218 EXPEKIMENT STATION KECORD. [Vol.35 



It was found that all the manganese salts used produced an increase in 

 the beet root yield. The most favorable influence was exerted by the man- 

 ganese phosphate in all amounts added and by the combination of manganese 

 sulphate with aluminum sulphate. The small additions of manganese nitrate 

 produced the greatest increases. All increases in yield are attributed only to 

 the stimulating influence of the manganese. 



A second set of pot experiments on a productive cultivated soil to determine 

 the influence of a radio-active fertilizer on the growth of oats, white mus- 

 tard, and peas when added in amounts of 0.4, 0.8, 1.6, and 4 gm. per 21 

 kg. of soil in zinc pots, and in amounts of 0.23, 0.46, 0.92, and 2.3 gm. per 

 13 kg. of soil in clay pots, is reported. It was found that the radio-active 

 fertilizer was especially active in stimulating fruit formation and that this 

 influence was exerted without an undue exhaustion of the nutritive con- 

 stituents in the soil. No injury to the crops through the larger additions of 

 the radio-active fertilizer was observed. 



The influence of certain org'anic materials upon the trausformation of soil 

 nitrogen, R. C. Weight {Jour. Amer. Soc. Agron., 7 {1915), No. 5, pp. 193-208, 

 flgg 7). —Experiments on the influence of dried, fresh, and rotted stable manure, 

 mature wheat straw, starch, cellulose, glucose, dextrose, and green manures 

 on nitrogen in the forms of ammonium sulphate, potassium nitrate, and pep- 

 tone and on the original nitrogen in sandy and clay loam soils, greenhouse 

 bench soil, orange grove soil, and silty loam soil are reported. 



From the results the conclusion is drawn " that in agricultural practice the 

 plowing under, in an undecayed state, of straw or stra\vy material such as 

 old hay, litter, leaves, stalks, strawy manure, fresh stable manure, and even 

 green manures or cover crops that have been allowed to become mature or 

 nearly so, will serve to reduce the quantity of available nitrogen in a soil. 

 When such a practice is followed only during fall plowing and in a region 

 with a fairly open winter ... a sufiiciently advanced stage of decomposition 

 would be reached by spring not to interfere with normal nitriflcation. . . . 

 Plowing under of green manur<^3 presents a different problem because very 

 little resistant cellulose material is added. Such succulent green material is 

 readily attacked by saprophytic micro-organisms and rather rapid decay ac- 

 companied by vigorous nitrification takes place, thus maintaining the supply 

 of available nitrogen." 



The fixation of nitrogen in stable manure, Geelach (Ztschr. Ver. Devi. 

 Zuckerindus., No. 717 {1915), II, pp. 5^.7-554, fig. i).— The results of several 

 experiments are briefly reported which indicate that the addition of super- 

 phosphate, certain potash salts such as kieserit, or acid salt by-products from 

 chemical industries to liquid manure in amounts suflicient to produce an acid 

 reaction will cause a marked reduction in nitrogen losses. A film of oil 

 over the top of liquid manure had the same effect. Everything considered, 

 however, the best results were obtained from the use of superphosphate. 



Fertilizer experiments with different ammonium salts in Weihenstephan 

 in 1915, Ahk {Mitt. Dcut. Landw. Gesell., 30 {1915), No. 46, pp. 696-699). — 

 Field experiments with early potatoes and with rotations of wheat, oats, and 

 potatoes and potatoes, wheat, and beets on marly loam and deep mild loam 

 soils to compare the fertilizing value of ammonium chlorid, ammonium carbo- 

 nate, ammonium-sodium sulphate, ammonium nitrate, ammonium sulphate, 

 sodium nitrate, calcium nitrate, and lime nitrogen with nitrogen contents of 

 23.1, 16.76, 7.65, 34.2, 19.9, 16.01, 12.64, and 19 per cent, respectively, are re- 

 ported. The fertilizers were added in amounts equivalent to 30, 45, and 60 kg. 

 per hectare (26.7, 40, and 53.4 lbs. per acre) of nitrogen. 



