POTASH IN MASSACHUSETTS SOILS 5 



at which it was settled that the fertilizers to be employed should consist of 160 

 pounds nitrate of soda (16 percent nitrogen), 320 pounds dissolved boneblack 

 (16 percent soluble phosphoric acid), and 160 pounds muriate of potash (50 percent 

 actual potash) per acre. When all three substances were applied together, the 

 soil would receive per acre 25.6 pounds nitrogen, valued at $4.35; 51.2 pounds 

 soluble phosphoric acid, valued at $4.10; and 80 pounds potash, valued at $3.60. 

 The outstanding features of this combination of fertilizer chemicals were the 

 simple units of 1 and 2 pounds per square rod, and the nearly equal distribution of 

 cost between the three kinds of fertilizers used. 



The plan of cooperative fertilizer experiments was adopted by this station 

 and was executed by Dr. Wra. P. Brooks. Cooperation of farmers was secured in 

 thirteen different towns, distributed from Cape Cod to the Berkshire Hills. 

 Most of the experiments were conducted in 1889, 1890, and 1891; three were 

 continued until the seventh annual crop was secured. Nearly all the fields selected 

 for the experiment were fairly level and free from stones, and had been several 

 years in grass, either as hayfield or pasture, without manure or fertilizer of any 

 kind. 



All the experiments used corn for the first crop. On some farms, new fields 

 were used in the succeeding years, but in most cases the same fields served year 

 after year. Potatoes or oats were used for succeeding crops on a few farms. 

 Most of the experiments showed that the fields required all three forms of fertilizer 

 for the highest yields. One hill farm in Shelburne did not require potash, and one 

 near the river in Montague needed only nitrogen at that time. A comparison 

 of localities and description of soils with the soil surveys shows that these co- 

 operative experiments were almost always on the soils of the plain and terrace 

 group. The Shelburne soil was in the upland group, and the Montague soil may 

 have belonged to the alluvial or river-bottom group. All fertilizer experiments 

 at this experiment station have been on soils of the plain and terrace group. 



The results of these numerous fertilizer experiments with a variety of crops, 

 together with the relatively low cost of potash fertilizers, led to recommendations 

 for liberal applications of potash to most crops on all soils in this State. 



At the New Hampshire Agricultural Experiment Station, however, fertilizer 

 experiments on its soils and observation of farm practices in its vicinity showed 

 that the liberal use of potash was unnecessary on such soils. In general, they were 

 a clay loam overlying a dense un weathered clay, or granite rock. Angular boulders 

 of granite were scattered through the soil and showed that the material had been 

 deposited from the melting glaciers as they approached the ocean, and not from 

 streams of water. In fertilizer experiments with grass and clover, potash gave 

 no increases in yields, while nitrogen alone produced marked gains. Analyses of 

 the crops showed that the percentages of potash in the crops were fully main- 

 tained by the soil. Such results indicated that liberal applications of potash might 

 be uneconomical because a part of the crop's needs could be obtained from the 

 soil without its impoverishment. 



Review of Soil Analyses 



In the Annual Report of the Massachusetts Agricultural Experiment Station 

 issued in 1911, there are descriptions and chemical analyses of thirteen soils which 

 represent distinctive geological formations in different sections of the State 

 (pp. 339-341). 



In 1914 Director Wra, P. Brooks had these typical localities again sampled, 

 together with some additional areas. The purpose of this later study was to 



