there liable to variation, such as corn two years, oats one year, clover one year or clover and timo thy two years. On many farms in the corn-belt, a three-year rotation of corn, oats and clover is practiced, while some of the more shiftless farmers maintain a two-year rotation of corn and oats. This latter custom in time is certain to deplete the fertility of the land and should be condemned.
Southern farmers use oats in the rotation with corn, cowpeas and cotton. These are combined in various ways, but the most common method is to sow cowpeas with corn the first year, putting the cowpeas between the rows of corn and harvesting them for the grain. Then fall-sown oats are re moved in time the next summer to put on a crop of cowpeas which is cut for hay ; this crop is followed by cotton one or two years, depending on soil conditions.
Subsequent care.--After the grain is up, nothing further need be done until harvest time in an ordi nary season. When, however, moisture is very abundant and the soil fairly fertile it may be advisable to clip back the oats slightly to prevent lodging. This delays the ripening somewhat, but may obviate a heavy loss from lodging. The Iowa Experiment Station found (Bulletin No. 45) that cutting back to the third leaf from the ground when most of the plants had five leaves not only increased the yield eleven and one-half bushels per acre over that which was not clipped, but the grain remained erect after that which was not clipped was badly lodged. The cutting back delayed ripening four days, so that little risk was run in clipping Harvesting and threshing.
The time to harvest oats is when the grain has just passed from the "milk" into what is called the hard "dough" stage, or a very little later.