SOIL FERTILITY 



145 



Effects of Soil Properties on Calcium Requirements 



Several studies have indicated that the response of peanuts to calcium 

 is governed to a large extent by certain soil properties. Attempts have 

 been made to correlate the level of exchangeable calcium in soils with 

 response to lime additions. Rogers (95) found that the response of pea- 

 nuts to lime was related to the exchangeable calcium level of the soil and 



10 



DATA FROM COLWCLL ANO 



BRADY 



DATA FROM ROCERS 



CHECK YIELDS AS PER CENT OF 

 THOSE OBTAIMEO WITH CALCIUM 



X 



-L 



J_ 



X 



d. 



J L 



Q2 0.4 06 0.8 1.0 1.2 1.4 1.6 1.8 2.0 2.2 



M.E. Ca per 100 GRAMS OF SOIL 



Figure 6. — The relationship between lime response and the level of ex- 

 changeable calcium in the soil. Work by Col well and Brady (45) was 

 conducted on Norfolk soils in North Carolina while data by Rogers 

 (95) was obtained from work with Norfolk soils in Alabama. 



indicated that the critical level of exchangeable calcium for peanuts on 

 Norfolk soils in Alabama was between 0.6 and 0.8 m.e. per 100 grams of 

 soil. Colwell and Brady (45) also observed a correlation between the 

 exchangeable calcium level of soils in North Carolina and the response 

 of peanuts to additions of lime. The relationships between the lime re- 

 sponse and exchangeable calcium level as reported by Rogers and by 

 Colwell and Brady are shown in figure 6. It is interesting to note the dif- 

 ferences in the data obtained by investigators in the two States. Little re- 

 sponse resulted from liming soils in Alabama which contained more than 



