9 



phate, the gain attributable to the lime is 77 and 75 per cent. It is 

 noteworthy in this connection that the smaller amount of lime, i. e., 

 1,000 pounds per acre, has in each instance given slightly the larger 

 increase. This seems to show that while the lime is very beneficial, 

 the requirements of this soil are fully met by an application of 1,000 

 pounds per acre. Another striking thing in regard to the lime is that 

 it has produced nearly twice as much gain when used with a complete 

 fertilizer as when used alone, and, since commercial fertilizers are 

 extensively used, this makes the application of lime all the more 

 important. A complete commercial fertilizer as above used, costing a 

 little more than $10 per acre, gave only a moderate gain of 30 per cent, 

 and the addition of 1,000 pounds of lime, worth not more than $1.50, 

 increased the percentage gain to 107. The financial side of this is too 

 obvious to need discussion. 



Barnyard manure has given a considerable increase, but from the 

 economical standpoint is not equal to cowpeas and lime, and, further- 

 more, its use is restricted for want of supply. 



RESIDUAL EFFECT OF FERTILIZING MATERIALS. 



In order to ascertain what the residual effects of the treatments might 

 be, a number of the baskets used in the experiments detailed in the 

 above table were replanted without further addition of fertilizing 

 materials. The following table gives the original treatments, and the 

 lines represent graphically the comparative growth for both the first and 

 second crops: 



Com par at ire growth of wheat on Portsmouth sandy loam, for various treatments- 

 first and second crops. 



First crop ^ ^ ^_ Second crop , 



It should be noted in the above table that a fresh untreated sample 

 of soil was introduced in order to ascertain if the conditions during the 

 growth of the second crop compared favorably with those which pre- 

 vailed in case of the first. The untreated fresh soil gave a very slightly 



