SOILS FERTILIZERS. 325 



" With the residual crop some nitrogen was recovered where blood was used 

 in each of the ten series. The decline in the recovery with increased quantities 

 of sand was very gradual. 



" In the residual crop the yield of dry matter was lowest with nitrate of 

 soda, and highest with blood. The yield from the check cylhiders would ap- 

 proximate an average of the other two. 



" From this worii it seems safe to conclude that it is needless to expect any 

 residual effects from moderate applications of nitrate of soda on open sandy 

 soils. Some residual effects may be expected on such soils from dried blood or 

 other organic fertilizers of a similar character. 



" The actual net recovery of nitrogen from the humus of the shale soil, 

 which contained varying proportions of sand, Is greater iu nearly every case 

 than the theoretical amount as calculated from the recovery from pure shale 

 soil. Mixing sand with heavy shale soil permits better aeration and drainage, 

 and results in a more complete utilization of the nitrogen that is present." 



Experiments on the accumulation and utilization of atmospheric nitrogen 

 in field soils, J. G. Lipman, A. W. Blair, I. L. Owen, and II. C. ^McLean (New 

 Jersey Stas. Bui. 258, pp. 3-24; I^Pt- 1012, pp. 248-269).— One series of experi- 

 ments reported iu this bulletin was conducted on twentieth-acre plats of gravelly 

 clay loam deficient in nitrogen, the object being " to study the influence of small 

 quantities of cow manure and of the bacteria in it on the decomposition of green 

 manures." Corn was followed by crimson clover and rye as green manures to 

 which were added in different series 50, 100, and 200 lbs. of well-rotted manure 

 broadcast over the green manure before plowing under. Wheat was then seeded. 



There was no appreciable improvement of the first crop (corn) in 1908 on 

 manured plats, " In the crops for 1909, 1910, 1911, and 1912 there was with 

 only slight exception a better yield of both dry matter and nitrogen on the 

 plats that received manure than on the check plats. However, the plats that 

 received the most manure did not, in many instances, give the largest yield. 

 On the contrary, the plats that received the smallest application of manure did, 

 in a number of instances, give the largest yields. It therefore appears that the 

 beneficial effects of the manure were physical and biological rather than 

 chemical." 



As a rule the plats green-manured with a legume gave a larger yield and 

 crops richer in nitrogen than those green-manured with rye. 



In a second series of experiments wheat and rye were grown continuously 

 with and without legumes. 



Comparing the 1909 yield of grain, total dry matter, and total nitrogen from 

 the nonlegume plats, both wheat and rye, with those for the 1910, 1911, and 1912 

 crops there is shown a falling off in yield. On the legume plats there was 

 practically no loss in any case and substantial gains in some iu.stances. " This 

 clearly indicates an improved condition of the soil and shows that it is not 

 only not losing in fertility, but that it is slowly gaining. That is, the nitrogen 

 supply is being kept up by the legume crop, while the land is being continually 

 cropped to rye and wheat. The nonlegume plats are gradually becoming poorer 

 in nitrogen. Without the application of stable manure or commercial nitrog- 

 enous materials, the legume plats are producing at the rate of 22 to 30 bu. of 

 gi'ain per acre, are apparently gaining in nitrogen and therefore in humus, and 

 are each year assuming a better mechanical condition, with an extra cost over 

 the nonlegume plats of only about $4.50 per acre," 



Peculiarities regarding the nitrate formation and the nitrate content in 

 moor soil, G. A, Rittee (Internat. Mitt. Bodcnk., 2 (1912), Xo. 5, pp. 411-428).— 

 An investigation of the relations between nitrate formation and nitrate content 

 in moor soils is reported. 



