44 



MASS. EXPERIMENT STATION BULLETIN 232 



be highly variable. There are also loeal variations whieii occur in areas 

 too small to receive separate classification. Physical analysis of soil 

 samples drawn from four of these five fiekls gives the following results :- 



Physical Analysis of Soils 



The surface soil samjiles were taken down to plow depth, tho.se of the 

 subsoil to a depth of thirty inches. According to the modified scheme ^ 

 of textural classification as developed by Dr. A. B. Beaumont/ these soils 

 would all be classified as sandy loams. 



While the above soils are similar in physical characteristics, yet they 

 are subject to wide differences in moisture supply. Field G lies in a 

 hollow, is relatively poorly drained, and has a stiff subsoil of a character 

 inadequately portrayed by physical analysis. In its moisture relations 

 Field A is almost ideal, while progressively Field B and the two Soil Tests 

 are somewhat subject to drouth. 



Work on these five fields was instituted years ago — that on the Soil 

 Tests and Field G under the leadership of former director William P. 

 Brooks; that on the other fields mentioned, by the late Dr. C. A. 

 Goessmann. 



The Need for Fertilizer Potash 



Need for fertilizer potash may be considered as synonymous with plant 

 response to the application of potash fertilizers. Crops grown in the 

 Soil Tests above referred to show distinct response to such application. 

 That such response was influenced by the kind of crop being grown was 

 evident, but the number of times a given crop was grown was too small to 

 permit a safe generalization as to the relative potash-foraging ability of 

 different plants. The following table abstracted from Bulletin No. 212 

 shows the crop returns per acre from the use of potash under conditions 

 where manure was not applied: — 



The analyses were made by Mr. O. W. Kelly of the Department of Agronomy of this 

 institution. 



? .Tour. Amer. Soc. Agron. v. 18, No. 3, pp. 238-216. 



