Performance of Maize Zea mays L Hybrids to Time Rate and Sources of Nitrogen on Productivity and Resource Use Efficiency

Abstract

Two field experiments were conducted during rabi 2021-22 and 2022-23 at the Main newlineAgricultural Research Station, UAS, Dharwad, Karnataka on clay soil to evaluate the effect of newlinetime, rate and sources of nitrogen on productivity and resource use efficiency of maize newlinehybrids. The first experiment was laid out in split-plot design with three replications and 24 newlinetreatment combinations. The main plot consisted of six hybrids (H) viz., GH-0727, NK-6240, newlineDKC-9133, BRMH-8, DKC-7204, RCRMH-2 and the sub-plot consisted of four nitrogen newlinelevels (N in kg ha-1) viz., 0, 100, 150 and 200. Pooled results of the experiment showed that N newlineapplication at 200 kg ha-1 with NK-6240 recorded significantly higher grain yield (9015 kg newlineha-1), stover yield (11706 kg ha-1), nitrogen uptake (258.6 kg ha-1), gross returns (` 1,97,778 newlineha-1), net returns (` 1,26, 791) and B-C ratio (2.79) with superior growth and yield attributes. newlineHowever, DKC-9133 with 200 kg N ha-1 was on par with the superior treatment. newlineSignificantly higher agronomic nitrogen use efficiency was recorded with lower N level i.e., newline100 kg ha-1 with NK-6240 (58.67 kg kg-1). Based on the yield potential of maize hybrids newlineunder two contrasting N-conditions i.e., 100 and 200 kg N ha-1, maize hybrids were newlinecategorized into efficient-efficient hybrids which are efficient under both the N conditions newline(NK-6240 and DKC-9133), low-nitrogen efficient hybrids which are efficient under low N newlineconditions (RCRMH-2) and nonefficient-nonefficient hybrids which are inefficient under both newlinehigh and low N conditions (GH-0727, BRMH-8 and DKC-7204). newlineThe second experiment consisted of two maize hybrids (H) viz., NK-6240 and DKC- newline9133 with eight N management treatments including 0 kg N ha-1, 150 kg N ha-1 (RDN) newlinethrough conventional fertilizers and three nitrogen rates viz., 75, 100 and 125 per cent of newlinerecommended nitrogen (RDN) through conventional fertilizers and liquid nano-urea in two or newlinethree splits. The experiment was laid out in randomized complete block design with three newlinereplications. The two maize hybri