Partial substitution of manure reduces nitrous oxide emission with maintained yield in a winter wheat crop.

Conventional fertilization of agricultural soils results in increased NO emissions. As an alternative, the partial substitution of organic fertilizer may help to regulate NO emissions. However, studies assessing the effects of partial substitution of organic fertilizer on both NO emissions and yield stability are currently limited. We conducted a field experiment from 2017 to 2021 with six fertilizer regimes to examine the effects of partial substitution of manure on NO emissions and yield stability. The tested fertilizer regimes, were CK (no fertilizer), CF (chemical fertilizer alone, N 300 kg ha, PO 150 kg ha, KO 90 kg ha), CF + M (chemical fertilizer + organic manure), CFR (chemical fertilizer reduction, N 225 kg ha, PO 135 kg ha, KO 75 kg ha), CFR + M (chemical fertilizer reduction + organic manure), and organic manure alone (M). Our results indicate that soil NO emissions are primarily regulated by soil mineral N content in arid and semi-arid regions. Compared with CF, NO emissions in the CF + M, CFR, CFR + M, and M treatments decreased by 16.8%, 23.9%, 42.0%, and 39.4%, respectively. The highest winter wheat yields were observed in CF, followed by CF + M, CFR, and CFR + M. However, the CFR + M treatment exhibited lower NO emissions while maintaining high yield, compared with CF. Four consecutive years of yield data from 2017 to 2021 illustrated that a single application of organic fertilizer resulted in poor yield stability and that partial substitution of organic fertilizer resulted in the greatest yield stability. Overall, partial substitution of manure reduced NO emissions while maintaining yield stability compared with the synthetic fertilizer treatment during the wheat growing season. Therefore, partial substitution of manure can be recommended as an optimal N fertilization regime for alleviating NO emissions and contributing to food security in arid and semi-arid regions.