Effects of Sequential and Tank Mix Applications of Zinc, Iron and Nitrogen on Symbiotic Parameters, Productivity and Economics of Chickpea (Cicer arietinum L.) Under Field Conditions

The present investigation was undertaken to study the effect of individual (sequential) and tank mix (simultaneous) applications of nutrients, i.e. zinc (Zn), iron (Fe) and nitrogen (N) on different symbiotic parameters, productivity and economics of chickpea. A 2-year field study was conducted in randomized complete block design, which comprised twelve treatments in spraying combinations of three nutrients (Zn, Fe and N) at flowering and pod formation stages of chickpea. The nutrients were applied as 0.5% zinc sulphate (ZnSO4), 0.5% ferrous sulphate (FeSO4) and 2% urea either as sole, combination of any two or all the three nutrients as sequential as well as tank mix foliar sprays. The sequential application of ZnSO4 (0.5%), FeSO4 (0.5%) and urea (2%) recorded the highest number of nodules, dry weight of nodules, leghaemoglobin content, chlorophyll content and grain yield (1906 and 1947 kg ha(-1) in the first and second year, respectively) closely followed by tank mix application of the same nutrients (1894 and 1925 kg ha(-1)). However, tank mix application of all the three nutrients recorded higher net returns (715.52 and 850.08 US$ ha(-1)) and benefit-cost ratio (1.42 and 1.67) over sequential application (701.02 and 841.10 US$ ha(-1) and 1.33 and 1.58) of the three nutrients. Furthermore, application of the three nutrients either as sequential or tank mix provided higher productivity as well as economic returns over single or combined application of any of the two nutrients. Tank mix application of ZnSO4 (0.5%), FeSO4 (0.5%) and urea (2%) at flowering and pod formation stages is a new technique for increasing the productivity and economic returns of chickpea, which requires a special attention for improving the socio-economic status of chickpea growers.