Effect of integrated nutrient management on growth and yield of rabi onion and its residual effect on succeeding okra crop

Abstract

The field experiment was conducted to access the effect of inorganic fertilizers, organic manures and biofertilizers on growth and yield of rabi onion (Allium cepa L.) and its residual effect on succeeding crop okra. The experiment comprised of 36 treatment combinations and replicated three times, was laid out in split-plot design with three fertility levels (0, 75 and 100% of recommended dose of NPKS) and three treatments of organic manures (control, FYM @ 20 t ha-1 and poultry manure @ 5 t ha-1) were applied in main plots. Four bio-fertilizers (No inoculation, PSB inoculation, Azospirillum inoculation and PSB + Azospirillum inoculation) were applied in sub plots. The two year results of the study have clearly showed that application of inorganic fertilizers up to 75% RDF significantly increased all the growth parameters (plant height, number of leaves and chlorophyll content in leaves), yield and yield attributes (bulb diameter, yield of onion and okra). Similarly, application of poultry manure @ 5 t ha-1 significantly increased all the growth parameters, yield and yield attributes of onion. The maximum values for growth parameters, yield and yield attributes achieved on combined inoculation with PSB + Azospirillum. Application of 75 recommended doses of NPKS along with poultry manure @ 5 t ha-1 is better for realizing better bulb diameter and yield of onion. Further it may be concluded that application of 75% RDF of NPKS + 5 t ha-1 poultry manure is worth recommendable for farmers to get significantly better yield, net returns and maximum B:C ratio from onion and its succeeding crop okra by utilizing residual effect of treatment.