SOILS- — FEETILIZE-KS. 425 



magnesia taken up by cliffereut cultivated plants, the action of green manures 

 and tbe utilization of the nitrogen of such manures, the comparative action of 

 sodium nitrate, ammonium salts, lime nitrogen, and Norwegian nitrates, the 

 comparative action of kainit, 40 per cent potash salt, and phonolite, and special 

 fertilizers for the production of beet seed. 



These experiments have been carried on since 1902, the crops grown including 

 sugar beets, barlej^ wheat, oats, and potatoes. A large amount of data bearing 

 upon the effects of the various fertilizer and manure combinations are given in 

 tables. 



The results show in general that manure alone was a very effective fertilizer 

 and that profitable increases in yield were obtained with various combinations 

 of the commercial fertilizer. In the case of root crops, especially, the highest 

 yields were obtained by the addition of mineral fertilizers to the stable manure. 

 The yield was also increased in this way in the case of barley following beets. 



The sugar beets assimilated the highest percentage of the plant food of the 

 fertilizers, potatoes being second in this respect. However, assimilation of 

 plant food and increase in yield did not run parallel. The potash of the stable 

 manure was more thoroughly assimilated than the nitrogen and phosphoric 

 acid, these being taken up in about equal proportions. 



On the fallow plats there was a decided loss of nitrogen notwithstanding the 

 application of stable manure and mineral fertilizers. Thei'e was a loss of potash 

 where either minei'al fertilizer or stable manure was applied alone, but an 

 increase when a combination of the two was used. There was an increase in 

 the phosphoric acid in all cases. Green manures gave an increased yield in 

 every case, and the addition of nitrogenous fertilizers to the green manure gave 

 no result except in case of beets. 



The best results were obtained with sugar beets by plowing the land as early 

 as possible, but with potatoes it was best to leave the land fallow until fall. 

 It is thought that this difference is due to the depth to which sugar-beet roots 

 penetrate into the soil, enabling this crop to reach the nitrogenous compounds 

 washed into the lower soil, and which in the case of potatoes would be unavail- 

 able on account of the shallow roots of this crop. 



In comparative tests of different forms of nitrogenous fertilizers ammonium 

 sulphate was 90 per cent as effective as sodium nitrate in increasing the yield, 

 although the percentage of nitrogen assimilated from the ammonium salt was 

 only 82 per cent of that utilized from the nitrate. The Norwegian (basic) lime 

 nitrate was 96 per cent as effective as sodium nitrate in increasing the yield, 

 and the assimilation of the nitrogen of this material was slightly greater (103 

 per cent). The lime nitrogen gave poor results on sand and sandy clay loams, 

 but good results on better kinds of soils, except in the case of beets. 



The best results with the nitrogenous fertilizers were as a rule obtained from 

 top-dressing in the spring. With fall application there is likely to be a consid- 

 erable loss of nitrogen. Lime nitrogen, however, may be used in the fall with 

 better results than sodium nitrate or ammonium sulphate. Sodium nitrate did 

 not reduce the sugar content of beets when applied before June 20. 



In comparative tests of phonolite and potash salts on potatoes and sugar beets 

 the phonolite had little or no effect, while potash salts increased the yields 

 materially. The phonolite, however, did not decrease the starch content of the 

 potatoes, as was the case with the potash salts, but, on the other hand, slightly 

 increased it. 



Tests of sodium nitrate on beets grown for seed gave inconclusive results. 



The loss of nitrogen in stable manure, B. Niklewski {FilliUng's Laiidiv. 

 Ztff., 59 (1910), A^o. 21, pp. 752-760).— The author refers to the difference of 

 opinion among investigators as to whether nitrification goes on in stable manure, 



