The value of cover crops in continuous corn culture
1938
Odland, T.E. | Knoblauch, H.C.
Corn was grown continuously over a period of 40 years with a comparison of both legume and nonlegume cover crops and no cover crop. Variations in fertilization and disposition of the corn stover were also included. The legume cover crops were the most effective in maintaining the yields of corn in this test. Winter rye seeded at the last cultivation of the corn in the fall increased the average annual yield by 6 bushels per acre over the adjoining no-cover-crop section for the 34 year period Of 19OO-1933. The yields of stover were increased by both the legume and rye cover crops. The increase in yield of stover was not as large in proportion, however, as the increase in yield of grain. Increasing the nitrogen content in the fertilizer by 50% on one-half of the rye cover crop section resulted in an average annual increase of 12 bushels per acre over the half with the regular amount of nitrogen. The total amount of nitrogen in the soil showed a gradual decrease on all sections. Both the legume and rye cover crops lessened the rate of decrease in total nitrogen. The cover crops used increased the water-holding capacity of the soil. This experiment has definitely shown that under conditions such as prevail where this test was conducted the practice of using cover crops for conserving soil productivity is a highly desirable practice and should be encouraged. Where a legume cover crop can be used successfully this is to be preferred. Rye, although a nonlegume, will also show decided benefits to the soil and crop grown.
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