Nitrogen in relation to crop production in the Middle West
1922
Conner, S.D.
Except on those soils which still have a large portion of unexhausted nitrogen left, the nitrogen problem is the most important soil fertility problem before the corn belt farmer. Average Indiana soils have lost approximately twenty pounds of nitrogen per acre per year for the last half century and this loss is continuing. Some soils have lost over 40 pounds per acre per year and the time has arrived when the lack of nitrogen is seriously reducing yields. Legumes and manure are needed in a much larger degree. Less than one acre in ten is in legumes in the Middle West. The proportion of legumes to other crops should be increased two or three times for best results. On lands which have been exhaustively cropped some nitrogen in the fertilizer will be profitable, at least until more legumes are grown and crop residues and manure conserved and returned to the land. Much of the profit in the use of lime, phosphate and potash is in the beneficial effect on legumes, thus indirectly these materials act as nitrogenous fertilizers.
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