Combined applications of organic and synthetic nitrogen fertilizers for improving crop yield and reducing reactive nitrogen losses from China's vegetable systems: A meta-analysis. (15th January 2021)

• Record Type: Journal Article
• Authors: Liu, Bin; Wang, Xiaozhong; Ma, Lin; Chadwick, Dave; Chen, Xinping
• Is Part Of: Environmental pollution. Volume 269(2021)
• Publication Date: 2021-01-15
• Subjects: Organic fertilizer -- Synthetic N fertilizer -- Substitution rate -- Vegetable systems -- Yield -- Reactive nitrogen losses; N nitrogen -- Nr reactive nitrogen -- NUE N use efficiency -- N2O nitrous oxide -- NH3 ammonia -- SOC soil organic carbon -- GHG greenhouse gas -- EFs emission factors -- RDA Redundancy analysis -- SOM soil organic matter -- STN soil total nitrogen -- ON organic N -- SN synthetic N -- SR synthetic N substitution rate -- GWP global warming potential; Pollution -- Periodicals; Pollution -- Environmental aspects -- Periodicals; Environmental Pollution -- Periodicals; Pollution -- Périodiques; Pollution -- Aspect de l'environnement -- Périodiques; Pollution -- Effets physiologiques -- Périodiques; Pollution; Pollution -- Environmental aspects; Periodicals; Electronic journals; 363.73
• DOI: 10.1016/j.envpol.2020.116143
• Languages: English
• ISSNs: 0269-7491

Abstract

Abstract: The combined application of organic and synthetic nitrogen (N) fertilizers is being widely recommended in China's vegetable systems to reduce reliance on synthetic N fertilizer. However, the effect of substituting synthetic fertilizer with organic fertilizer on vegetable productivity (yield, N uptake and nitrogen use efficiency) and reactive nitrogen (Nr) losses (N2 O emission, N leaching and NH3 volatilization) remains unclear. A meta-analysis was performed using peer-reviewed papers published from 2000 to 2019 to comprehensively assess the effects of combined application of organic and synthetic N fertilizers. The results indicate that overall, the vegetable yield, N2 O emission and NH3 volatilization were not significantly changed, whereas N leaching was reduced by 44.6% and soil organic carbon (SOC) concentration increased by 12.5% compared to synthetic N fertilizer alone. Specifically, when synthetic N substitution rates (SRs) were ≤70%, vegetable yields and SOC concentration were increased by 5.5%–5.6% and 13.1–18.0%, and N leaching was reduced by 41.6%–48.1%. At the high substitution rate (SR>70%), vegetable yield was reduced by 13.6%, N2 O emission was reduced by 14.3%, and SOC concentration increased by 16.4%. Mixed animal-plant sources of organic N preferentially increased vegetable yield and SOC concentration, and reduced N2 O emission and N leaching compared with single sources of organic-N. Greenhouse gas (GHG) emission was decreased by 28.4%–34.9% by combined applications of organic and synthetic N sources, relative to synthetic N fertilizer alone. We conclude that appropriate rates (SR ≤ 70%) of combined applications of organic and synthetic N fertilizers could improve vegetable yields, decrease Nr and GHG emission, and facilitate sustainable development of coupled vegetable-livestock systems. Graphical abstract: Image 1 Highlights: Yields increased when substitution rate of synthetic N with organic source was ≤70%. Substitution of synthetic N fertilizer with organic fertilizers reduced N leaching loss. Substitution of synthetic N fertilizer with organic fertilizers increased soil carbon sequestration. Combined applications of organic and synthetic N fertilizers decreased net GWP at field level. Abstract : Capsule: Appropriate substitution of synthetic N fertilizer with organic fertilizers could increase vegetable yields and SOC concentration, and reduce N leaching and GHG emission.