Proceedings of Seventeenth Noemal Institute 1 C, 



needed for its growth ; and by incorporating the clover in the soil 

 (green mannring), potassium which the chemist finds insoluble 

 by present methods, and regards as of no fertilizing value, may 

 be made readily available. 



The decay of other organic matter, like manure, also releases 

 the " locked-up " potassium in the soil. 



Sulphur and soil fertility. (Ky. 188.) Sulphur or gypsum 

 in addition to a complete fertilizer gave a decided increase in 

 growth of Yellow Pryor tobacco. Different sulphur compounds 

 applied to the soil resulted in increased growth of soy beans, the 

 best effect being produced by sulphur itself. Turnips were 

 materially benefited by the use of sulphur fertilizers. Clover, 

 however, was net benefited by sulphur compounds except potas- 

 sium sul|)hate, and the result there may have been due to the 

 potassium. On cabbage, sulphates of iron, nickel, copper, cobalt, 

 chromium, manganese, lithium, etc., were compared with car- 

 bonates of the same materials. Only two of the sulphates were 

 beneficial, a few had no effect and several w^ere harmful. Mus- 

 tard following the cabbages showed gains over the check plats 

 from several of the sulphates, and all gave better results than the 

 corresponding carbonates. Padishes on the same plats gave ir- 

 regTilar results, but there is no doubt that the sulphur fertilization 

 was beneficial in some cases. 



With alfalfa in sand cultures, better growth was secured from 

 the use of nine out of fifteen sulphates than from carbonates of 

 the same elements. 



Radium, as a fertilizer. (111. 177.) Eadium applied at a 

 cost of $1, $10 or $100 per acre produced no effect upon crop 

 yields either the first or second season. 



Utilization of septic tank sludge. (Cal. 251.) This is a plea 

 for the utilization of human excreta and other household wastes 

 as collected in some of the sewage disposal systems, and is well 

 worth studv, although no verv definite methods are outlined nor 

 costs computed for handling such materials. 



How not to treat Illinois soils. (111. Circ. 181.) This lecture 

 before the Illinois State Farmers' Institute is a plea for use of 

 single or united fertilizer elements, generally phosphoric acid, 

 occasionally potash, with liming, for soil improvement, rather than 



