SOIL FERTILITY 131 



tors (96) have indicated that nitrogen may stimulate vegetative growth; 

 however, the increased growth is often of little benefit because of the cor- 

 responding reduction in the shelling percentage of nuts. From our present 

 knowledge of peanut nutrition it appears possible that the poor quality of 

 nuts might have been due in many cases to a deficiency of calcium. Cer- 

 tainly the need for calcium and other nutrients would increase as the 

 vegetative growth was stimulated, and little beneficial effect from nitro- 

 gen could be expected if some other nutrient were limiting. 



In view of the conflicting evidence in the literature, it is not possible 

 to reach a satisfactory conclusion relative to the use of nitrogenous 

 fertilizers with peanuts. However, there are sufficient data to suggest the 

 possibility of obtaining profitable responses from nitrogen when adequate 

 supplies of other nutrients are present. Surely this problem warrants 

 further investigation. 



Phosphorus 



There is considerable disagreement in the literature regarding the 

 value of phosphorus in peanut fertilizers. Harper (56) and Pate (85) 

 have indicated that phosphorus stimulates the setting of fruit and de- 

 creases the number of unfilled pods. Other workers (89, 108) have sug- 

 gested that phosphorus may hasten the maturity of peanuts. While there 

 is no question regarding the plant's need for phosphorus, table 1 shows 

 that a relatively small amount of this element is absorbed by the peanut 

 plant and suggests that little may be gained from large applications of 

 phosphatic fertilizers except, perhaps, on soils extremely low in avail- 

 able phosphorus. 



Some of the earlier work in the United States and in several foreign 

 countries indicates that a greater yield response might be obtained from 

 phosphorus than from either nitrogen or potash. Batten (30) in 1922 re- 

 ported that phosphorus gave better results than any other element in 

 peanut fertilizers and recommended the use of 300 to 500 pounds per 

 acre of superphosphate. On some of the Black Belt soils of Alabama, 

 peanuts were found to be more responsive to phosphorus than to any 

 other element (3). As the result of experiments conducted in Mississippi, 

 Ferris (52) in 1922 concluded that "acid phosphate" gave the cheapest 

 increase in the production of peanuts. 



Kerle (62), in New South Wales, indicated that superphosphate had 

 proven to be the most beneficial fertilizer for peanuts in that country. 

 Moses and Sellschop (79), in South Africa, reported profitable increases 

 in peanut yields from the use of 300 pounds of superphosphate. Krauss 



