SOILS FERTILIZERS. 21 



The alkaline soils in Egypt and their treatment, V. M. Mossfiei {Bui. Inst. 

 Egyptien, 5. ser., 5 {1911), No. 1, pp. 5S-79). — An examination of unproductive 

 soils in different parts of Egypt showed the widespread existence of injurious 

 alkali, consisting principally of carbonate, bicarbonate, chlorid, and sulphate 

 of sodium. Of these the carbonate is considered the most injurious to both 

 plant growth and the physical condition of the soil, it being found without ex- 

 ception that unproductive, compact, impervious soils difficult to drain contained 

 sodium carbonate in large or small amounts, and also bicarbonate in amounts 

 usually from two to three times those of the carbonate. A strong soil contain- 

 ing 0.08 per ceut of sodium carbonate is said to be rendered absolutely useless. 

 The bicarbonate of sodium, however, is considered to be less harmful than the 

 chlorid. 



It was demonstrated that gypsum in proper amounts, in addition to overcom- 

 ing the toxic effect of sodium carbonate, corrected its effect on the porosity and 

 permeability of the soil. It is concluded in general that the gypsum should be 

 applied in double the amount theoretically required and in two or three treat- 

 ments well distributed and well mixed with the top layer of soil. A copious 

 irrigation after a treatment is said to aid the chemical reaction between the 

 gypsum and the sodium carbonate, and good drainage is considered indis- 

 pensable. 



Tests of the solubility of the local gypsums relative to fineness are recorded, 

 the solvents used being water, 1 per cent hydrochloric acid, and one-hundredth 

 normal hydrochloric acid. It is concluded that a degree of fineness allowing it 

 to pass a sieve having 34 meshes per linear centimeter is sufficient. 



The movements of soil water in an Eg-yptian cotton field, W. L. Balls 

 {Jour. Agr. Sci. [England], 5 {1913), No. 4, pp. 469-^82, figs. 7; abs. in Internat. 

 Inst. Agr. [Romel, Mo. Bui. Agr. Intel, and Plant Diseases, 4 {1918), No. 12, 

 pp. 184-5-1847). — This paper describes and discusses a series of soil water 

 determinations made in a field of cotton at Giza, in Egypt. These were made 

 every three or four days alternately and at 20 cm. intervals down to 160 cm. 

 The soil is alluvial the first 30 cm., the next 60 cm. stiff clay, the next 110 cm. 

 loam to sandy loam, and below 200 cm. stiff clay. The rate of evaporation from 

 this field of cotton plants averaged about 20 tons per acre of water a day from 

 May to October. 



The chief conclusions drawn from these determinations are as follows: (1) 

 The depth of root may be roughly traced by its drying effect on the soil, which 

 combined with a change in surface climate causes a reversal of the humidity 

 gradient so that deep soil is drier than surface soil in September. (2) Appli- 

 cation of irrigation water to the surface is evidence to an indefinite depth and 

 absence of such evidence is due to imperfection in the method of observation. 



(3) Determination of soil water content in an Egyptian cotton field by random 

 sampling is almost worthless unless due regard is paid to the seasonal variation. 



(4) The water of the water table when within 2 meters of the surface may be 

 utilized by the crop. (5) A rise of the water table is analogous to surface 

 Irrigation and there is some indication of a direct hydraulic thrust in both 

 cases. 



The water balance and losses of plant food in fallow loam and sandy soils, 

 1905-1912, C. VON Seelhorst et al. (In Festschrift zum siebz^igsten Gchurt- 

 stagc von Jacob Esser. Berlin, 1913, pp. 1-27; Jour. Landw., 61 {1913), No. S, 

 pp. 189-215). — The investigations summarized in this article were made in 

 vegetation tanks of IJ cubic meters content. 



The results show that evaporation was larger from the loam than from the 

 sandy soil, each being repeatedly cultivated each summer during the period 



