SOILS FERTILtZEES. 211 



Soil tank investigations, S. E. Collison {Florida Sta. Rpt. 1912, pp. XLIII- 

 XLVII). — Studies of the chemical composition of the drainage water from 

 soil tanks used in fertilizer investigations with oranges were continued (E. S. 

 R., 27, p. 320) and the losses of fertilizing constituents indicated by the analyses 

 are discussed. The tanks received 2 lbs. three times a year of a fertilizer 

 mixture containing 5 per cent of ammonia in various forms, 6 per cent of phos- 

 phoric acid in form of superphosphate, and 6 per cent of i)otash in form of 

 sulphate. 



Of the total rainfall (44.58 in.) 36.7 per cent appeared in the drainage. 

 The nitrogen in the drainage water was almost entirely in the form of nitrate 

 and the amount was greater where sodium nitrate was applied than where 

 ammonium sulphate was used. In some cases the loss was greater with dried 

 blood than with ammonium sulphate. The loss of potash in the drainage has 

 sho%vn a slow increase from the beginning but is stUl very small. The loss 

 of phosphoric acid was found to be extremely small, but was slightly increased 

 by the application of superphosphate. Lime and magnesia appeared in the 

 drainage water in fairly large amounts. 



Tank experiment for 1910, E. G. Schollandeb (North Dakota Sta., Rpt. 

 WilUston Substa., 1910, pp. 53-66, fig. 1). — A continuation of experiments car- 

 ried on in cooperation with this Office at the Williston substation is reported. 

 It was found that evaporation was greatest from the uncultivated tanks, but 

 that tanks cultivated 6 in. deep lost more water by evaporation than those 

 cultivated 2 and 4 in. deep. The uncultivated tanks were several degrees 

 warmer than the cultivated tanks. The lowest average temperature was 

 observed in tanks cultivated 2 in. deep. The growing of a crop of corn in- 

 creased the loss of moisture from the soil, notwithstanding the fact that the 

 soil was cultivated to conserve moisture. There was more moisture in the 

 upper 3 ft. of straw mulched .soil than in cultivated soil. There was prac- 

 tically no difference in the fourth foot of soil, and in the fifth and sixth foot 

 there was more moisture in the cultivated soil than in the mulched soil. Plow- 

 ing and harrowing increased the moisture content of the surface soil. 



Moisture conservation by tillage and cropping, E. G. Schollandeb and 

 W. Whitcomb (North Dakota Sta., Rpt. Williston Suhsta., 1911, pp. 54-60).— A 

 progress report is given on the effect of fall and spring plowing, continuous 

 cropping and alternation with fallow, and disking stubble after harvest on the 

 moisture content of the soil. 



Nitrogen enrichment of soils, F. T. Shutt (Canada Expt. Farms Rpts. 1912, 

 pp. lIfJi-lJi6, pi. 1). — This is a report of a continuation of observations on the 

 increase of nitrogen in the soil as a result of the growth of clover (E. S. R., 

 27, p. 322), summarizing data obtained during 10 years. It is shown that the 

 nitrogen content of the soil has been increased during this period 511 lbs. per 

 acre to a depth of 4 in. 



The intensity of nitrification in arid soils, R. Stewabt (Proc. Amer. Soc. 

 Agron., 4 (1912), pp. lS2-lJf9). — The investigations here reported have already 

 been noted from another source (E. S. R., 29, p. 21). 



The fixation of nitrogen by so-called zeolites, G. Wiegneb (Jour. Landw., 

 61 (1913). No. 1, pp. 11-56, pis. 2, fig. 1) . — ^The experiments reported showed 

 that the addition of small amounts of calcium-potassium permutite, which had 

 been saturated in a solution of ammonium chlorid, increased the yield of dry 

 matter of oats as well as of the following crop of buckwheat but had little 

 effect upon the total amount of nitrogen assimilated in either case. There was, 

 however, a marked increase in the nitrogen assimilated by the grain as com- 

 pared with other parts of the plant, and an increase in dry matter was also 

 most marked in case of the grain. This effect was apparently due to the fact 



