Sulphur status of Indian soils is going down with each passing year. Close to 70% of soil samples analyzed by the ICAR system, TSI-FAI-IFA project and other programs have been found to be either deficient or marginal in plant available sulphur.
In the early 1990s, sulphur deficiencies in Indian soils were estimated to occur in about 130 districts. More recently, soil fertility surveys by the ICAR system (analysis of 60,000 soil samples) have shown sulphur deficiencies to be a widespread problem. A soil is considered deficient in S if it tests less than 10 mg S/kg soil extractable with 0.15% CaCl2.
A = 45% districts having more than 40% soil samples deficient in S
B = 40% districts having 20-40% soil samples deficient in S
C = 15% districts having less than 20% soil samples deficient in S
Soil analysis and crop response data generated by the TSI-FAI-IFA project (1997-2006) re-enforced the findings of the ICAR system. Based on reported results, out of over 49,000 soil samples analyzed across 18 states, 46% of samples were deficient in sulphur and another 30% were medium in available sulphur which could be considered as potentially sulphur deficient. Soil sulphur deficiencies were encountered in all parts of the country. These data prove that sulphur deficiencies are a critical problem in 40-45% of districts translating into 57-64 million ha of net sown area. State-wise sulphur scenarios are available:
Several factors contribute to the growing incidence of S deficiency in India.