534 EXPERIMENT STATION RECORD. 



It was found thai about half of the carbon of the sewage disappeared during 14 

 days, part in form of gas and part deposited in insoluble form. During the same 

 period about 64 per cent of the organic nitrogen disappeared, but the amount of 

 ammoniacal nitrogen increased, the total loss of nitrogen being about 8 per cent. A 

 study of the relative rate of decomposition of the solid matter of the sewage in cov- 

 ered and uncovered tanks showed very slight differences as regards the efficiency of 

 aerobic and anaerobic fermentation in dissolving the solid matter. 



SOILS FERTILIZERS. 



The gist of four years' soil investigation in the Illinois wheat belt, C. G. 

 Hopkins, J. H. Pettit, and J. E. Readhimer (Illinois Sta. Circ. 99, pp. 4). — 

 The sources of supply of nitrogen, potassium, and phosphorus for wheat crops grown 

 on the soils of this region are described, and the results of 4 years' experiments with 

 different fertilizers, showing a profit only in case of applications of commercial phos- 

 phates, are briefly summarized. 



The gist of four years' soil investigation in the Illinois corn belt, C. G. 

 Hopkins, J. H. Pettit, and J. E. Readhimer (Illinois Sta. circ 100, pp. 4). — The 

 sources of supply of nitrogen, potassium, and phosphorus for corn crops grown on 

 the soils of this region are described, and the results of 4 years' experiments with 

 different fertilizers, showing a profit only in case of applications of commercial phos- 

 phates, are briefly summarized. 



Contribution to the solution of the question of the water content of the 

 soil and the water requirements of plants, C. von Seelhorst and Muther (lour. 

 Landw., 53 (1905), No. 3, pp. 239-259). — This is an account of a continuation during 

 1904 of similar work carried on in previous years (E. S. R., 16, p. 856) and records 

 results of observations on soils under oats, clover, and bare fallow in large cylinders 

 (\\ cubic meters contents) sunk in a trench and so arranged that they can be 

 weighed at regular intervals. In case of the oats the surface soil of one cylinder was 

 kept stirred between the rows, while that of a second cylinder was compressed by 

 rolling. 



A detailed record is given of the rainfall, the hours of sunshine, and temperature 

 of the air and soil, as well as of the changes in weight of the cylinders. The total rain- 

 fall during the period of growth of the oats was 109.8 mm. Of this, all w r as evaporated 

 except 20.8 mm. in the case of the cultivated soil and 30.4 mm. in the case of the 

 rolled soil. Of the 67.9 mm. of rainfall received by the clover up to the time of the 

 first cutting, 47.2 mm. was evaporated. 



The water requirements of both oats and clover were very much in excess of that 

 supplied by rainfall during the growing season, hence the water supply of the soil 

 derived from previous winter rains was drawn on. In case of oats grown on cultivated 

 soil, 1 gm. of dry matter required 256.7 gm. of water, on rolled soil 270.2 gm. While 

 the absolute amount of water required in case of oats grown on rolled soil was smaller 

 than that of oats grown on cultivated soil, the relative amount was larger, due to the 

 smaller yield on the rolled soil. 



This lower yield on rolled soil is ascribed to poorer aeration, resulting in slower 

 transformation of plant food and interference with root transpiration and not to lack 

 of water. One gram of dry matter in the first cutting of clover required 423 gm. of 

 water, in the second cutting 1,124 gm. There was very little drainage water in case 

 of the cropped soils, and the loss of nitrogen in this way was very small, 6 kg. per 

 hectare I -"").34 lbs. per acre) under oats and 11.8 kg. per hectare (10.51 lbs. per acre) 

 under clover. The amount of drainage water from the bare soil was much larger and 

 the loss of nitrogen in this way was 60 kg. per hectare (53.44 lbs. per acre). 



The hygroscopic capacity of soils, C. M. Luxmoore (Jour. Agr. Sci., 1 (1905), 

 No. ?, pp. 304-321). — This article reports laboratory studies of the capacity of soils to 



