Manure substitution with appropriate N rate enhanced the soil quality, crop productivity and net ecosystem economic benefit: A sustainable rainfed wheat practice

Abstract

Partial substitution of organic fertilizer is adopted to increase production and alleviate farmland greenhouse gas (GHG) emissions. However, there is a lack of integrated assessment of soil quality, crop productivity, and environmental benefits through organic fertilizer substitution. Therefore, an in-situ experiment was conducted with the single nitrogen (N) treatments (120, 180, 240 kg N ha−1, expressed with N120, N180, N240, respectively) and partial substitution with manure fertilizer (each N treatment decreased by 30 kg N ha−1 and plus 2 t ha−1 pig manure, expressed with NM120, NM180, NM240, respectively) for rainfed wheat production on the Loess Plateau. A comparison between N and NM treatments showed that manure substitution treatments: 1) increased soil quality index by 50.9 − 57.4%, grain yield by 9.0 − 42.9%, total N accumulation by 8.6 − 31.1% and nitrogen recovery efficiency by 10.7 − 76.9%; 2) decreased N2O emission by 10.6 − 15.3% and CH4 uptake by 2.9 − 3.6%, whereas increased CO2 emission by 5.1 − 6.7%; 3) reduced the carbon footprint by 1.7 − 2.3 time mainly by the soil organic carbon sequestration. The global warming potential (GWP), Greenhouse gas emission intensity (GHGI), grain yield and net ecosystem economic benefit (NEEB) increased as the fertilizer rates increasing. NM180 had higher yield (average 6022 kg ha−1) and lower GWP (16489 kg CO2-eq ha−1) than N180, which obtained the smaller GHGI (2.67 kg CO2-eq kg−1) and maximum NEEB (4150 RMB ha−1). Overall, manure partial substitution with appropriate N rate enhances soil quality, crop productivity and environment benefit, which is a sustainable rainfed wheat practice.