Combined effect of reduced dose of gypsum and salt tolerant varieties of rice and wheat on rice -wheat cropping system in sodic soils

Abstract

A field experiment was conducted at Lucknow in Uttar Pradesh during 2001-2002 to 2003-04 on a fine loamy, mixed, hyperthermic, sodic soil having high pH, low electrical conductivity, high exchangeable sodium percentage and very low water permeability to find out the combined effect of reduced dose gypsum and salt tolerant varieties of rice (Oryza sativa L.) and wheat (Triticum aestivum L. emend. Fiori & Paol.) on productivity of rice – wheat cropping system in sodic soil. This study revealed that application of gypsum @ 25% gypsum requirement (G.R.) and growing of salt tolerant varieties of rice (CSR 13) and wheat (KRL19) significantly increased the yield attributes and yields of these crops in the system over control treatment as well as 15% G.R. So much so it was at par with 50% G.R. with non salt tolerant varieties. The magnitude of combined effect of reduced dose of gypsum and salt tolerant varieties was reflected in terms 17 and 8.2% increase in grain yield over their counterpart varieties. Significant interaction between gypsum and salt tolerant varieties on grain yield indicated that gypsum @ 25%G.R. with sodicity tolerant varieties in rice-wheat cropping system could save about 43% of the total initial expenditure for the reclamation of sodic soils over the recommended dose of gypsum (50% G.R.) with traditional sensitive varieties. Thus, for low cost effective technology, using salt tolerant varieties of rice (CSR 13) and wheat (KRL 19) in conjunction with reduced dose of gypsum (25% G.R.) proved highly and sustainable technology for resource scarce situations in sodic soils.