626 EXPERIMENT STATION RECORD. [Vol.43 



in the foi-m of clover tops in a soil containing only 625 lbs. of nitrogen per 

 2,000,000 lbs. of soil. One crop of soy beans and two crops of cowpeas were 

 grown. Some of the original soil was used each time for the treatment with 

 nitrates, but the same soils were used throughout the three crops for the 

 treatment with organic matter. 



The results indicate that nitrogen fixation will take place in a soil contain- 

 ing large amounts of nitrogen in the form of either nitrates or organic matter. 

 No injurious efCects on nitrogen fixation were caused by nitrates in this ex- 

 periment, and it is concluded that if such ever occur under similar condi- 

 tions, tlie application of nitrates must be many times larger than is ever ap- 

 plied in agricultural practice. It was found that nodules are produced when 

 large amounts of organic nitrogen are present in the soil, and good legume 

 growth results oven when sufficient organic matter is present to give large 

 losses of volatile nitrogen from the soils. The addition of some organic matter 

 may increase the amount of nitrogen fixed by cowpeas. In soils containing 

 varying amounts of total nitrogen, as much fixation of nitrogen by cowpeas 

 may be expected in one with 3,000 lbs. of total nitrogen as in one with lesser 

 amounts. According to the data, variations in the amount of total nitrogen in 

 a soil failed to exert any varying influence on the amount of nitrogen fixed. 



Some of the effects of the war upon fertilizers, L. L. Van Slyke (New 

 York State Sta. Bui. Jfll (1920), pp. 10). — A study is given of data regarding 

 commercial fertilizers collected in the State of New York during the years 

 1914-1919, showing that the number of complete fertilizers decreased each year 

 from 614 in 1914 to 171 in 1919. 



Mixtures of phosphoric acid and potash had practically disappeared by 

 1916, while mixtures of nitrogen and phosphoric acid appeared in relatively 

 large numbers in 1916 and the following years. Acid phosphate brands in- 

 creased, sodium nitrate, bone, blood, and tankage decreased, and potash salts 

 entirely disappeared. 



The average percentage of nitrogen in complete fertilizers decreased appre- 

 ciably after 1915, while that of potash decreased greatly after 1914 and still 

 more after 1916. The average percentage of available phosphoric acid in- 

 creased considerably after 1914, but with some variation from year to year. 

 The total percentage of available plant nutrients decreased continually after 

 1914. 



The average retail cost of 1 lb. of plant nutrient material in complete ferti- 

 lizers increased continuously from 8.8 cts. in 1914 to 33.1 cts. in 1919. The 

 retail cost of plant nutrient material in acid phosphate, sodium nitrate, bone, 

 dried animal manures, etc., increased, but not so much relatively as in the case 

 of complete mixed fertilizers.- 



High-grade fertilizers most economical, A. J. Patten (Michigan Sta. 

 Quart. Buh, 2 (1920), No. 4, pp. 179-181).— Practical information is given on the 

 sub.iect showing that, owing to the overhead expense of mixing and manu- 

 facture, it is advisable to purchase high-grade fertilizers. It is pointed out 

 that as the actual value of the fertilizer increases the overhead percentage of 

 cost decreases. 



Fertilizer work, W. G. Taggart (Louisiana Stas. Rpt. 1919, pp. 23, 2^). — 

 Fertilizer experiments with sugar cane showed the good effects of green ma- 

 nuring with clover together with applications of acid phosphate. Better results 

 were obtained with 500 lbs. of acid phosphate than with 250 lbs. when an equal 

 amount of nitrogenous fertilizer was used. Better results were obtained on 

 stubble than on plant cane. j 



