Sulphur Fractions in Acid Soil Continuously Fertilized with Chemical Fertilizers and Amendments under Maize-Wheat System

Abstract

A long-term fertilizer experiment on maize-wheat cropping system was initiated in 1972-1973 on a TypicHapludalf at Research Farm of Palampur which comprised of ten treatments up to 1980-1981. The eleventhtreatment, consisting of 100% NPK(-S) was introduced in kharif 1981. After twenty-six years of continuouscropping (kharif 1981 to rabi 2007-2008), the effect of different chemical fertilizers and amendments withor without sulphur (S) application was studied on different forms of S. Continuous application of chemicalfertilizers and amendments improved all the S fractions in soil except where S was not applied. Integrateduse of balanced dose of chemical fertilizer with farmyard manure (FYM) or lime sustained higher yields ofmaize in comparison to inorganic fertilizer alone. Accordingly, S uptake was also higher when FYM orlime was applied in conjunction with 100% NPK. Continuous application of urea (100% N) alone resultedin no yield. Significant positive relationship amongst the different forms of S in soil (0-15 cm) indicatedthe existence of equilibrium among themselves. All the S fractions exhibited significant positive relationshipwith yield and S uptake by maize.