180 ANNUAL REPORT OF THE Off. Doc. 



out the 83-year [)eriod. This has been clone without the application 

 of any nitrogen, either in the foim of yard manure or fertilizer. The 

 nitrogen has been maintained by means of the clover which ap- 

 peared in the rotation. Nitrogen is essential. There are three ways 

 in which it may be obtained: by growing clover or some other 

 legume, by using yard manure, by buying it in commercial form. 

 These three ways are all right in their place, but is it not good busi- 

 ness to get as much nitrogen as possible by means of clover and 

 through the yard manure? Buying in commercial forms may be 

 necessary to supplement that obtained from these other sources. It 

 is a case of getting what you can without paying for it. In many 

 instances it has become difficult to get a stand of clover. There are 

 thousands of acres in Pennsylvania which are not as productive 

 as they should be because of deficiency in lime. Clover and the 

 leguminous crops require lime. At the Cornell Station some years 

 ago an experiment with lime and fertilizer was conducted. A poor 

 farm in the neighborhood was obtained. The faini was divided 

 into two parts, one of them which was limed and the other unlimed. 

 Different fertilizer treatments were then given to portions of both 

 the limed and unlimed series. The results were as follows: 



I 



Nothing, 



P, K 



P, K, N 



15 tons manure, 



1824 

 2349 

 2235 

 2091 



3852 

 4174 

 4085 

 4976 



P— Acid phosphate, 100 poun'la. 

 K — Muriate of potash, 50 pounds. 

 N — Nitrate of soda, 100 pounds 



In every instance better results were obtained where the lime 

 had been applied. Not only was there an increase in quantity but 

 the character of the grass itself was changed. While on the unlimed 

 plats the clover was replaced largely by red top and sorrel, on the 

 limed plats there was a considerable portion of blue grass. Any 

 land, which, when seeded to clover tends to produce red top and 

 sorrell, should be limed. 



Limestone, or carbonate of lime, is practically the only material 

 which can be used to sweeten the soil. When carbonate of lime is 

 burned a portion of it goes off into the air as gas and we have burned 

 lime or quick lime remaining. One hundred pounds of pure lime- 

 stone, if thoroughly burned, would produce 56 pounds of burned 

 lime. When water is applied to this burned lime it slakes. If water 

 is not applied to it, moisture is gradually absorbed from the air and 

 the same change takes place. If the 56 pounds of burned lime were 

 given just sufficient water to slake it, 6 pounds of hydrated lime 

 would result. 



