Physical and Chemical Properties of a Sandy Loam Soil Under Irrigated Rice-Wheat Sequence in the Indo-Gangetic Plains of South Asia

Abstract

Resource conservation technologies (RCTs) such as zero tillage (ZT), dry direct seeded rice (DSR) and crop residues as mulch are known to increase productivity and profitability of rice-wheat system (RWS) in South Asia. There are, however, few studies on assessing the effect of RCTs on physical and chemical properties of soil under RWS.A field experiment on a sandy loam soil was conducted on RWS for two years at Modipuram, India involving six treatment combinations of three tillage and crop establishment methods in rice, (i) conventional puddled transplanted rice (CT-PTR), (ii) conventional dry tillage followed by direct seeding of rice (CT-DSR), and (iii) zero tillage followed by direct seeding of rice (ZT-DSR), and two green manuring options (with and without intercropping of Sesbania aculeata, -S or +S). In the succeeding wheat, rice residue (RR) was retained in sesbania green manure treatments and it was removed from no sesbania plots. Wheat was direct sown after ZT (DSW) in all the plots. Substituting PTR/ DSW without crop residues with ZT-DSR/DSW plus residue cycling reduced electrical conductivity from 0.146 dS m -1