Rationalization of nitrogen through crop residue and real time application in rice rice cropping system

Abstract

A field experiment entitled Rationalization of nitrogen through crop residue and real time newlineapplication in rice-rice cropping system was carried out for two consecutive years during 2020- newline21 and 2021-22 starting with kharif rice followed by rabi rice in the research farm of OUAT, newlineBhubaneswar. The experiment was carried out in a split plot design having 24 treatment newlinecombinations and 3 replications. In main plot, there were 6 treatments consist of rice residue newlinemanagement and those approaches for the system as a whole were laid out in such a way that it newlinevaries from residue removal to residue incorporation, C1= Rice residue removal, C2 = In-situ open newlineburning of rice residues, C3 = In-situ soil incorporation of rice residues, C4 = C3 + 20 kg N ha-1 newline(starter), C5 = C3 + 20 kg N ha-1+ 20 kg P2O5 ha-1, C6 = C3 + Waste-decomposer (500 l ha-1). In newlinesub-plot, there were 4 treatments consist of nitrogen management which approaches for the system newlinecomprised of N1 = Soil test-based nitrogen in splits as ¼ at basal, ½ at tillering and ¼ at PI, N2 = newlineBasal dose + Leaf colour chart (LCC)-based N management N3 = Basal dose + Chlorophyll meter newline(SPAD meter)-based N management, N4 = Integrated nitrogen management (75% N through newlineinorganic source + 25% N through FYM). In-situ incorporation of rice residues along with 20 kg newlineN ha-1 and 20 kg P2O5 ha-1 resulted in the maximum rice grain yield of 10.6 t ha-1, net monetary newlinereturn of Rs.82,528 ha-1, system productivity of 29.17 kg ha-1day-1 and profitability of Rs.226 ha- newline1day-1 in rice-rice production system, whereas, integrated N management (75% inorganic + 25% of newlineFYM) resulted in the maximum yield of 10.4 t ha-1, net monetary return of Rs.75,880 ha-1, system newlineproductivity of 28.53 kg ha-1day-1 and profitability of Rs.208 ha-1day-1. Soil bulk density reduced newlineby 5.4%, but pH, OC, available N, P and K increased by 8.28%, 14.5%, 0.57%, 18.8% and newline17.29% over the initial status of 1.47 g/cm3, 5.67, 0.48%, 228 kg ha-1, 18 kg ha-1and 122 kg ha-1, newlinerespectively due to in-situ incorporation of rice res