Sulfur Sorption under Maize–Wheat Cropping System as Influenced by Long-Term Effects of Chemical Fertilizers and Amendments in an Acidic Alfisol of Western Himalaya

Abstract

Long-term effects of chemical fertilizers and amendments on sulfur (S) sorption under a maize–wheat system were investigated in a randomized block design with 11 treatments replicated three times, during winter (2007–2008) and summer (2008) seasons, in an ongoing long-term fertilizer experiment at the farm of College of Agriculture, CSK Himachal Pradesh Agricultural University, Palampur, India. Soils of the experimental site were acidic and classified taxonomically as Typic Hapludalfs. Soil samples taken from the surface (0–0.15m) after harvest of wheat (winter 2007–2008) and were analyzed for sorption behavior of S. Maximum sulfate adsorption was in 100% nitrogen (N)–phosphorus (P)–potassium (K) without S treatment and was attributed to continuous cropping without S application, leading to a deterioration of soil S fertility. Increases in the rate of long-term S fertilization caused a considerable reduction in the sulfate adsorption. Application of farmyard manure (FYM) as an amendment also reduced sulfate adsorption as compared to other inorganically fertilized plots. With the increase in the desorption of S in soil, the S concentration in soil solution increased.

Keywords:

• Adsorption
• desorption
• Freundlich and Langmuir adsorption constants
• maximum buffering capacity
• sulfur sorption