Nutrient balance in corn growing in southern states as revealed by purdue plant tissue tests
1944
Drake, M.
A study of the nutrient status in corn plants grown on soil fertility plots of the Alabama, Georgia, and Mississippi agricultural experiment stations was made with the Purdue plant tissue test technic. This was an efort to determine whether a deficiency in nitrogen, or potash or a lack of nutrient balances, or some other factors might be the principal causes for the numerous low corn yields in the South. In general, a lack of nitrogen was found to be the major factor limiting the yields of corn as shown by the plant tissue tests and by harvested results. Unless winter legumes were well fertilized with phosphorus and potassium, nitrogen was available in such small quantities for the corn that followed the legume that the plants were deficient in nitrates by tasseling time. Corn plants growing on plots where large crops of vetch had been plowed under consistently tested high in nitrates to the roasting ear stage. The plant tests showed that the practice of growing corn without until about 40 days after planting generally resulted in nitrogen starvation during the early growth period. In cases where cotton or some other well-fertilized crop did not precede the corn crop, as on the Georgia river terrace soil, the corn plants tested very low in phosphates. In general, the plant tissue that the amounts of phosphorus and potassium were adequate in the plants to balance the limited supply of nitrogen. omparing the amount of nitrogen which needs to be added as to produce 1 bushel of corn in the southern states with that needed in Indiana, it was found that in both regions approximately pounds (+/- 0.5) of nitrogen are required to make a bushel of corn.
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