SOILS FERTILIZERS. 219 



E^Tpt. Landir.), 8 (W07), Xo. 2. pp. 129-146). — Pot and field experiments on this 

 subject were couducted at the Ivanov Experiment Station during the years 1904, 

 1905, and 190G on clayey chernozem soils with summer wheat and beets. 



In the pots all soils showed a great need of nitrogen fertilizer, while in the 

 field there was apparently little or no need of it. Two of the soils recjuired no 

 fertilizer whatever in the field, contrary to the ■ indications of the pot experi- 

 ments. The other two soils were very responsive in the field to phosphoric acid, 

 which raised the yield very materially, while in the pots they were but slightly 

 affected by this fertilizer. As to the potash, the results were similarly dis- 

 cordant. The author concludes that pot experiments are not suited to indicate 

 the requirements of soils for fertilizers. 



Experiments are reported in which oats were raised on the soil as soon as it 

 was removed from the field to the pot and on the same soil which had been 

 allowed to remain in the pot a year before the culture of oats was undertaken. 

 In the first case nitrogen fertilizer was very beneficial, but in the second without 

 effect. Analysis showed that by remaining a year in the pot the soil became 

 greatly enriched in nitrogen, the original nitrogen content of 17.8 mg. rising to 

 43.5 mg. per kilogram of dry soil. There is no doubt that the result In pot 

 experiments must depend to a great extent on the time of the year when the soil 

 samples are taken from the field. — p. fireman. 



Report of cooperative fertilizer trials, 1906, T. Bolin (K. Landthr. AJcad. 

 Hand], och Tidskr., .'i6 (1907), BihuiHj. pp. 103).— The cooperative fertilizer 

 trials conducted under the auspices of the Royal Swedish Agricultural Academy 

 were continued during the year, 108 ditferent series with about 5,870 plats hav- 

 ing been arranged for on 120 farms located in different parts of the country. 

 Ninety-eight series of trials were conducted with spring grains, 75 with roots, 

 24 with hay crops, and 1 with winter grains. The results of the trials con- 

 ducted during the year are given in detail in the report, with summaries for 

 the years 1904-1906. 



The following systems of fertilization produced the best financial results with 

 the different crops on the average for the 3-year period : For oats, both on 

 clayey and sandy soils 200 kg. of nitrate of soda and 300 kg. superphosphate 

 per hectare; on peaty soils, 300 kg. of superphosphate and 100 kg. potash salt; 

 for mangels, 100 kg. nitrate (top-dressing), 400 kg. superphosphate, and 2.50 to 

 800 kg. potash salt ; for potatoes, 200 kg. nitrate, 300 kg. superphosphate, and 

 200 kg. potash salt. For hay crops the best system of fertilization varied 

 according to whether grasses or clover made up the greater proportion of the 

 hay ; nitrate of soda produced, as a general rule, the best results for the grasses, 

 and phosphate for hay composed largely of legumes. For mixed clover and 

 timothy hay a comi)lete fertilizer consisting of 200 kg. each of nitrate and ix»t- 

 ash salt and 300 kg. of superphosphate produced the best financial returns. 

 The results obtained in the experiments show that the effect of a certiiin system 

 of fertilization during the years following that of the application is often in a 

 different direction from that indicated by the results of the first year. A 

 decided after effect was noted, especially in the case of clover from potash- 

 phosphate fertilization. 



A separate series of fertilizer trials with different nitrogenous fertilizers — 

 calcium cyanamid, lime niter, ammonium sulphate, and sodium nitrate— was 

 conducted during the year, viz, 2 trials with oats on clayey soil, 1 with potatoes 

 on sandy soil, 1 with fodder beets on clayey soil, 1 with mangels on sandy soil, 

 and 3 with hay crops on clayey and sandy soils. The results of previous experi- 

 ments with these fertilizing materials were in general corroborated in this 

 year's work, showing that the two kinds of nitrate possess corresponding fer- 



