SOILS FEKTILIZEES. 213 



stiflf, almost impervious, chocolate brown to grayish browu clay faintly mottled 

 with red and from 6 to 10 in. in thickness. The lower layer is a silty clay, gray 

 in color, mottled with yellow and brown. . . . 



" The chemical analyses of the soil from this area show it to have a compara- 

 tively large supply of potassium and a fair supply of phosphorus. It is some- 

 what low in nitrogen and in vegetable or organic material. . . . These analyses 

 also show that the soil is acid. . . . Another characteristic of the soil in ques- 

 tion is the presence of a heavy clay layer in the subsoil which . . . interferes 

 with drainage and air supply." 



The experiments were made ou three fields in four series of five, nine, and 

 eight s-acre p!ats. The fertilizer treatments included the use of green manures, 

 bone meal, rock phosphate, muriate of potash, ground limestone, and barnyard 

 manure. The experiments indicate that when quick profits are necessary 

 readily available forms of phosphorus would best be added to the soil. 



" The important considerations in handling soils of this type are the adoption 

 of a good crop rotation; the application of 2 or 3 tons of ground limestone, 

 thoroughly worked into the soil, and followed by additional applications of 1 

 ton evei"y six years ; the use of all the manure possible to secure at a cost not 

 exceeding $1.50 per ton, including hauling and spreading it on the field — this 

 to be applied chiefly before the corn crop ; and, finally, the application of 150 

 to 200 lbs. of steamed bone meal or acid phosphate to be drilled in with the 

 wheat where this crop is used in the rotation." 



Soil experiments on the dark prairies of central and northeast Missouri, 

 M. F. Miller, C. B. Hutchison, and R. R. Hudelson iilissoiiri Sta. Bnl. 127 

 (1915), pp. 355-384, fiffS- 7). — The soil on which these experiments were con- 

 ducted is the Grundy silt loam, which occupies the undulating to gently roll- 

 ing prairie of northeast and north-central Missouri. It " consists of a very dark 

 brown to nearly black silt loam, 9 to 12 in. deep, gradually becoming lighter 

 in color with increasing depth. The subsoil consists of a dark drab, plastic 

 clay loam changing at 30 in. to a yellow gray silty clay mottled with brown." 



The experiments were conducted on three fields, in three, four, and one series 

 of five, eight, and five plats, respectively. The fertilizer treatment on the first 

 field included the use of green manures, ground limestone, bone meal, and 

 muriate of potash, and on the second field rock phosphate and barnyard manure 

 were used in addition. The rotation on the second field was one of corn, oats, 

 wheat, and clover, substituting cowpeas for the clover in case of clover failure. 

 The experiments on the third field were planned chiefiy as a test of the effect 

 of catch and cover crops on soil fertility, and included also a test of bone meal 

 and rock phosphate in combination with pasturing. 



The results of the experiments indicate that this soil is deficient in both 

 nitrogen and organic matter and that the supplies of phosphorus and potassium, 

 while considerably above those of an average soil, are largely in unavailable 

 forms. The soil is also acid. 



Some profit was derived from all the treatments except cowpeas drilled in 

 the corn at the last cultivation for a green-manure -crop. " The use of manure 

 and lime have both brought consistent and valuable net returns, while good 

 average net returns have also been secured from the use of phosphorus, and fair 

 returns from the use of potassium." 



Specific recommendations for the management of this soil to increase its 

 productiveness are given. 



Soil experiments on the rolling' glacial land of north Missouri, M. F. Miller, 

 C. B. Hutchison, and R. R. Hudelson {Missouri Sta. Bui. 128 {1915), pp. 

 385-401, figs, 4)' — The soil on which these experiments, begun in 1907, were con- 



