Sulphur fractionation studies in soils of long term fertilizer experiment under finger millet – Maize cropping sequence

The long term field experiment has been in progress since 1986 at GKVK, Bengaluru with finger millet – hybrid maize cropping sequence. Eleven treatments were replicated four times in RCBD. The archived soil samples (1986 – 2016) from this experiment were collected at five years interval and studied for different fractions of sulphur. The fractions of sulphur were in the order of organic>residual>inorganic>water soluble> available forms. All fractions of S showed an increasing trend over 30 years of cropping cycles in all the treatments. However, the treatments which did not receive any source of sulphur decreased initially (1991) in all S fractions and then increased gradually over the years and maintained slightly higher over the initial.