858 EXPERIMENT STATION RECORD. 



soil iVrtility by tlie Uf^e of manures an<l fertilizers, by rotation, and by using on the 

 farm iturchaHed feedinjr stuffs, etc., rich in fertilizinjr constituents. 



On the importance of certain physical properties of soils and soil-forming 

 minerals in plant culture, W. B.vggeu {Luukj. Dhs., Albert u.^-Unir. KOnUjaherg, 

 IIHU, pp. S4, j)ls. 2). — Studies of the physical properties of soils as based upon inves- 

 tigations of the size, character, and arrangement of the soil particles in a large imm- 

 ber of soils are reported. The results of an attemjit to trace a relation Ijetween the 

 mechanical condition of tlie soil (size of soil particles) and the potash content are 

 also reported. 



The main conc-lnsions reached are as follows: (1) Apparently only the crystalline 

 sul)stances in soils remain in suspensi«m. (2) The arrangement of the mineral par- 

 ticles is determined to a large extent by their form. (3) The water capacity iA a 

 soil increases with a decrease in the size of the soil particles. It is clearly dependent 

 upon the form of mineral and the resulting arrangement of soil particles. (4) The 

 permeal^ility declines uniformly with the decrease in size of particle, but not with 

 decreasing compactness of arrangement of particles. (5) Cohesion in fine-grained 

 soils increases with the decrease in the size of the particles. The form and the 

 adhesive i)roperties of the mineral constituents have an important influence on the 

 cohesion. There is no clear distinction between sand and loam. In an agricultural 

 sense sand may be defined as a collection of soil particles of varying size resulting 

 from incomplete disintegration of amorphous or crystalline substances. Loam may 

 be defined as a collection of small soil particles derived from complete disintegration 

 of crystalline substances. (6) The mechanical properties (size of particles) of a 

 soil furnish no index of potash content. 



A revie-w of the more important fertilizer experiments on black soil, 

 W. vox Wiener {Landw. Vers. Stat.., 59 {1904), No. 5-6, x>P- 397-409, pi. i).— Experi- 

 ments on typical steppes black soil underlaid bj' loess, at the agricultural experiment 

 station and on a farm near Nowossil, Government of Tula, Russia, are reported. The 

 physical and chemical properties of the soil are described. A large number of crops, 

 including cereals, leguminous plants, root crops, fiber plants, etc., and various com- 

 binations of fertilizing materials as well as manure, were experimented with. In all 

 cases phosphoric acid was the element of plant food which gave best results. Nitro- 

 gen and potash were j)ractically without effect. Barnyard manure gave better results 

 than mineral fertilizer, the most effective form being fresh horse dung. The best 

 returns from the fertilizers and manures were obtained when their use was accom- 

 panied with deep and thorough culture. 



Factors of availability of potash and phosphoric acid in soils, G. S. Fraps 

 {Snence, n. ser., 19 {1904), No. 4S1, p. 443). — This is an abstract of a paper jiresented 

 at the St. Louis meeting of the American Association for the Advancement of Science. 

 "In the determination of plant food in soils, chemists have usually considered only 

 that part which is soluble in the common solvents. Solubility is not, however, the 

 only factor of fertility in the soil. The rate of decomposition or weathering of the 

 soil is of great importance, as is also the power of the plants to assimilate. Weather- 

 ing has received little or no attention. It is known to be of great imi)ortance with 

 nitrogenous bodies, but in regard to phosphorus and potash no data can be given. 

 Experiments show that there is a slight increase in both phosphoric acid and potash 

 when the soil is kept moist, and a great increase in potash when organic matter is 

 present. This accounts for the necessity for vegetable matter in soils. Another factor 

 is the difference in the solvent powers of plants. A soil may contain sufficient food 

 for one plant, but not enough for another. ' ' 



Reply to an address: Present status of soil investigation, F. K. Cameron 

 {Science, n. ser., 19 {1904), No. 478, pp. 343-347). — This is in reply .to criticisms of 

 Bulletin 22 of the Bureau of Soils by C. G. Hopkins and others (E."s. E., 15, p. 329). 



