1920] SOILS — FERTILIZERS. 727 



that on certain soils treateil to liborai amounts of sodituii nitnito and siipfr- 

 phospliate. potasli in tlie fortilizer is less essential tlian wliere nitrate and 

 phosphate are sparingly applied, (G) the superiority in the first season of 

 sodium nitrate as the sole source of nitrogen as compared with amnioniuiu 

 sulphate and certain organic sources of nitrogen, constituting the whole or part 

 of the nitrogenous component of the fertilizer, and (7) the evident greater 

 influence at this stage of the more readily available forurs of nitrogt-n and phos- 

 phoric acid in comparison with those contained in organic substances. 



Studies on sources of nitrogen showed that dried blood failed to give any in- 

 crease in the potato crop, while sixlium nitrate, calcium nitrate, and annnoniuni 

 sulphate produced increases of from 30 to 50 bu. Whale guano did not ap- 

 preciably increase the yield of mangels and corn. 



Liming experiments sliowed the value of ground limestone when used in con- 

 junction with fertilizers and nianui'e. Three years' results fronr an exi)eriment 

 in which burned lime and ground limestone were used in varying quantities, 

 witli and without manure, showed that burned lime was about 12 per cent 

 more effective than the ground limestone equivalent. 



Analyses of limestones and miscellaneous fertilizer materials are reported. 



Fertilizers, G. A. Laxgalieb (Canada Expt. Farina Rpt. 1919, pp. 121, 122). — 

 A comparison of sodium nitrate witli ammonium sulpliate on a 3-year rotation 

 of potatoes, oats, and clover in the presence of a sufficiency of phosphorus and 

 potash showed that the potato crop was 3G per cent and the oats crop 1 per cent 

 greater when sodium nitrate was used, while with clover sodium niti'ate and 

 ammonium sulphate gave about equal results. 



A comparison of superpho-sphate, basic slag, and bone meal on a 3-year rota- 

 tion of potatoes, oats, and clover in the presence of a sufficiency of nitrogen 

 and potash showed that if 100 is takeu as the crop obtained from superpho.s- 

 phate, the crops obtained with the use of basic slag and bone meal were, respec- 

 tively, 50 and 47 for potatoes, 100 and 113 for oats, and 110 and 115 for clover 

 hay. 



Experiments on the fertilizing value of ground seaweed on a rotation of pota- 

 toes, oats, and clover showed that as a source of potas.sium, if 100 is taken as 

 the crop obtained by 1.500 lbs. of ground .seaweed, the crops obtained with the 

 use of 100 lbs. of muriate of potash were 128 for potatoes, 90 for oats, and 124 

 for clover hay. 



A comparison of burned lime with ground, limestone on a clayey loam soil of 

 bettor than average fertility with a 3-year rotation of oats, clover, and timothy 

 showed that if 100 is taken as the crop obtained with tile u.se t»f ground lime- 

 stone, the crops obtained with the use of burned lime were 102 for oats. 113 

 for oat straw, 106 for clover haj', and 110 for timothy hay, about the same 

 qimntities of calcium oxid being applied in both cases. When 15 tons of manure 

 were added to both, and 100 taken as the crop obtained with the use of ground 

 limestone, the crops obtained with the use of buriied lime were 120 for oats, 91 

 for oat straw. 107 for clover hay. and 95 for timothy hay. 



Fertilizer formulas for Georgia soils, J. N. Harpkr {Ga. Dept. Afjr.. Quart. 

 Bui. 82 iW20), pp. 9-15). — A list of formulas applying to general conditions 

 and farm practices is recommended for the different prevailing soil types of 

 Georgia. 



The preparation of mixed fertilizers for agriculture, F. A. Lui-kz Do- 

 MfNGiEZ (Porto Rico Dept. .\{/r. and Lahor f^ta. Circ. 19 (1919), [f^panish Kd.], 

 pp. 27). — This is a popular publication for Porto Rico farmers, containing in- 

 formation on the selection and mixing of fertilizers and outlining the functions 

 of and plans for assistance by the station in this connection. GenfP.il intormn- 

 tion on fertilizer and fertilizer materials is also given. 



