Effect of zinc on blackgram in rice-blackgram cropping system of coastal saline soils

A field experiment was conducted during kharif and rabi seasons of 2002–2003 and 2003–2004 on a saline soils, to study the effect of various levels, methods of application and residual effect of Zn on yield, nutrient concentration and uptake of blackgram (Vigna mungo). Twelve treatments comprising of four ZnSO₄levels (0, 12.5, 25 and 50 kg ha⁻¹) were distributed to the two crops of rice-blackgram in a cropping system. The maximum grain and haulm yields of blackgram were recorded with treatment that received 25 kg ZnSO₄ha⁻¹ to blackgram. The effect of all foliar treatments applied at different stages of crop proved to be at par with each other. The performance of the treatments was in the order: soil application > foliar treatments > residual fertility. The nutrient status of soil at the end of rice-blackgram cropping sequence indicated that the available N and Zn status of soil increased and that of K to decrease when compared with the initial soil status.