320 EXPERIMENT STATION RECORD. [Vol. 37 



tain plants. Thus, in the greenhouse toluene and carbon bisulphid had the 

 best influence on tomatoes. These results are thought to justify the conclusion 

 that the treatment of soils with antiseptics is, on the whole, beneficial. 



Chemical studies of the efficiency of le&umes as green manures in Hawaii, 

 Alice R. Thompson (Haicaii Sta. Bui. 4S (1917), pp. 26).— The results of the 

 first year's experiments to determine the comparative values for soil improve- 

 ment of 32 different varieties of legumes on a rich bro\vn calcareous soil from 

 the station grounds and a red, apparently acid, soil low in phosphate and lime 

 from Kunia are reported. 



It was found that " the nitrate content of soils in which legumes are growing 

 is low as compared with unplanted check soils, owing possibly to absorption of 

 nitrates by the roots of the growing plants. Where a large amount of legumi- 

 nous growth is turned under to decompose, the nitrate content of the soil usu- 

 ally is greatly increased. 



" Legumes grown on station soil usually showed a higher percentage of nitro- 

 gen in the water-free material than those grown on Kunia soil. Liming in a few 

 cases increased the nitrogen content and the nodule development of legumes on 

 Kunia soil. The nitrogen content of the above-ground parts of legumes, 

 although more variable than that of roots, was also usually greater, especially 

 on the station soil, where only the velvet bean and German lupine gave the 

 same value for plant and roots, owing possibly to the large bunches of nodules 

 on their roots. . . . 



" In calculations of nitrogen in the entire legume plant on a water-free basis 

 the plants grown on Kunia soil again appear deficient in this element. Liming 

 increa.sed the nitrogen content of the entire plant in case of the jack bean and 

 cowpea, but not of the velvet bean. The crotalarias contained the most nitro- 

 gen on both a fresh and water-free basis. As green manure, Sesbama ccgyptiaca 

 and the velvet bean might be used successfully on Kunia soil if a lime dressing 

 is employed. 



" The results of analyses indicate that the nitrogen of leguminous plants is 

 gained through atmo.spherlc assimilation and not from the soil. 



" When a legume is to be grown for turning under the roots only, the per- 

 centage of nitrogen in the roots and the weight of roots per acre should be 

 considered. The varieties which gave the heaviest yield of root nitrogen per 

 pot were the cowpea, velvet bean, jack bean, Mauritius bean, alfalfa, Jn- 

 digofcra anil, and Phascolug seviicrcctus grown on station soil. 



" From the results obtained in beaker experiments. It appears that one-fifth 

 of the total nitrate nitrogen of cowpeas Is converted into .soluble ammonia and 

 nitrate salts lu three weeks' time. In pot experiments, where the conditions 

 more nearly represented those In the field, in the station soil pots one-half the 

 nitrogen decomposing cowpeas and jack beans was lost through weathering. 

 In Kuula soil a loss of nitrogen was also observed in case of these legumes 

 and also of velvet beans and soy beans, which showed no loss from weathering 

 In station soil, probably because of their later maturity and consequently 

 shorter period of weathering. It appears that In the field, with heavy rains or 

 Irrigation, considerable loss of nitrogen probably results through the leaching 

 of soluble ammonia compounds and nitrates from decomposing legumes. It 

 would be advisable, therefore, to follow the turning under of leguminous crops 

 In field soil by the growth of a crop which would utilize the soluble nitrates and 

 ammonia salts formed from the nitrogen of the legumes before they are lost 

 by drainage." 



Tests of the value of stable manure, commercial fertilizer, and crimson 

 clover for vegetable crops, T. H. White (Maryland Sia. Bui. J99 (1916), pp. 

 9S-106). — Experiments begun in 1904 to determine the comparative lasting 



