SOILS FEETILIZERS. 215 



The eight years' experiments show that " the most profitable system of soil 

 management tried is one using green manure catch crops to supply organic 

 matter and nitrogen, hone meal to supply phosphorus, and chlorid (muriate) 

 of potash to supply available potassium. Lime has not proved profitable as 

 an average of the entire period, though it was profitable during the first two 

 or three years." The results of seven years' tile draining experiments show 

 that " the increased yields, . . . with tile laid at intervals of 6 rods, have paid 

 the cost and a fair rate of interest on the investment." The results of blasting 

 experiments on this soil showed that an average annual increase in crops 

 valued at $1.60 per acre was obtained, while the cost of the blasting was $12 

 to $15 per acre. 



Specific recommendations for the management of this soil to increase its 

 productiveness are given. 



[Soil experiment fields] (Missouri Sta. Bui. 131 (1915), pp. 492, 493, fig. 1).— 

 For several years the station has maintained experimental fields in different 

 parts of the State. Twelve of these are knawn as soil fields, being devoted 

 primarily to the study of soil problems. The results obtained on these fields 

 have been reported in detail from time to time in bulletins of the station (see 

 above). The more important of these results are briefly summarized as follows : 



"(1) Phosphorus is the element which can be applied with the largest net 

 return on Missouri soils. (2) The best form of phosphate to apply under aver- 

 age conditions is one of the available phosphates, such as bone meal or acid 

 phosphate. Rock phosphate brings slower returns and is adapted largely to the 

 man who has time to wait for results and capital to invest. (3) Lime bi-ings a 

 small but rather consistent return on practically all the fields under experiment. 

 These fields, however, are those more likely to need lime than a great many soils 

 in Missouri. (4) Barnyard manure is worth about $1.65 per ton as measured 

 by crop increase and as an average of all experiments conducted." 



Sketch of the geology and soils of the Cahuilla Basin, E. E. Free ( Carnegie 

 Inst. Washington Pub. 193 (1914), pp. 21-33, pis. S).— The author deals with 

 the descriptive and historical geology of the basin and discusses the origin and 

 character of the soils. 



The two soil types represented in the basin are the desert soils of the slopes 

 and the river alluvium soils of the Colorado Delta. The former are mainly 

 sandy and gravelly, are mineralogically very heterogenous, and are amply sup- 

 plied with useful soil-forming minerals. The alluvial soils are similarly diverse 

 and fertile, but differ in that their mineral particles are somewhat weathered and 

 are more uniform in size. Practically all of them are silts or very fine sands, their 

 chief fault, aside from the frequent presence of alkali in the silts, being too 

 great heaviness and diSiculty of working. The sandy soils are seldom alkaline. 



It is stated that the submergence of the soils by the waters of the Salton Sea 

 seems to have had little effect upon their alkali content. It is also stated that 

 no direct infiuenee of the soils upon the local distribution of vegetation was 

 discernible. 



The colloidal properties of the acid soils of Japan, T. Tadokoro (Jour. Col. 

 Agr. Toholcu Imp. Univ., 6 (1914), No. 5, pp. 111-129, figs. 2).— In continuation 

 of previous work along the same line (E. S. R., 32, p. 318), the author reports 

 experiments in which he compared the colloidal properties of neutral sand, 

 clay, and humus soils with those of acid soils as determined in the previous 

 experiments. 



In the experiments with the neutral soils it was found that the increase of 

 the volume by swelling on treatment with reagents, the adsorptive power for 

 coloring matter, and the absorption coeflScient for ammounia were greatest 



