Growth and physiological indices changes in maize with differential residue and nitrogen management under conservation agriculture

Abstract

A field experiment was conducted during kharif season 2015 for exploring influence of differential residue and nitrogen management practices on growth parameters and physiological indices of maize under conservation agriculture on a sandy loam soil at New Delhi. The treatments consisted of two cropping systems: maizemustardmungbean (MMuMb) and maize-wheatmungbean (MWMb); two residue management practices of with (WR) and without residue (WoR) and four N management practices of control, prilled urea (PU), sulphur coated urea (SCU) and neem coated urea (NCU) arranged in split-split plot design and replicated thrice. The results of the study indicated that growth parameters, viz., plant height, dry matter accumulation (DMA), leaf area and leaf area index (LAI) and physiological indices viz., crop growth rate (CGR), relative growth rate (RGR) and net assimilation rate (NAR) in maize were increased significantly with residue retention and coated urea application. The yield attributes of maize were also enhanced by the application of WR, MWMb and NCU. After water stress significant decrease in canopy temperature was recorded with WR (-3.39oC) compared to WOR (-1.84oC). The higher dry matter accumulation (218 g/plant) was recorded under MWMb compared to MMuMb (184 g/plant) cropping system. The highest and least leaf area and LAI in maize plants were recorded under NCU application and absolute control, respectively. SCU and PU remained at par with each other with respect to both leaf area and LAI. The highest SPAD values were observed with the NCU at 30 and 90 DAS, which were at par with SCU at 30 DAS and PU and SCU at 90 DAS. Thus, the basal application of NCU and residue retention in MWMb system was could be opted for enchaining growth parameters and physiological indices in maize under conservation agriculture.