SOIL FERTILITY 137 



Many other investigators (80, 109) have indicated that the quality of 

 peanuts is influenced by calcium to a greater extent than is the quantity 

 of fruit. A deficiency of calcium in soils is usually manifested by a large 

 number of "pops" or unfilled pods. The better quality of nuts in soils well 

 supplied with calcium is evidenced by a whiter, firmer hull, well-de- 

 veloped kernels and an increase in weight per bushel of unshelled nuts. 

 Colwell and Brady (44) have observed that in addition to decreasing the 

 number of pops, calcium also functions in increasing the number of two- 

 cavity fruit formed by the large seeded varieties. They suggested that 

 calcium exerts this favorable effect by preventing abortion of the ferti- 

 lized ovules which apparently occurs at a very early stage of fruit de- 

 velopment before shell enlargement has begun. Brady, Nelson and Reed 

 (15) have further indicated that calcium may increase the percentage of 

 pegs which make shells. 



As early as 1911 Duggar and Funchess (50) reported highly profit- 

 able increases in peanut yields from the use of lime in Alabama. In recent 

 tests on Alabama soils which were relatively low in calcium and which 

 had been subjected to intensive cultivation, Rogers (95) obtained very 

 marked responses from the use of lime. Increasing the calcium level of 

 the soil from approximately 400 pounds per acre of CaCOg, equivalent to 

 800 or 900 pounds by the application of lime, resulted in a five-fold in- 

 crease in yield of Spanish peanuts. Rogers reported that on soils low in 

 calcium, additions of lime up to 3,000 pounds gave marked increases in 

 yield of both Spanish and runner-type peanuts. 



The results of a 10-year experiment conducted on a Tifton sandy loam 

 by the Georgia Coastal Plain Experiment Station (13) showed that lime 

 applied at the rate of 500 and 1,000 pounds per acre was of little value 

 for peanuts. It was reported that the test "followed a general rotation in 

 which other crops were. fairly well fertilized." However, there is no indi- 

 cation of the calcium level of the unlimed soil. 



In field experiments conducted in Uganda, East Africa, peanuts have 

 shown no response in yields to amendments of lime (60). Workers in 

 Senegal have reported a 35-percent increase in peanut yields from appli- 

 cations of 3 tons of lime per acre (60). 



In a test of some 13 different varieties and strains of peanuts by 

 McClelland (68), in Arkansas, increases of as much as 2,000 pounds of 

 nuts and 3 tons of hay per acre were obtained with certain varieties from 

 the application of 1,056 pounds of crushed limestone. The average in- 

 crease in yield from lime with all the varieties was 890 pounds of nuts 

 and 1.03 tons of hay. 



