FERTILIZERS. 729 



recovered more or less rapidly, depending upon the conditions of temperature and 

 humidity of the medium, but independently of the proportion of lime. In sterilized 

 garden soil, however, the losses were much smaller, the constituents of the soil pos- 

 sessing an absorbent power for the ammonia, retaining under the conditions of the 

 experiment from 40 to 60 percent of the original nitrogen added. The amount (if 

 ammonia driven off from the soil was in direct relatiim to its richness in lime, the 

 temperature, and the humidity. If the soil was dry the elimination of ammonia was 

 more rapid, but the reaction was soon arrested and the quantity of nitrogen lost was 

 consequently less. In sandy media ])hosphatic slag caused a very rapid decompcjsi- 

 tion of the ammonium sulphate, due, evidently, to the free lime which this substance 

 contains. In the experiments on nitrification it was observed that the oxidation of 

 ammonia was quite slow in the rich garden soil, but the losses of ammonia were 

 insignificant. A part of the nitrogen escaped oxidation only when a large excess of 

 lime was added to the soil and the temperature raised. 



In the exi)eriments with barley grown on quartz sand and fertilized with ammonium 

 sulphate it was observed that with a medium ajiplication of lime nitrification was 

 slow, the losses of nitrogen were quite appreciable, the crop utilized only a part fif 

 the nitrogen, and the roots of the plants were injured by the ammonia salt. AVhen, 

 however, the conditions of the medium were more favorable to oxidation of ammo- 

 niacal nitrogen, the plants utilized a large part of the nitrogen and the yield was but 

 slightly lower than that obtained with nitrate of soda, although in a sandy medium 

 quite rich in lime ammonium sulphate is generally quite inferior to nitrate of soda 

 as a nitrogenous fertilizer. The fractional application of the nitrogenous fertilizer to 

 some extent favored fructification and increased the proportion of nitrogen in the 

 grain. 



It thus api:)ears that ammoniacal fertilizers can be used to best advantage on calcare- 

 ous soils under conditions favorable to nitrification and to the retention of ammonia, 

 such as occur in moist rich soils. In such soils, however, nitrification of the ammo- 

 nia is quite slow and the action of ammonium sulphate is for this reason much less 

 rapid than that of sodium nitrate, although much more durable in its effects. 

 Ammonium sulphate is not suited to use either on sandy soils without lime or on 

 such soils containing a large proportion of calcium carbonate. A light soil, in which 

 the proportion of lime does not exceed 5 to 20 per cent, may be benefited by ammo- 

 niacal fertilizers provided it is not subjected to drought. In this case also it is 

 desirable to apply the fertilizer fractionally during the earlier months of growth. If 

 the ammonium sulphate is to be used in connection with phosphatic slag, the latter 

 should be applied several days in advance of the former in order that the free lime 

 may become carbonated. 



A contribution to the question of liming, Schleykr {Deut. Landw. Presse, 29 

 {1902), No. 2, p. 12). — The benefi(;ial effect of liming on fruit trees is reported, and 

 an account is given of the different effects of iron sulphate solution on charlock 

 {Raplianux raphmuMrum) growing on soil deficient in lime and on that abundantly 

 supplied with lime. In the first ca.se spraying with 10 and 15 per cent iron sulphate 

 solution produced no result, while in the second case a spray of 10 per cent solution 

 quickly killed the weed. It is suggested that on the soil deficient in lime the jilaiits 

 contained an excess of oxalic acid and this prevented the reaction between the iron 

 sulphate and the tannic acid of the plant, resulting in bla(;kening and death. 



Fertilizer experiments with lime and marl, P. Hillmann [Mitt. Deut. Landw. 

 Gesell, 16 {1901), Nos. 44, PP- 256-25S; 4t>, PP- 265, 266; 47, pp. 272, 273; 48, pp. 

 275-278; 49, p. 281; 50, pp. 284-287). — Cooperative experiments in different parts of 

 Germany are reported. These showed in the majority of cases the need and value 

 of liming and marling. On heavy soils containing as much as 0.5 per cent of lime 

 the application of the latter was beneficial. 



