130 EXPERIMENT STATION RECORD. 



decreased humus supply and a consequent decrease in productiveness. In the 

 sections whei-e wheat has been the most important money crop, its continued 

 culture without the proper use of commercial fertilizer, which in many cases is 

 depended upon too largely for securing a crop, has thus caused a much greater 

 depletion of humus than would otherwise be found practicable." 



The results of chemical analyses of 26 samples show a striking deficiency in 

 nitrogen and usually in phosphorus. 



The methods of soil improvement recommended are, therefore, based upon the 

 use of fertilizers, especially phosphatic fertilizers, in connection with systems of 

 live stock production, crop rotation, and legume growing, which will build up 

 the humus and nitrogen of the soil and supply the deficiencies of phosphoric 

 acid. 



Alkali soils. — Irrigation waters, G. S. Fraps {Texas Sta. Bui. ISO, pp. 

 5-28). — This bulletin discusses the nature, origin, and effect of alkali on plants, 

 the prevention of alkali and the utilization of alkali soils, the occurrence of 

 alkali in Texas, and the quality of irrigation waters of the State with reference 

 to the accumulation of alkali in the soil. The examination of a large number 

 of samples of soil showed that alkali occurs in almost all sections of the State, 

 even in the relatively humid eastern portion. The alkali soils, however, occur, 

 as a rule, in comparatively small areas. 



A bibliography is appended. 



Soil moisture studies at the North. Platte substation, W. W. Burr ( Nebraska 

 Sta. Rpt. 1909, pp. 62-99, charts 2). — Tabular summaries are given of observa- 

 tions on moisture in soils down to a depth of 6 ft. under different methods of 

 cropping in the experiments which were begun at this substation in 1907 in 

 cooperation with the Bureau of Plant Industry of this Department. Mechanical 

 analyses of the soil are also reported and the method of sampling used is de- 

 scribed. The seasonal rainfall at North Platte for 35 years, 1875 to 1909, is 

 given in tables and diagrams. 



The movement of water in the soil and the air in the soil, N. S. Nesterov 

 (Diicvn. XII. H"iczcla Ross. Est.-Isp. i Vrach., No. 8, p. 337; ahs. in Zhur. 

 Opuitn. Agron. (Riiss. Jour. Expt. Landw.), 11 (1910), No. 1, pp. 86, 87). — 

 The author maintains that the movement, in the soil, of the water which is not 

 subject to the action of the capillary forces but is transported by the force of 

 gravity, depends essentially on the pressure of the air in the soil. This factor 

 determines both the extent of the percolation of the precipitation into the soil 

 and the velocity of the movement of the underground waters. This theory of 

 the author is based upon data of many years' observations under a variety of 

 natural hydrological conditions, and on results obtained from experiments in 

 introducing water into the soil by means of a special form of apparatus. 



The air in the soil greatly impedes the percolation of the water and brings 

 about two A'ery unfavorable conditions, viz, the run-off of most of the water 

 and the absorption of a small amount by the soil. Conditions may be improved 

 by air drainage of the soil and the boring of holes through it. The investiga- 

 tion of the pressure of the air in the soils is, in the opinion of the author, one 

 of the urgent problems of agriculture. 



Determination of the absorbed bases in the soil, D. N. Prianishnikov 

 (Dnevrt. XII. 8"iezda Ross. Est.-Isp. i Vrach., No. 7, p. 301; ahs. in Zhur. Opuitn. 

 Agron. (Russ. Jour. Expt. Landw.), 11 {1910), No. 1, pp. 147, 148). — It is often 

 assumed that only the zeolitic substances in soils are available as plant food, 

 but there is very little positive data supporting such a view. On the other 

 hand, pot experiments at the Moscow Agricultural Institute begun in 1901 

 show, in agreement with laboratory experiments by K. D. Glinka, that anhydrous 



