Micronutrients accumulation under pearl millet-wheat cropping system in response of salinity levels amended with sewage sludge

Abstract

Aim: The present study was undertaken to evaluate the effect of sewage sludge and saline water irrigation on micronutrients concentration in pearl millet- wheat cropping system. Methodology: The trial was conducted during 2017-2019 at Soil Research Farm, CCS Haryana Agricultural University, Haryana in a factorial random block design with three replications. There were three salinity levels of irrigation water, i.e., canal water (0.35 dS m-1), 8 and 10 dS m-1 EC of saline water; and five fertilization levels, i.e., control (no fertilizer), sewage sludge(5 t ha-1), SS (5 t ha-1) + 50% RDF, SS (5 t ha-1) + 75% RDF and 100 % RDF. However, sewage sludge was applied in Rabi seasons only. Results: Based on pooled analysis of two years, micronutrients (Fe, Mn and Cu) concentration in grain and stover/straw of pearl millet and wheat crops significantly reduced on application of saline water irrigation (ECiw 8 and 10 dS m-1) whereas, Zn concentration was non significantly affected with salinity levels. However, highest concentration of Fe, Mn and Cu was recorded with canal water irrigation. There was a significant increase in micronutrients (Fe, Mn and Cu) concentration in both crops with sewage sludge application in comparison of RDF and control treatments but in case of zinc treatment SS (5 t ha-1) + 75% RDF and 100% RDF were at par with each other. Among treatments, significantly higher concentration of micronutrients was recorded with SS (5 t ha-1) + 75% RDF treatment being at par with SS (5 t ha-1) + 50% RDF. Interpretation: Salinity affects micronutrient availability adversely. However, zinc content was not affected significantly. In such case, sewage sludge application may prove a feasible option that serves as a supplement of nutrients as well as sorting out the problem of dumping waste.