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Background Soil application of biochar and straw alone or their combinations with nitrogen (N) fertilizer are becoming increasingly common, but little is known about their agronomic and environmental performance in semiarid environments. This study was conducted to investigate the effect(s) of these amendments on soil properties, nitrous oxide (N2O) and methane (CH4) emissions and grain and biomass yield of spring wheat (Triticum aestivum L.), and to produce background dataset that may be used to inform nutrient management guidelines for semiarid environments. Methods The experiment involved the application of biochar, straw or urea (46% nitrogen [N]) alone or their combinations. The treatments were: CN0–control (zero-amendment), CN50 –50 kg ha–1 N, CN100–100 kg ha–1 N, BN0 –15 t ha–1 biochar, BN50–15 t ha–1 biochar + 50 kg ha–1 N, BN100–15 t ha–1 biochar + 100 kg ha–1 N, SN0 –4.5 t ha–1 straw, SN50 –4.5 t ha–1 straw + 50 kg ha–1 N and SN100–4.5 t ha–1 straw + 100 kg ha–1 N. Fluxes of N2O, CH4 and grain yield were monitored over three consecutive cropping seasons between 2014 and 2016 using the static chamber-gas chromatography method. Results On average, BN100reported the highest grain yield (2054 kg ha–1), which was between 25.04% and 38.34% higher than all other treatments. In addition, biomass yield was much higher under biochar treated plots relative to the other treatments. These findings are supported by the increased in soil organic C by 17.14% and 21.65% in biochar amended soils (at 0–10 cm) compared to straw treated soils and soils without carbon respectively. The BN100treatment also improved bulk density and hydraulic properties (P |
