Can Knowledge-Based Practices Achieve High Yields with Lower Input and GHG Emissions in the Chinese Orchard System?

Abstract

The continuous improvement of the Chinese people’s lifestyle and consumption level and the promotion of healthful and reasonable diets have created a greater demand for fruit production. There is an urgent to determine how to meet the increasing demand for fruit, with lower inputs and environmental costs, because the Chinese fruit production has excessive agricultural input and relatively high environmental burden of greenhouse gas (GHG) emissions. This study conducted a meta-analysis of the experimental results of 307 conventional management measures and 333 optimized management measures. We found that by taking appropriate optimization measures such as N reduction, coupling of water and fertilizer and increasing organic carbon, has not only the fruit yield increased by 16.1% (5 Mg ha −1 year −1 ) but also the GHG emissions of the entire orchard system have also been drastically reduced by 65.4%. Net GHG balance has decreased from 11.3 ± 0.3 to 3.9 ± 0.3 Mg of CO 2 equivalent (CO 2 e) ha −1 year −1 , and GHG intensity per unit product has decreased from 3.6 ± 0.1 to 1.1 ± 0.1 kg of CO 2 e kg −1 . The main sources of total GHG emissions are from upstream production and transportation, due to N fertilizer application, mechanical irrigation energy, and N-fertilizer-induced soil N 2 O emissions. Our results highlight that the Chinese fruit production system has a large room to reduce GHG emissions by applying the mentioned optimization measures in above, and our findings will provide some guidance for agricultural carbon peak.