FERTILIZERS. 941 



The results of comparative tests of drainage of upland moors to 

 depths of 50 to 150 cm. indicate that for potatoes and rye, which are 

 the principal moor crops, a depth of 50 cm. gives the best results, 

 especially for new soils. As culture continues the depth of drainage 

 may be increased without injury. 



Burnt lime, marl, chalk, and gypsum in varying amounts were com- 

 pared on a number of different crops and upland moor soils. The 

 results indicate that as a rule these manures increased the productive- 

 ness of the soil principally by improving the porosity and drainage of 

 the soil and thus increasing the depth to which the roots of plants 

 could descend. 



In experiments on the action of different forms and amounts of potash 

 and phosphoric acid on upland and lowland moor meadows it was 

 found that combinations of kaiuit and Thomas slag gave an increased 

 yield when other conditions of growth were favorable. Crude phos- 

 phates were found to be very effective when considerable amounts of 

 acid were present in the soil. The character of the grasses was much 

 improved by the use of fertilizers. An improvement was also noted in 

 the composition of the individual grasses grown on the fertilized soil. 

 This was shown in an increase in the percentage of protein. The 

 grasses grown with fertilizers contained a higher percentage of water 

 thau those grown without fertilizers. The dry matter of the hay 

 grown on fertilized soils contained higher percentages of potash and 

 phosphoric acid than the averages given by Wolff. Hay from the 

 lowland moors contained 2.17 per cent of potash and 0.57 per cent of 

 phosphoric acid, while that from the upland moors contained 1.95 per 

 cent of potash and 0.79 per cent of phosphoric acid. 



Pot experiments on moor soils at the Moor Experiment Sta- 

 tion at Bremen, B. Tacke and H. Immendorff (Landw. Jahrb., 27 

 (1898), Sup. I, pp. 259-300, pis. 19, Jig. 1). — Accounts are here given of 

 pot experiments with upland and lowland moor soils, including tests of 

 nitrogenous and phosphatic manures on lowland moor soils, studies on 

 the optimum water content of upland and lowland moor soils, and on the 

 action of underground liming and of naturally occurring compounds of 

 phosphoric acid and iron on upland moor soils. 



The experiments with nitrogenous fertilizers on lowland moor soils 

 showed that even in cases in which the soil contained from 2.52 to 3.39 

 per cent of nitrogen the yields of oats, rye, and sugar beets were 

 greatly increased by applications of nitrogen. The more favorable the 

 conditions for nitrification and the more rapid tin's process took place 

 in the soil the less the benefit from nitrogenous fertilizers. 



In experiments on the action of phosphoric acid on lowland moor 

 soils containing varying amounts of phosphoric acid, applications of 

 phosphoric acid ceased to increase the yield of oats when the soil con- 

 tained 0.44 per cent of phosphoric acid, and were without effect on the 

 yield of wheat when the amount present in the soil was 1.23 per cent. 



