A field experiment was conducted during 1991–93 involving rice-wheat rotation on an alkali water (ECw 3.2 dS mol−1 RSC 5.6 m equiv. L−1) irrigated sandy loam soil for evaluating the responses to applied farmyard manure and gypsum (to neutralize 0 to 100 percent RSC of applied water to previously grown crop). The added farmyard manure reduced soil pH, soil sodicity and increased significantly yields of both rice and wheat (8–18%). Significant benefit of added gypsum was observed only in first wheat (13%) that followed rice grown during deficit monsoon rainfall year (281 mm). The sustained yields of rice-wheat are possible with category I alkali waters (RSC > 4, DCR > 0.25) with occasional applications of gypsum and FYM in areas with an annual rainfall of at least 500 mm.
Alkali waters, sodic soils, amendments, gypsum responses
