324 EXPEEIMENT STATION EECOED. [Vol. 36 



various commercial fertilizers. On auotlier field all combinations of nitrogen, 

 phosphoric acid, and potash applied at the rate of 50 lbs. of each element per 

 acre were ineffective. On two other fields fertilizers measurably increased 

 the yield. Where the land responded to fertilizers nitrogen was the only es- 

 sential element. A single test with plant cane showed that, calling the effective- 

 ness of ammonium sulphate 100, that of sodium nitrate was 100, that of tank- 

 age 111, and that of cyanamid 134. 



The residual effects of fertilizers, F, E. Beae, R. M. Salter et ai. {West 

 Virginia Sta. Bui. 160' (1916), pp. 3-26, figs. 2).— Analyses of samples of the 

 soil of fertilizer plats which have been under experiment for 15 years at the 

 station (E. S. R., 35, p. 22) are reported to show the effects on the soil of 

 different fertilizer treatments and of the crops produced. 



It was found that there was a gain in nitrogen averaging 20 lbs. per acre 

 per year on the plat receiving acid phosphate. On the plat on which acid phos- 

 phate and sulphate of potash were applied the gain in nitrogen amounted to 

 78 lbs. per acre per year. The phosphorus applied to the soil in excess of the 

 needs of the crops was not lost in the drainage water, but was fixed in the sur- 

 face Of in. of soil. Organic matter was maintained and increased by the use 

 of fertilizers without plowing under green manuring crops or crop residues 

 other than the stubble left behind after the crops were harvested. The use of 

 quicklime in excess of the needs of the soil caused a loss of nitrogen, phos- 

 phorus, and organic matter from the surface soil considerably larger than the 

 increased yields produced would justify. The use of manure or fertilizers 

 (with the exception of sulphate of potash) had a tendency to decrease the 

 acidity of the soil. 



[Experiments in Java with green manures], W. M. van Helten (Dept. 

 Landb., Nijv. en Handel [Duteh East Indies], Meded. Cultnnrtuin, No. 2 (1915), 

 pp. 32, pis. 4; abs. in Internat. Inst. Agr. [Rome], Internat. Rev. Sci. and Pract. 

 Agr., 7 (1916), No. 2, p. 198). — The author describes a number of plants (among 

 others, Tepfirosia Candida, T. hookeriana var. amwna, and T. vogelii; Centro- 

 sema pltimieri; Clitoria cajanifoli<i ; Desmodium gyroides; Indigofera hirsuta 

 and /. sumatrana; and Crotalaria striata) which gave good results when used 

 as green manure in the experiment garden at Buitenzorg, especially after the 

 alang alang (Imperata sp.) and weeds had been previously uprooted. 



Experiments carried out at the experiment garden and in plantations of Java 

 showed that " T. Candida gave better results than the other plants used as green 

 manure, especially in the Hevea, cacao, and tea plantations. Clitoria cajani- 

 folia can be recommended as preventing erosion on sloping ground. Cassia 

 pumila rapidly covers the ground and produces abundant foliage. It is to be 

 recommended for young plantations of rubber trees and of tea shrubs in order 

 to prevent erosion and the spread of weeds. Cassia tora has a subfrutescent 

 habit and grows as well on the seaboard as in the mountains." 



The author advises that the experiments be continued with Tephrosia sp.,, 

 Crotalaria, muyussi, D. hirsutum, and /. villosa by manuring crops other than 

 those growing in the Buitenzorg experiment garden. 



Loss of organic matter in green manuring, G. E. Boltz (Mo. Bui. Ohio Sta., 

 1 (1916), No. 11, pp. 347-350). — Plat and lysimeter experiments are described, 

 in which green clover was added to the soil at rates of 7,744 and 17,520 lbs. 

 per acre, being plowed under in two cases and left on the surface in two cases. 



It was concluded that an accumulation of a large amount of organic matter 

 does not take place as rapidly as is often assumed. " The loss of organic mat- 

 ter from a crop of clover which Is cut and allowed to remain on the surface of 

 soil for 206 days is practically the same as the loss of organic matter by 



