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available by seasons; therefore, a value of 4.2 kg/ha of S will be used 

 as an estimate of S absorbed directly by the soil during the 6-month 

 growing season. 



No values are available on the amount of S that may be absorbed 

 directly through the bahiagrass foliage. Olsen's estimate of 30% of 

 the total plant's S needs was a function of the effective leaf surface 

 of healthy cotton plants (Olsen, 1957) . Bahiagrass forms a dense mat 

 of stolons and roots that cover the soil surface. Foliage at harvest 

 rarely exceeds 60 cm in height. Much of the estimated 4.2 kg/ha of S 

 that would be absorbed by the soil might, in fact, be absorbed by the 

 plant before reaching the soil — particularly if the plant is growing 

 under S-deficient conditions. Any S0„ absorbed by the soil surface 

 during the winter months would likely be leached through the rooting 

 2one. 



The plant S that cannot be accounted for by the above values comes 

 from mineralization of organic S (total S) or from stolon-root S 

 carried over from the previous season. Nelson (1964) found an average 

 of 10 kg/ha of S was mineralized from 12 Mississippi soils during a 

 6-month period under controlled conditions. This value varied widely 

 with different soils. Mineralization is known to be affected by so 

 many variables that convenient field estimations of this value have not 

 been achieved. 



From the greenhouse experiment with subsoil S, we found that 

 approximately 15 mg of S/pot was removed in the tops of the sorghum- 

 sudangrass growing in surface soil of a Myakka fine sand during 16 

 weeks with no added S. If we assume that the roots contained about 

 0.10% S, then 6.5 mg S/pot remained in the roots for a total of 



