Effects of liming on response to minor elements of crimson clover, soybeans, and alyce clover

A field study was made of the effects of liming on the response to minor elements by crimson clover, soybeans, and Alyce clover. The experiment was conducted for seven consecutive years in small field plots on a Norfolk loamy sand located at Auburn, Ala. The results of the study indicate: 1. The variation in the requirements of the three legumes for additional minor elements is much larger than the effect that applications of lime have upon the deficiency of boron or of boron, copper, zinc, and manganese of this soil. 2. Norfolk loamy sand at Auburn is highly deficient in boron for crimson clover seed production, but the response in vegetative growth was small. The 4-year average yields (1942-1945) when borax was applied for the various liming rates was 90 pounds of seed per acre for the no-borax plots and 850 pounds of seed per acre where borax was applied. Addition of copper, zinc, and manganese gave only slight increases in seed yields, which ranged up to as much as 100 pounds per acre in 1945. 3. Dolomitic lime was superior to calcitic lime for crimson clover seed production where B, Cu, Zn, and Mn sulfates were applied. A need for additional magnesium where B, Cu, Zn, and Mn were used was also evidenced by decreases in yields of soybean and Alyce clover hays obtained from the calcitic lime. 4. Soybeans and Alyce clover require very little or no additional B, Cu, Zn, and Mn on this soil. 5. Alyce clover failed without lime on this soil regardless of the PK or minor element treatments. The optimum rate of lime for this crop was 3,000 pounds per acre where no minor elements were added and 8,000 pounds per acre where B, Cu, Zn, and Mn were applied. 6. Where borax was applied to the soil, the response of soybeans to lime increased with each increase in the amount of lime applied. This resulted, in part, from decreases in yield of the soybeans on the low-lime plots as compared to the no-boron plots. 7. Applications of either calcitic or dolomitic lime reduced the water-soluble boron content of soils regardless of the borax applied.