320 EXPERIMENT STATION RECORD. 



Tlie author calls attention to the fact that a marked after-effect of the nitrate 

 of soda is noticeable, even as late as two years from its application ; there is 

 an increase in the subsequent crops grown on the nitrate plats, as previously 

 called attention to by Maercker, Wagner, and Weitz ; the explanation given by 

 Wagner is that the nitrate is changed by the calcium carbonate in the soil 

 into sodium carbonate, which occludes the soil particles and increases the water- 

 retaining power of the soil, and thereby also the subsequent crops grown on the 

 land. — F. w. woLL. 



Recent contributions to our knowledge of moor land culture, H. von 

 Feilitzen (j^. Landtbr. Akad. Handl. och Tidskr., JfJf {1905), No. 6. pp. 369-' 

 381). — A general resume of recent reseai'ch work on moor soils. 



Culture trials of the Swedish Moor Culture Society at Jonkbping and 

 Flahult, II. voN Feilitzen {tivenska MosskultHvfiJr. Tidskr., 20 (1906), No. 

 3, pp. 193-219, p'l/s. 2). — Among the trials described in this report the following 

 may be mentioned : Trials with liming and applications of sand, white moss 

 or peat soil (dyjord) on moor soils; fertilizer trials with 37 per cent potash 

 salt and mineral fertilizer (groiuid feldspar) ; with different potash salts, 

 phosphates, and nitrogenous fertilizers, with lime niter, nitrate of soda for 

 pasture laud and for winter rye on sanded white-moss sdils. — f. w. woll. 



Plant culture and fertilizer trials in Northern Norway (Tromso Stift), 

 B. R. Laesen (Tidsskr. Xorske Laiidhr.. 12 (1905). No. 9. pp. 389-5.98 ) .—The 

 article gives a brief account of trials with potatoes, turnips, and other root crops, 

 and of a few fertilizer trials conducted in this northiern region. In several 

 subsequent issues of the Tidsskrift various phases of agriculture in this region 

 are further discussed by diffei'ent writers. — f. w. woll. 



Results of vegetation experiments in the years 1901-1903, D. N. Pei- 

 ANisiiNiKOv {Izv. Moscov. Sclsk. Klioz. Inst. {.±1111. Inst. A(jroii. Moscou), 11 

 (1905), No. 2-3, pp. 155-219). — The present article is a report for the sixth, 

 seventh, and eighth years of the culture experiments. The following are the 

 general conclusions of the author : 



(1) By the introduction of ammonium salts in sand cultures the conditions 

 of the assimilation of phosphoric acid are essentially changed, even the diffi- 

 cultly soluble phosphates becoming available for all the plants. This influence 

 may ordinarily be caused by nitrification, but it may also result from the physio- 

 logical acidity of such salts as ammonium sulphate. It is obvious that in the 

 nitrification of the latter two acids — nitric acid formed from the base and 

 sulphuric acid — must be neutralized. Ammonium nitrate of all the sources 

 of nitrogen appears to be most favorable for the maintaining of the nutrient 

 solutions in the neutral state ; but even this salt can not be used when the avail- 

 ability of the various phosphates is tested, since it may undergo nitrification 

 and may also become physiologically active. 



(2) Ash washed with water (to remove potassium carbonate) contains the 

 phosphoric acid in a highly assimilable form ; the development of plants pro- 

 vided only with this source of phosphoric acid is not only equal to that of 

 " normal cultures," but frequently surpasses it ; this once more proves that the 

 so-called normal cultures elaborated by Knop, Hellriegel, and others do not 

 have the ideal composition. 



(3) As in previous experiments, phosphoric acid in the form of bone meal 

 proved in sand cultures to be fairly available, the yields with bone meal being 

 in most cases not lower than 60 per cent of those obtained with soluble phos- 

 phates. If, however, calcium carbonate or ferric hydrate were added the 

 yields with bone meal were considerably lower. 



(4) The sand cultures with phosphorites of different origin seem to war- 

 rant the conclusion that the variations in the solvent power of different plants 



