Performance of groundnut (Arachis hypogaea)-cowpea (Vigna unguiculata) cropping system under various salinity levels in black clay soils of Saurashtra, Gujarat

A field experiment was conducted at Directorate of Groundnut Research, Junagadh during 2010–11 to evaluate the performance of groundnut (Arachis hypogaea L.)-cowpea (Vigna unguiculata L.) cropping system under various salinity levels in calcareous saline black clay soil of Saurashtra region of Gujarat. Results revealed that water and soil salinity up to 2.0 and 1.4 dS m⁻¹, respectively can be safely used for realizing optimum pod yield of groundnut. Among the tested genotypes, SG 99 and TPG 41 were found to be more tolerant than other genotypes. On the other hand, cowpea thrives best at 0.5 dS m⁻¹ and thereafter, significant reduction in yield was recorded. With an increase in the salinity of the irrigation water, the soil salinity in the root zone increased both in groundnut and cowpea crops but the buildup in salinity was more in cowpea than in kharif groundnut plots mainly owing to availability of sufficient rain water to leach down the salt below the root zone in case of groundnut crop.