12 



cows under such conditions that the income and outgo of all 

 the elements of the food is accounted for, the outcome of 

 which indicates that under ordinary management a cow giving 

 a larger flow of milk v/ill lose calcium, the basic element of 

 lime, more rapidly than she is able to absorb it from ordinary 

 feeding stuffs. Calcium and phosphorus are closely associated 

 in bone and in the phosphatic rocks which are employed in the 

 manufacture of fertilizers, and this work in feeding, which is 

 supported by our twenty-year experiments in the production 

 of field crops, indicates that under dairy husbandry a soil 

 may be depleted of its lime quite as rapidly and as completely 

 as of its phosphorus. 



Liming the Land. 



In planning these field experiments no provision was made 

 for the use of lime, but it very soon became apparent that 

 this thin soil — which had been under cultivation for three- 

 quarters of a century, the last third of the time under tenant 

 husbandry — was very inhospitable to clover. The seed would 

 be sown in March in the wheat, and at harvest there would be 

 a complete stand of clover plants, but they were small and 

 weak, and by the next season would have largely disappeared, 

 their place being taken by sorrel. 



In the spring of 1900 one-half the land was dressed with 

 fresh burnt lime, used at the rate of a ton to the acre, the 

 lime being spread across one end of all the plots, fertilized and 

 unfertilized alike. This treatment was continued until each of 

 the five tracts of land included in the experiment had had one 

 application, after which ground raw limestone was substituted 

 for the caustic lime and has been used since, using first 1 ton 

 of the limestone dust per acre, but later increasing the dressing 

 to 2 tons. 



The outcome of this treatment has been an average increase 

 in value of the crops of the rotation amounting to three times 

 the cost of the liming. The statement has been made that 

 corn does not need lime, but in this test the liming has pro- 

 duced an increase of 20 per cent in the corn yield on the un- 

 fertilized land and on that receiving acid phosphate only, and 

 9 to 15 per cent on that receiving a complete fertilizer or barn- 



