Soil Nitrous Oxide Emissions Following Crop Residues Management in Corn-Wheat Rotation Under Conventional and No-Tillage Systems

Abstract

Agricultural activity is the major anthropogenic source of nitrous oxide (N2O) emissions from terrestrial ecosystems. Conservation agriculture including crop residue management can play a key role in enhancing soil resilience to climate change and mitigating N2O emissions. We investigated the effects of crop residue rates, including 100 % (R100), 50 % (R50), and residue removal (R0), on N2O emissions in corn-wheat rotation under conventional (CT) and no-tillage (NT) systems. The key factors evaluated affecting N2O emissions included soil temperature, soil moisture, soil ammonium, and soil nitrate concentrations. Results showed that the N2O emissions increased with the increasing rate of residue under both CT and NT systems. Both R100 and R50 significantly ( p < .05) increased the N2O emissions compared to R0 during the annual rotation cycle. Soil moisture and mineral nitrogen (ammonium and nitrate) were the main driving factors that stimulated N2O emission in both CT and NT systems. In the NT and CT systems, cumulative N2O emissions showed a significant increase with R50 (+75.5 % in NT, +36.5 % in CT) and R100 (+134 % in NT, +40 % in CT) as compared to R0. Furthermore, no significant differences were found between R100 and R50 in the CT system, while in the NT system significant increases were observed for R100 compared to R50. Overall, our study justified as a first approach only during the first year that crop residue removal led to decreased N2O emissions under semi-arid conditions. However, due to the deteriorating impact of crop residue removal on crop productivity and soil C sequestration, this management method cannot be considered a sustainable agronomic practice. We suggest long-term studies to determine the appropriate rate of postharvest crop residue to achieve less N2O emissions and climate-friendly agricultural practices.

Environmental impacts of corn silage production: influence of wheat residues under contrasting tillage management types

“…The majority of Iranian agricultural soils are deficient in terms of organic matter presence and nutrient availability which severely affect crop production (Ayoubi et al, 2018 ; Mirzaei et al, 2021 ). Therefore, to achieve the optimal yield, more nitrogen fertilizers are used, resulting in increased GHG emissions and other contaminations (Mirzaei et al, 2022b ; Yazdanbakhsh et al, 2020 ). In addition, the use of poor agronomic practices (i.e., lack of crop rotation, improper methods of fertilizer application and irrigation) reduces nitrogen use efficiency and increases dependence on chemical fertilizers.…”

“…Exacerbated intensification and non-planned farming practices contribute significantly to increasing soil consumption and gas emissions to the environment (Mirzaei et al, 2022a , b ; Rodrigo-Comino et al, 2020 ; Smith et al, 2017 , 2021 ). However, to achieve land degradation neutrality in these areas considering the effects on carbon and nitrogen dynamics, agricultural practices such as reduced tillage and the use of crop residues could have direct (i.e., carbon sequestration, mitigation of greenhouse gases emissions, absorbing pollutants and other chemicals used in agriculture, reducing air pollutants) and indirect (i.e., reducing fuel and energy consumption) positive effects on global warming and environmental quality (Brennan et al, 2014 ; Liu et al, 2014 ; Mirzaei et al, 2022a ; Ravindra et al, 2019 ; Sindelar et al, 2019 ; Yao et al, 2013 ).…”

“…Annually, a massive amount of crop residues is produced but, unfortunately, these residues are burned or removed for fodder, energy production, or other purposes (Mirzaei et al, 2021 ; Rasoulzadeh et al, 2019 ). Furthermore, extensive use of conventional tillage systems, chemical fertilizers, and lack of proper crop rotation have caused a decline in organic matter, poor soil quality, lower crop performance, emission of greenhouse gases, and environmental pollution in the region (Mirzaei et al, 2022a , b ; Naseri et al, 2021 ). However, the implementation of conservation tillage methods and adequate management of crop residues can improve soil quality and crop production, as well as contribute to the mitigation of environmental impacts (Cerdà et al, 2016 ; Nunes et al, 2016 ; Rakkar et al, 2017 ; Whitbread et al, 2000 ).…”

Residue Management and Nutrient Stoichiometry Control Greenhouse Gas and Global Warming Potential Responses in Alfisols

“…The crop RR rate significantly impacts the availability of organic C in the soil, which is a critical factor in regulating soil microbial processes. By supplying energy and electron donors to denitrifiers and methanotrophs, crop residue reduces N 2 O to N 2 and methane to CO 2 [10][11][12][13]. A meta-analysis by Wang et al [14] demonstrated that the inconsistent effect of RR on GHG emissions (CO 2 , N 2 O, and CH 4 ) can be modified by multiple management factors, such as soil nutrients and residue placement in the soil.…”