J22 EXPERIMENT STATION EECOKD. [Vol.35 



experimental farms in Kentucljy, eacli of whicli is typical of a more or less 

 extensive area of farming lands, on the fertilizer and manurial requirements 

 of the soil and on crop rotations and adaptations. 



Bumside Field, Pulaski County.— On a limestone soil, deficient in organic 

 matter and nitrogen, growing corn, oats, clover, soy beans, and wheat, it was 

 found " that no improvement was made in the absence of phosphates, and there 

 was very little increase in yields due to potash. ... On this soil acid phos- 

 phate is more effective, dollar for dollar, than rock phosphate. . . . The best 

 yield of clover was made on the rock phosphate plat." 



London Field, Laurel County.— On a moderately acid silt loam soil, with 

 minimum potash content, growing a 4-year rotation of corn, cowpeas or soy 

 beans, wheat, and clover, it was found that limestone and acid phosphate were 

 highly beneficial, the most profitable treatment being a combination of the two. 

 Potash used alone and with limestone and acid phosphate did not increase 

 the yields, but gave profitable results when used only with acid phosphate. 

 The results are taken to justify "the recommendation of the use of potash 

 on the soils of this region when lime can not be used, especially on the more 

 sandy soils." 



Lexington Field, Fayette Cotmfy.— Experiments on a slightly acid soil typical 

 of the Trenton limestone region on which was practiced a rotation of corn, soy 

 beans, wheat, and clover showed no consistent or decided effect from any of 

 the fertilizing constituents (acid phosphate, potassium sulphate, or limestone) 

 applied. It is considered safe to conclude that " the use of phosphates and 

 potash is not necessary on the well-drained, highly phosphatic soils of the 

 Trenton limestone formation when organic matter is maintained in quantities 

 to furnish the necessary nitrogen for good crop yields." 



Berea Field, Madison County. — Experiments on a strongly acid silt loam 

 soil supporting a rotation of corn, soy beans, wheat, and clover, with cowpeas 

 as a catch crop, led to the conclusion that " limestone and phosphates have 

 shown decided results. Limestone is probably the first requirement of this 

 soil and phosphate next. The best results were obtained by using both to- 

 gether." 



Greenville Field, Muhlenberg County. — Experiments on a moderately acid 

 silt loam soil, typical of the uplands of the Western Coal Field, on which two 

 rotations were practiced, showed, with the rotation of corn, soy beans, wheat, 

 and clover, with cowpeas as a catch crop and rye as a winter cover crop, 

 " the need for the combination of limestone and phosphates in the Improve- 

 ment of these soils. . . . Potash has given good increases in some cases. . . . 

 Wherever phosphates were used good yields of clover were obtained, whether 

 any other material was used or not." With the tobacco, potatoes, and clover 

 rotation no material increase was observed with any treatment which omitted 

 phosphorus. Potash gave only slight increases. Limestone did not injure the 

 potatoes and nitrogen was profitably used on tobacco and potatoes. 



Russelville Field, Logan County. — Experiments with a slightly acid silt loam 

 soil typical of the St. Louis limestone formation and supporting a rotation 

 of corn, soy beans, wheat, clover, and timothy gave results which are taken 

 to justify the conclusion "that limestone and phosphates may be used with 

 profit on such soils, especially when used together. The effect of phosphates 

 Is especially apparent on wheat and clover. The effect of limestone is es- 

 pecially noticeable on the corn crop of 1915, as is also the case on the clover 

 crop sown in 1915. Potash has produced considerable increases on the 1915 

 corn crop In some cases." 



