720 



IOWA DEPARTMENT OP AGRICULTURE 



per acre, and the acid phosphate at the rate of 300 to 400 pounds per 

 acre. These applications are made but once in a four year rotation. 



4. The soil treatment recommended for plot 6 is designated as "crop 

 residues." This treatment should be understood to mean that all products 

 except the grain or seed which are sold in grain farming, shall be returned 



TiAt^ hc Hl,fha,a^ 



to the land and used as fertilizers, 

 as follows: 



The details of this procedure are 



SUGGESTIVE PLAN FOR LAYING OUT SOIL TEST EXPERIMENT PLOTS. 



A. The clover should be clipped once or twice somewhat earlier than 

 the first cutting for hay would ordinarily take place. The clipped mate- 

 rial should be left on the land to be plowed under later. 



Seed should be taken from the second crop if there is a yield which 

 will justify the expense of the harvest. There is a strong demand in 

 this state for clover seed of good quality and the prices are such as to 

 make yields of even one or two bushels per acre quite profitable. 



B. The corn stalks should be cut with a disk or stalk cutter and 

 plowed under. 



C. The threshed straw from small grain and clover should be re- 

 turned to the land. This may be done at some convenient time. Often 



