绿肥配施增效产品降低旱地麦田温室气体排放及碳足迹OA

[Objective]A field experiment was conducted to investigate the effects of green manure(GM)crops combined with enhanced-efficiency products on greenhouse gas emissions(GHGs)and carbon(C)footprints in the dryland summer GM-winter wheat rotation system on the Loess Plateau,so as to provide the theoretical basis and technical parameters for fully tapping the emission reduction and C fixation potential of GM crops,and evaluating its environmental benefits in this cropping system.[Method]The GHGs patterns and net balance of soil C pool in summer GM-winter wheat rotation system of black beans(Phaseolus vulgaris L.)and rapeseed(Brassica napus L.)combined with different enhanced-efficiency products were measured from 2023 to 2024.There were 9 treatments,including:fallow(control),black beans sown alone,black beans+composite biological bacteria(Zaoyijia No.1),black beans+bacterium(Bacillus beresii B22),black beans+sepiolite,rapeseed sown alone,rapeseed+absorbent polymer(Shouke),rapeseed+actinomycetes(Streptomycete rochei D74),and rapeseed+sepiolite,each with 3 replications.C footprints were quantified and evaluated comprehensively,and the suitable GM+product combinations for C sequestration and GHGs emission reduction in drylands were screened.[Result](1)Compared with black beans sown alone,black beans+bacterium significantly reduced N2O and CO2 emissions,and global warming potential(GWP),with an average decrease of 29.3％,17.5％,and 17.8％,respectively,reduced 21.6％GHGs intensity(P＞0.05),and increased 7.8％wheat yield(P＞0.05).(2)Black beans+bacterium showed the highest dry biomass(4 230 kg-hm-2)and C input(1 750 kg·hm-2)and decreased 43.6％(P＜0.05)C footprints compared to fallow.(3)Compared with rapeseed sown alone,rapeseed+sepiolite significantly reduced N2O and CO2 emissions,and GWP,with an average decrease of 52.0％,16.9％,and 17.6％,respectively.(4)Rapeseed+sepiolite showed the highest dry GM biomass(2 723 kg·hm-2)and reduced 27.0％(P＜0.05)C footprints compared with fallow.[Conclusion]Introducing the optimized mixture of black beans+bacterium and rapeseed+sepiolite into the summer GM-winter wheat system in the Loess Plateau effectively reduced the GHGs and GWP after incorporating the GM crops,boosted C input,and diminished the C footprints of the crop growth period.This study established a green and clean production model that promoted grain quality,fertilizer use efficiency,C sequestration,and emission reduction,and accelerated the high-quality development of"ecological priority,green and low-carbon"in drylands.