PJB-2021-474
IMPROVING WHEAT-PRODUCTIVITY AND SOIL-FERTILITY THROUGH NITROGEN MANAGEMENT
Shehryar Khan
Abstract
Soil fertility and organic matter in our soils are on decline. Organic and mineral nitrogen (N) fertilizers are important measures to increase wheat yield and sustain fertility and productivity of soil. However, understanding of how combinations of both sources can be used to improve the yield as well as soil fertility is limited. Therefore a field experiment was carried out to study the effect of different N sources, forms and ratios for improving wheat productivity and soil fertility. The experiment was carried out at Agronomy Research Farm the University of Agriculture Peshawar in winter 2017-2018 and 2018-2019. The experiment was consisted of different organic amendments as sources of nitrogen i.e. rice residues, mung bean residues and cattle manures applied in two different forms i.e. compost, non-compost and different organic-inorganic N ratio. N ratios was managed in such a way that each plot received 50, 75 and 100% of N from organic source (rice residues, mung bean residues and cattle manures) and the rest from urea. All the treatments were analyzed for nutrients content (N, P and K) and were applied at such rate that 120 kg N ha-1 was desired from each treatment. One control with no N application was used in the experiments for comparison. Data were recorded on various phenological, growth, yield and yield components as well as grain quality and soil parameters. The results of the experiment revealed significant effect of different sources, forms and ratios of N on growth, yield and soil parameters. Phenology was significantly delayed by cattle manure except days to emergence. Among different organic material used as source of nitrogen, application of cattle manure produced taller plants (97.3 cm) with greater leaf area (140.1 cm2) and leaf area index (3.8). Similarly application of N from cattle manure produced more number of spikes m-2 (257), grains spike-1 (52), heavier grains (43.8 g), biological (8540 kg ha-1) and grain yield (3546 kg ha-1) as well as harvest index (41.5%). Among grain quality and soil parameters application of cattle manure increased grain proteins (13.1%), gluten (21.4%) and N contents (2.26%), soil organic carbon (0.77%), soil total N (0.094%), soil electrical conductivity (0.229 dS m-1) and reduced soil bulk density (1.17 g cm-3). Among various forms of organic materials, application of organic material in the form of compost delayed phenology, increased plant height, leaf area, leaf area index, spikes m-2, grains spike-1, thousand grains weight, biological yield, grain yield and harvest index. Application of composted organic N sources increased grain N (2.21%), gluten (20.9 %) and crude proteins contents (12.8%) , total N uptake (144.6 kg ha-1), soil N (0.090%), organic C (0.75%), soil pH (7.83) and electrical conductivity (0.227 dS m-1) and reduced bulk density (1.17 g cm-3) of soil. Regarding N ratios, application of organic and mineral N in 50:50 ratios produced taller plants (97.2 cm) with greater leaf area (140 cm2) and leaf area index (3.8), whereas physiological maturity (169 days) was delayed with sole organic N. Likewise, higher (263) number of spikes m-2, grains spike-1 (52), heavier grains (43.8 g), biological (8652 kg ha-1) and grain yield (3762 kg ha-1) and harvest index (43.5%) were recorded with 50% organic and 50% mineral N. Among grain quality and soil parameters, application of N in 50:50 ratios increased grain proteins (13.2%), gluten (21.3%) and N contents (2.28%), total N uptake (146.8 kg ha-1) and soil electrical conductivity (0.231 dS m-1). Whereas, sole organic N fertilizers indicated higher soil organic carbon (1%) and soil total N (0.091) and reduced soil bulk density (1.16 g cm-3). It is concluded that application of cattle manure in the form of compost coupled with inorganic N in 50:50 ratios can substitute chemical fertilizers and hence recommended for higher wheat yield, quality and soil fertility.
To Cite this article:
Download
