136 HATCH EXPERIMENT STATION. [Jan. 



very little good. Dissolved bone-black alone gives a crop 

 less than the average of the nothing })lots. The combination 

 of nitrate of soda and dissolved bone-black gives a very 

 inferior crop, but wherever potash is used the crop is good. 

 Particular attention is called, further, to the fact that the 

 continuous use of lime alone is not beneficial ; on the con- 

 trary, the yield on the plot where lime has been continuously 

 used is the poorest in the field. Plaster used alone and 

 continuously gives a slightly better crop, but not much in 

 excess of the nothing plots. It may perhaps be urged that 

 the soil of this field must be of very exceptional character ; 

 that, otherwise, the so long-continued use of one fertilizer 

 element could not produce the results obtained. To a. cer- 

 tain extent this criticism may be justified, and I do not call, 

 particular attention to the marked efiect of the potash for the 

 purpose of urging upon our farmers exclusive dependence 

 upon this fertilizer, but to make more emphatic the point 

 that our farmers in general should insist that fertilizers de- 

 signed for use for the corn crop should be richer in potash 

 than is usually the case. The results obtained in previous 

 years on this field indicate not so much that this soil is defi- 

 cient in potash, — for some crops, such as grass, for example, 

 do well on the plots to which no potash has been applied 

 since the beginning of the experiment, — as that the corn 

 crop depends in a marked degree upon a liberal supply of 

 readily available potash. 



B. — Soil Test with Mixed Grass and Clover (JVorfh Acre). 

 The acre used in the north soil test has been kept in this 

 experiment fifteen years, beginning in 1890. The fertilizers 

 have been used in the same combinations and in general in 

 the same amounts on the several plots as in the south soil 

 test, except that during the years when onions have been 

 grown the fertilizers have been used in double the usual 

 quantities. Each fertilizer or combination of fertilizers has 

 been used continuously upon the same plot. In this experi- 

 ment the plots were divided transversely in 1899, and lime 

 was applied at the rate of 1 ton to the acre to one-half of 

 each plot. The lime was applied after plowing, and har- 



