186 FIELD CROPS 



except on soils which are decidedly lacking in nitrogen. On 

 such soils, plowing under a leguminous crop for green manure 

 before sowing the oats is frequently of much benefit. This 

 is most necessary and can be done to best advantage in the 

 South, where oats are sown in the fall. On soils which are 

 lacking in potassium, the use of fertilizers containing that 

 mineral usually greatly increases the yield, and at the same 

 time tends toward the production of stiffer straw. In 

 general, where the use of commercial fertilizers is necessary, 

 the largest yields are obtained from the application of small 

 quantities of a mixture of all three of the important fertiliz- 

 ing elements, nitrogen, potassium, and phosphorus. 



229. Preparing the Land. As early seeding is desirable 

 in order to have the crop mature before hot weather, the 

 preparation of the seed bed should begin just as soon as 

 the land is in condition to work in the spring. A mellow, 

 rather loose surface soil with a firm subsoil is best for oats. 

 On fields where a cultivated crop was grown the previous 

 season, this is most quickly and easily obtained by the use 

 of the disk and the smoothing harrows. If the soil is natu- 

 rally rather loose or if the field had been plowed for the pre- 

 ceding crop, such as corn or potato land, just as good yields 

 are often obtained by disking without plowing as from any 

 other method of preparation. Generally, where it is possible 

 to do the work, fall plowing followed by spring disking and 

 harrowing will produce the largest yields most economically, 

 because soils so prepared are usually in the best shape to 

 store up moisture for the use of the crop. Spring plowing 

 frequently delays seeding, and unless the soil is thoroughly 

 packed to firm the lower layers, it is likely to be too loose for 

 the best results. 



Where oats follow some other small grain, the land is 

 quite generally plowed; but in the corn belt, where oats are 



