INTEGRATED NUTRIENT MANAGEMENT IN MAIZE BASED CROPPING SYSTEMS

Field: Agricultural and Biological Sciences (Life Sciences)

An experiment on “Integrated nutrient management in maize based cropping systems” was conducted at Regional Agricultural Research Station, Jagtial in red sandy loam soil during kharif and rabi, 2002-03 and 2003-04. The experiment was laid out in randomized block design for kharif maize (2002-03) with twelve treatments viz., 75, 100, 125 per cent recommended dose of nitrogen (RDN) through urea; 75 or 100 or 125 per cent RDN through urea + 25 per cent RDN through farm yard manure (FYM) or poultry manure (PM) or vermicompost (VC). In succeeding rabi, each of the kharif treatments were sub divided into four plots to accommodate blackgram and groundnut each at 50 and 100 per cent recommended dose of fertilizers (RDF) as sub treatments in split plot design with three replications. During 2003-04 kharif and rabi, the experiment was conducted at same site in split plot design and the results were analysed accordingly. In kharif, the grain, shank and stover yield, crop growth, dry matter production (DMP), N, P, K, Zn, Fe, Mn and Cu uptake, yield attributes and protein content of maize with application of 25 per cent RDN through FYM or PM or VC in combination with 125 per cent RDN through urea were significantly higher than that of 75 or 100 or 125 per cent RDN through urea. Oil content of maize grain was higher with conjunctive use of organics with 75 or 100 or 125 per cent RDN through urea than 75 or 100 or 125 per cent RDN through urea. The crop growth, nutrient uptake, yield attributes and yield of succeeding maize during 2003-04 did not vary due to residual effect of 50 and 100 per cent RDF applied to preceding rabi blackgram and groundnut. In rabi, crop growth, nutrient uptake, yield attributes, yield and oil content of groundnut and protein content of succeeding blackgram and groundnut were significantly higher due to residual effect of 25 per cent RDN through FYM or PM or VC in combination with 75 or 100 or 125 per cent RDN through urea applied to
preceding maize as compared to other treatments. There was no significant difference in yield attributes and yield of groundnut and blackgram due to application of 50 or 100 per cent RDF to these crops. After harvest of kharif and rabi crops; soil available N, P, K, Zn, Fe, Mn and Cu content were significantly higher with application of 25 per cent RDN through FYM or PM or VC in combination with 75 or 100 or 125 per cent RDN through urea than that of 75 or 100 or 125 per cent RDN through urea. Soil bulk density, organic carbon and infiltration were not influenced by different treatments during first year. However, during second year, there was significant decrease in bulk density and increase in organic carbon, infiltration rate, water holding capacity and porosity in former treatments than that in latter treatments. However, the soil available K and Zn was higher with VC than that of FYM and PM and the soil available N was higher with combination of manures with 125 per cent RDN through urea than their combination with 75 or 100 per cent RDN through urea to kharif maize. Soil pH and EC did not differ significantly either due to nitrogen in combination with organic manures applied to kharif maize or due to fertility levels applied to rabi blackgram and groundnut. Application of 100 per cent RDF to rabi blackgram and groundnut resulted in significant increase in soil available P, K, Zn than that of 50 per cent RDF. However, bulk density, porosity, water holding capacity, organic carbon, soil available N and Fe were not affected by these treatments. The infiltration rate, available soil K, Zn and Mn were significantly higher after groundnut than that after blackgram in sequence with kharif maize. Maize equivalent yield and production efficiency observed with 25 per cent RDN through FYM followed by PM in combination with 125 per cent RDN through urea were comparable with that of 25 per cent RDN through FYM or PM along with 100 per cent RDN through urea and 25 per cent RDN through VC with 125 per cent RDN through urea to kharif maize and were significantly higher than rest of the treatments. Net returns were significantly higher with 25 per cent RDN through PM followed by FYM integrated with 125 per cent RDN through urea than other treatments. B:C ratio recorded with application of 25 per cent RDN through PM in combination with 125 per cent RDN through urea was comparable with that of 25 per cent RDN through PM in combination with 100 per cent RDN through urea in both the years and 25 per cent RDN through FYM along with 100 or 125 per cent RDN through urea to kharif maize in 2003-04. Significantly lower maize equivalent yield, production efficiency, net returns, B:C ratio were recorded with application of 75 per cent RDN through urea. Maize-groundnut cropping system with 50 per cent RDF recorded comparable maize grain equivalent yield, production efficiency and net returns as that of 100 per cent RDF and significantly higher than that of maize-blackgram either with 50 or 100 per cent RDF. Vermicomposting and composting of crop residues of maize, blackgram and groundnut have increased N, P, K, Zn, Fe, Mn and Cu content over that of crop residues used and the nutrient content of vermicompost was higher as compared to respective composts.