Effect of Fertilizers and Lime on Emergence, Nitrogen Content, and Ratio of Roots to Tops in Hairy Vetch 1

N conducting work on the use and adaptation of I legumes for soil improvement during the last 10 years, the Department of Agronomy, Texas Agricultural Experiment Station, has found it desirable to determine the amount and nitrogen content of the vegetable matter plowed under. Previous investigations showed that the application of phosphate and potash greatly increased the yield of hairy vetch but had no significant effect on the percentages of nitrogen and phosphorus in the top growth (10).3 A large amount of work has been done to determine the proportion of roots and tops, and consequently the proportion of nitrogen in the roots and tops, of different legumes in various parts of the world. It has been shown that the distribution of nitrogen in different parts of the plant varies widely with the species, stage of growth, and the kind of soil on which the legume is grown. The distribution of nitrogen in different parts of the plant is important, especially in the use and management of legumes for soil improvement. For this reason the problem has been studied extensively by a number of workers. Brown and Stallings ( 5 ) conducted some of the most comprehensive work on the distribution of dry matter and nitrogen in legumes, using alfalfa and sweetclover. Pieters (9) gave an excellent review of the work done along this line up to 1927. He pointed out in general that biennial and perennial legumes, such as alfalfa and the clovers, have a larger proportion of their total dry matter and nitrogen in the roots than do the annual legumes, as vetches, peas, and soybeans. Fred, Baldwin, and McCoy (6) also gave a comprehensive review of work done on the distribution of nitrogen in tops and roots of legumes. Andrews (2) found that basic slag applied at the rate of 400 pounds per acre in contact with or below vetch seed was superior to side placement. Andrews (1) also reported that the roots of vetch contained 35% of the nitrogen in the whole plant. Rogers and Sturkie (12) in Alabama studied the effects of different methods of applying fertilizers on the nodulation, growth, and nitrogen content of hairy vetch. A combination of basic slag and muriate of potash was the best fertilizer used and there was little difference in yield of vetch whether the fertilizer was in contact with or separated from the seed. Superphosphate alone, however, produced considerably smaller yields of vetch than a mixture of superphosphate and