16 



FOR BETTER CROPS 



and small differences may be attributed to soil variation, but the 

 marked and uniform effects of nitrogen, and of nitrogen with 

 potassium, are characteristic of such soil, and the further addition 

 of phosphorus may sometimes prove profitable. 



These results help to explain the marked effect of farm manure 

 on sandy soils, especially when used for a crop rotation which 

 includes legumes. Both the legumes and manure will furnish 

 nitrogen, and the manure is also well supplied with potassium, 

 the bedding being rich in potassium, and all potassium in the 

 feed being returned in the manure. It may be noted that on 

 very sandy lands clover does not grow well, but either cowpeas 

 or soy beans is an excellent substitute for clover, as both do well 

 on very sandy soil. 



It is exceedingly important that so far as possible all crops 

 shall be fed and the manure shall be carefully saved and re- 

 turned to such land, not only for its plant food value, but also 

 for the organic matter which is needed to improve the phj'sical 

 condition of the soil. 



Improving Worn Hill Land — In actual field experiments 

 on worn hill land on the University of Illinois soil experiment 

 field, near Vienna, 111., the following results have been obtained 

 in a three-year rotation of wheat, corn, and cowpeas. By 

 "legume" treatment is meant the growing of legume crops or 

 catch crops, as cowpeas in the corn, or after the wheat, in the 

 same season, which are turned under for the nitrogen and 

 organic matter which they add to the soil. 



Crop Yields in Soil Experiments 

 Worn Hill Land near Vienna, Illinois 



Soil Treatment Applied 



1903 I 1904 1905 

 Yields Yields Yields 



Wheat, Bushels per Acre 



None 



Legume 



Legume, limestone. ... 



Legume, limestone, phosphorus . 



Legume, limestone, phosphorus, potassium 



1 



'11 



18 

 26 

 30 



Corn, Bushels per Acre 



None 



Legume 



Legume, limestone 



Legume, limestone, phosphorus 



Legume, limestone, phosphorus, potassium. 



38 

 43 

 62 

 57 

 57 



The year 1903 was a very poor season for both corn and wheat. 

 It will be seen that limestone and legumes (cowpeas or clover) 

 have very great power to improve this class of soils. 



As yet the addition of phosphorus and potassium has not 



