Influence of fertilizers, minor elements, and soil ph on the growth and protein content of tropical kudzu

Abstract

The effect of fertilizers and lime on the yield and protein production of tropical kudzu, as observed in the experiments here reported, is as follows: 1. In a greenhouse experiment, kudzu yields increased with increased pH on limed soils, with the highest yield at pH 7.5. 2. Nitrogen and phosphorus produced significant increases in the yield of green forage in a fertilizer experiment on a Río Piedras clay. No such increases were obtained with potash fertilizers. 3. Liming increased yields for the first cutting of kudzu only in a fertilizer- lime experiment on a heavy plastic Fajardo clay. Nitrogen was also of significant value in increasing forage yields and protein for the first cutting only. The second and third cuttings had no yield or protein increases that could be attributed to any fertilizer or lime treatment. 4. At Corozal, on a friable, acid Lares clay, kudzu did not respond to nitrogen, phosphorus, and potassium fertilizers. The response to liming was in protein content and then only in the second and third cuttings. 5. The use of nitrogen and lime is of value in establishing good productive stands of kudzu on very acid soils (pH below 5) of low fertility. 6. The effects of the use of borax and of magnesium oxide as minor-element fertilizers were negligible from the standpoint of yield and protein production.