SOILS FERTILIZERS, 317 



and potash as muriate of potash, 3 gm. per jar. Kubanka durum wheat was 

 the crop used in the experiments. 



The results show that wherever nitrogen was added, whether on virgin or 

 cultivated soil, there was a decided increase in yield, the increase being more 

 iiiarlced, however, on the cultivated soil. Phosphorus produced a very satis- 

 factory Increase on both virgin and cultivated soils, and as with nitrogen, the 

 increase was greater on the cultivated than on the virgin soil. Potash in- 

 creased the yield to some extent, though not so much as phosphorus. Nitrogen 

 and phosphorus combined produced a greater increase than would be expected 

 from their effect when applied alone. It is suggested that this was due "to 

 tliemical reaction between the two fertilizers by which they were made more 

 readily available." No considerable benefit resulted from combination of phos- 

 phorus and potash. " The use of manure gave a better result than did the use 

 of either phosphorus or potassium, but the result was considerably less than 

 when nitrogen was added. . . . However, the manure used was not so rich in 

 fertility as that usually used in such experiments, much of the nitrogen having 

 no doubt escaped." 



The results in general show that the greatest need of these soils is nitrogen, 

 and that this need increases under cultivation. It is suggested that the most 

 economical method of supplying this need is by the culture of leguminous crops. 

 The purchase of commercial fertilizers except in a small way to be used in 

 testing the soil is not at present reconnuended. 



A study of Rhode Island soil requirements by means of field tests, G. B. 

 Adams {NIkxIc Lshiiid t^ta. Bui. 121, pp. 139-17')). — An account is given in this 

 bulletin of 15 cooperative experiments conducted during the season of 100<i on 

 4 different soil types of Rhode Island, namely, Gloucester stony loam, Miami 

 stony loam, Warwick sandy loam, and Alton stony loam, to determine the 

 fertilizer requirements of the soils and to compare the results obtained in field 

 experiments with those obtained on the same soils by the wire-basket method 

 of the Bureau of Soils of this Department (see below). The crops grown were 

 purple-top turnip in 14 trials, Swedish turnip in 7 trials, and spring wheat in 

 12 trials. 



" From the results obtained from this series of experiments, conducted for 

 one season, there appears to be no I'elation between the soil type and the plant 

 food requirements of a given soil. . . . 



" Hydrated lime often exerts an injurious effect upon certain crops, when 

 grown upon the lighter soils, if applied immediately before the seed is sown, 

 even though the soil reddens blue litmus paper. This caustic action upon the 

 roots of yoinig plants is, however, only temporary, as shown by the benefit de- 

 rived from liming, by croi)s the seed for which was sown a few weeks after 

 aii])lying the lime. No appreciable difference was noted in the benefit derived 

 from an application of the same quantity of calcium oxid, whether in the form 

 of ground limestone or in hydrated lime." 



Soil tests in paraffined wire baskets compared with tests on farms, R. L. 

 llARTWKLL and C. L. Cook (Rhode Inland ma. Bui. 1.20, pp. 109-138, pis. 2).— 

 This is a report on cooperative experiments with the Bureau of Soils of this 

 Department in which soils from 15 different localities in Rhode Island were 

 tested with wheat by the wire-basket method of the Bureau " to ascertain the 

 effects of lime, of a complete fertilizer with and without lime, and of omitting 

 I»otassium, phosphorus, or nitrogen from the complete fertilizer when used with 

 lime," and to compare the results obtained by this method with those obtained 

 in field experiments on the same soils in place. Some of the soils were also 



