Studies on Availability, Response and Critical Limit of Sulphur to Groundnut in Alfisols

Alfisols where groundnut is grown extensively in Chittoor district of Andhra Pradesh were studied for their sulphur status. The total S content of the soils ranged from 168 to 513 ppm. The total, inorganic and organic fractions of S had significant correlation with the content of soil organic carbon. The studies under green-house conditions revealed that as much as 70% of the soils significantly responded to S fertilisation. The soil critical limits were found to be 11 ppm and 25 ppm of S with 0.15% CaCl₂ and 1% NaCl extractants, respectively. Whereas the critical level of Sin groundnut plant was found to be 0.25%. The implications of the results was discussed.