Alleviation of salinity stress in chickpea byRhizobium inoculation or nitrate supply

Abstract

Influence of inoculation with efficient rhizobia or nitrate fertilization in alleviating salinity (NaCl, CaCl₂ and Na₂SO₄) stress was investigated in sand culture experiments. Shoot dry mass declined beyond salinity level corresponding to electrical conductivity (EC) 5.6 dS m⁻¹ in control or in inoculated plants and after EC 7.4 dS m⁻¹ in nitrate fed ones. Root growth was more sensitive and decreased at EC 3.3 dS m⁻¹. Nitrate reductase activity in leaves reduced at EC 3.3 dS m⁻¹ but in inoculated and nitrate fed plants it reduced at EC 5.6 dS m⁻¹. Na⁺ accumulation increased at EC 5.6 and 7.4 dS m⁻¹ in roots and, shoots, respectively. In inoculated and nitrate fed plants Na⁺ content in roots increased at EC 7.4 dS m⁻¹. Content of Ca²⁺ increased slightly only in shoots and content of K⁺ was unaffected. Besides inoculation, application of small doses of nitrogen should prove beneficial for legume cultivation in saline soils.