1917] SOILS FERTILIZEES. 425 



while in another soil they are destroyed by oxidation or other life processes 

 of the soil and do not remain to have an influence on soil productivity." 



Soil fertility (North Dakota Sta. Rpt. 1916, pp. 4, 5). — A comparison of 

 rotted stable manure with fresh manure and a combination of fresh manure 

 and steamed bone meal gave results confirming those reported in Bulletin 100 

 (E. S. R., 28, p. 338). 



" Four years' data from the milling of the wheats from lands treated with 

 rotted manure, with fresh manure, with combination of fresh manure and 

 steamed bone meal, and without treatment of any character, do not show strik- 

 ing differences that could be attributed to the use of manures. Cost data for 

 the trial indicate that potassium and phosphorus fertilizers can not as yet 

 be profitably used on the black clay soil." 



Plat experiments comparing steamed bone meal, acid phosphate, and raw 

 rock phosphate, in which stable manure and crop residues were also added to 

 the soil, showed that on the basis of four-year averages " the commercially 

 fertilized plats have not given a lax'ger gross income than the plats on which 

 stable manure was used. If the cost of the phosphorus fertilizer is deducted 

 from the total income received from crops, a less return was obtained than 

 from the manured plats. The income derived from the various treatments was 

 nearly uniform. No form of phosphorus yielded markedly superior returns in 

 this trial. Comparatively, acid phosphate made a slightly better showing than 

 steamed bone meal or rock phosphate." 



The use of fertilizers to increase crop production, E. B. Stookey (Washing- 

 ton Sta., West. Wash. Sta. Mo. Bui., 4 (1916), No. 9, pp. 5-9, figs. 2).— This is 

 a brief note based on experience at the substation on the use of fertilizers and 

 manure and especially on the value of manure as compared to other fertilizers. 

 Experiments with potatoes, kale, mangels, and corn on muck, sandy loam, 

 and shot clay soils showed that in all cases manure alone at the rate of 15 

 tons per acre produced greater increases in yield than sodium nitrate, super- 

 phosphate, potassium sulphate, ground lime rock, gj^psum, and a complete 

 fertilizer applied at respective rates of 100, 200, 200, 4,480, 200, and 450 lbs, 

 per acre. 



Improvement of hill and peaty pastures (Univ. Col. N. Wales, Bangor, 

 Dept. Agr. [P«6.] 5 (1915), pp. 2-6). — Experiments on the treatment of poor 

 pasture on hilly loam soil and on acid and neutral peat soils are reported. Seven 

 :i-acre plats were used, the treatment per acre being as follows: No manure, 

 1,000 lbs. of basic slag, 1,000 lbs. of groiind Gafsa phosphate, 600 lbs. of super- 

 phosphate, 600 lbs. of superphosphate and 1 ton of ground lime, 1 ton of 

 ground lime, and 8,600 lbs. of ground limestone. Each plat received in addition 

 to the treatment mentioned, 150 lbs. of potassium sulphate or 600 lbs. of 

 kainit. 



The results indicated that basic slag Is likely to produce at least as good a 

 result as any other manure or mixture of manures on these soUs. Gafsa phos- 

 phate (raw mineral phosphate) produced almost as good an effect as basic 

 slag on acid peat soils. In no case was a return given by potash manure 

 at all commensurate with its cost, the effect produced being negligible in almost 

 every case. Lime and ground limestone had practically no effect, although in 

 many cases the soil was acid. 



The necessity for guano in national agriculture ( Las Necesidades de Guano 

 de la Agricvltura NacionaZ. Lima: Compaiiia, Admin. Guano, 1916, pp. 4S2, pis. 

 85). — This report deals with Peruvian agriculture with special reference to the 

 use of guano as a fertilizer. 



Factors affecting the absorption and distribution of ammonia applied to 

 soils, K. C. Cook (Soil Set., 2 (1916), No. 4, PP- S05-3U, fig»- 7).— Experiments 



