FIELD EXPERIMENTS IN THE SOUTH 



489 



"Nitrogen, applied to the soil as dried blood in combination with phosphorus 

 and potassium, produced an increase of 1800 pounds of clover hay per acre 

 over that grown with the minerals without dried blood." 



"Clover should be grown extensively in southern Iowa for the following 

 reasons : 



" a. The soils of this section of the state are deficient in nitrogen and organic 

 matter. 



" b. These soils tend to wash because they lack humus." 



Georgia field experiments. The Georgia Agricultural Experiment 

 Station has reported a large number of fertilizer experiments, 

 especially with cotton and corn; and the " Georgia rotation " 

 has also won distinction for that station. This is a three-year 

 rotation, as follows: 



First year. Cotton. 



Second year. Corn, with cowpeas seeded at the last cultivation 

 and harvested for seed only, the vines being left on the land for 

 soil improvement. 



Third year. Winter oats, followed by a regular crop of cowpeas 

 to be harvested for hay. 



For this rotation, on worn uplands, Director Redding recom- 

 mended the following applications per acre (Georgia Bulletin 

 72, 1906): 



The fertilizer materials used are usually cotton-seed meal, acid 

 phosphate, and potassium chlorid, although some use may be made 

 of sodium nitrate, and kainit may replace the concentrated salt. 



In the main this system is designed to apply for each crop the 

 plant food which it needs, without much reference to the improve- 

 ment of the soil, although farmers are urged to make and use farm 

 manure so far as possible, and the statement is also made that 



