1910] SOILS FERTILIZERS. 721 



iiodule formation, in tlie case of iuucuiation witli foreign strains gave clear 

 evidence of stimulation of growth by nonsynibiotic nitrogen tixation botli by 

 azotobacter and nodule organisms. The practice of pitting and rotting a green 

 manure crop before applying it to the land has been found to give crops as 

 good as those raisetl after green manuring in the usual way. 



Studies on the phosphate requirements of soil bacteria led to the conclusion 

 that " increase in available phosphoric acid greatly increases the general bac- 

 terial activity of a soil, and therewith the formation of carbon dioxid. There is 

 a positive relation between the amounts of carbon dioxid thus foinued and the 

 solubilization of phosphate in the soil, but this varies with the character of the 

 latter." Addition of soluble phosphate inci'eased the ammonification rate in 

 all the soils examined. Addition of phosphate in many cases diminished the 

 nitrification rate, apparently owing to the disproportionate increase in non- 

 nitrifying organisms. The final result over long periods of time in most cases 

 showed no increase in the total nitrate formed. 



Studies on the nitrogen content of liquid manure, II— IV, E. Blanck 

 (Lanclw. Vers. Sta., 91 (1918), No. 5-6, pp. 253-269, 271-290, 309-3^6) .—Theae 

 three articles explain more in detail experiments previously noted (E. S. R., 

 40, p. 723). 



II. The transformation of the nitrogen of urine in soil. — Studies on the 

 chemical and bacteriological transformation of the nitrogen of liquid ma- 

 nure In light sandy soil are reported, in which it was found that bacterial 

 decomposition of urine in sandy soil began very quickly. While this action 

 was somewhat retarded by phosphate treatment, eventually the loss of nitrogen 

 through the formation of ammonia assumed large proportions. This led to 

 the conclusion that the conservation of liquid manure with acids is unprofit- 

 able. No nitrification of the ammonia formed was observed, this being attrib- 

 uted to the deficiency in lime of the sandy soil. It was found that during 

 nine weeks nearly 75 per cent of the total nitrogen in urine added to sandy 

 soil was lost. It is concluded that the use of liquid manure on light sandy 

 soils deficient in lime is not to be recommended. 



III. The loss of nitrogen from liquid manure and urine due to their use as 

 top-dressings. — Experiments on the loss of nitrogen from urine and liquid 

 maimre when used as a top-dressing on light sandy soil and when mixed into 

 the soil are reported. 



It was found that the greatest loss of nitrogen from urine and liquid manure 

 took place during the time of addition and the sinking of the liquid into the 

 soil. Smaller losses took place through evaporation and escape of free nitro- 

 gen while the liquid lay In the soil. The washing out of nitrogen from the soil 

 by atmospheric movement is not considered great. A nitrogen loss due to the 

 evaporation of urine or manure liquid was also observed, the older the urine 

 the greater being the loss of nitrogen. Mixing the liquid under the soil pre- 

 vented tlie nitrogen losses only partially, but the losses decreased as the depth 

 of mixing increased. Treatment of urine and liquid manure with sulphuric 

 acid was found to be a better method of preventing nitrogen losses. 



IV. Tlw influence of formalin and sulphuric acid on the conservation and 

 fertilising action of liquid manure nitrogen. — Studies are reported in which 

 it was found by cropping experiments that liquid manure neutralized with sul- 

 phuric acid gave as good results as ammonium sulphate. The liquid manure 

 kept in air gave considerably poorer results than the liquid neutralized with 

 sulphuric acid and the ammonium sulphate, but gave much better results than 

 liquid manure treated with either 5 or 10 per cent formalin solution. Liquid 

 manure treated with formalin gave very poor results with reference to its 



