Legume cover with optimal nitrogen management and nitrification inhibitor enhanced net ecosystem economic benefits of peach orchard

Abstract

Peach (Prunus persica L.), as a traditional kind of fruits in China, was extremely dependent on large application of nitrogen (N) fertilizer to maintain high fruit yield and commercial income, resulting in raising environmental damage risk. Therefore, a three-year field trail was conducted to clarify the environmental N loss under conventional management, investigate the positive effects of optimal N management, legume cover and 3,4-dimethylpyrazole phosphate (DMPP) on N input/output and the net ecosystem economic benefits (NEEB). There are four treatments in this study: conventional fertilizer management with 521.1 kg N ha^-1 yr^-1 input (CU); optimal N management including 406.4 kg N ha^-1 yr^-1 input and deep fertilization (OP); DMPP was added to OP at rate of 1 % (w/w) (OPD); legume (white clover) was covered to OPD (OPDG). Results showed 102.9 kg N ha^-1 was removed by annual fruit and residues (including pruned branches, pruned and fallen leaves), while 70.2 kg N ha^-1 was lost to the environment by ammonia (NH₃), nitrous oxide (N₂O) and N runoff loss under the conventional fertilizer management. While, the optimal N management mitigated NH₃ volatilization about 49.3 %, further added DMPP abated N₂O emission by 61.4 %, besides covered white clover lowered N runoff loss by 64.5 %. The NEEB results revealed that optimal N management combined with added DMPP and covered white clover could minimize the production cost, reduce environmental damage cost by 35.9 %, increase fruit yield by 10.3 % and achieved the maximum NEEB with improvement of 27.1 %, in comparison of the conventional fertilizer management. Generally, conventional peach cultivation constituted overwhelming N loss to raise potential environmental risk. While, extending mode of optimized N management combined with DMPP and legume cover could not only realize high fruit revenue, but also abate environmental N losses, thereby should be considered as effective strategy for sustainable fruit cropping systems.

Keywords: Deep placement; Legume cover; Net environmental economic benefits; Nitrification inhibitor; Peach production; Reduced N input.