130 EXPERIMENT STATION EECOED. 



nitrogen that apparently remains in the soil after the removal of the first crop. 

 Nitrogen applied in the form of nitrate of soda and organic matter, half the 

 nitrogen from one and half from the other, gave a higher yield of dry matter 

 and a higher recovery of nitrogen than nitrogen which is all in the form of 

 organic matter. 



A comparison of sodium nitrate with ammonium sulphate, ammonium nitrate, 

 calcium cyanamid, calcium nitrate, dried blood, green rye, and alfalfa meal, when 

 added to buckwheat in sand in amounts equivalent to 308 mg. per pot showed 

 that the highest average yield was obtained with calcium nitrate and the nest 

 highest with ammonium nitrate. The lowest yield was obtained with calcium 

 cyanamid. In general, the percentage of nitrogen in the crop receiving organic 

 materials was lower than in those receiving mineral materials. The highest 

 recovery of nitrogen was with sodium nitrate and the next highest with calcium 

 nitrate. 



In pot experiments with buckwheat on a loam soil, using green manures, 

 sodium nitrate, and ground limestone, the purpose of which was to determine the 

 effect of ground limestone on the decomposition of organic matter, it was found 

 that in every instance the average yield of dry matter was higher with ground 

 limestone than without, whether used with green manure alone or with green 

 manure and sodium nitrate. Tlie percentage of nitrogen in the crop was in- 

 variably higher where sodium nitrate was used with the green crop, either with 

 or without lime. These results are ta*en to indicate that the limestone aided 

 the decomposition of the organic matter and increased the availability of the 

 nitrogen. 



In a final experiment with barley on a mixture of sjind and loam to determine 

 the effect of vegetable matter in the soil on the germination of seed and on the 

 growth of the crop and the effect of ground limestone on the decomposition of 

 vegetable matter, it was found that the ground limestone had a beneficial in- 

 fluence on the decomposition of the organic matter and in making the nitrogen 

 of this available. No effect of the vegetable matter was observed on germination. 



The influence of the mechanical composition of the soil on the availability 

 of nitrate of soda and dried blood, J. G. Lipmax, A. W. Blair. H. C. McL?:an', 

 and L. K. Wilkins (New Jersey Slas. lipt. 191Ji, pp. 226-236, pis. 3). — This is 

 an accoimt of a continuation during 1914 of experiments begun in 1011 (E. S. R., 

 S2, p. 516). 



It was found that sodium nitrate and dried blood when used on mixtures of 

 sand and shale soil, varying in proportion from 10 to 00 jier cent s;iud. gave 

 higher yields of dry matter and nitrogeu in the first crop than when used with 

 loam soil alone or sand alone. With the fir.st crop sodium nitrate invariably 

 gave higher yields than dried blood. " The average recovery of nitrogen ^\ith 

 nitrate of soda for the first crop was 00.52 and with dried blood 43.02 i)er cent. 

 The highest recovery with nitrate of soda was 71.17 i^er cent where the mixture 

 contained 70 per cent of sand, and the highest recovery for dried blood was 5r>.3 

 per cent with SO i>er cent sand. Taking 100 as the availability of the nitrate 

 of soda for this crop, the availability of the dried blood was 72.07. . . . In four 

 out of ten series no nitrate nitrogen was recovered in the second crop. and. with 

 one exceptiou, the recoveries from the other six were low. The average residual 

 recovery from dried blood for all series was 11.05 per cent." 



With reference to the total recoveries of nitrogen, the sodium nitrate stood 

 first in all cases, except where sand alone was used. In this respect the dried 

 blood showed an availability of S5.G0 when sodium nitrate is taken at 1(X). 



These results are taken to indicate that a marked residual effect can not be 

 exi)ected from a moderate application of sodium nitrate, but that some residual 

 effect may be expected from dried blood in nearly all cases. Mixing sand with 



