Effects of new fertilizers on the yield and soil biological activity of three major food crops: A global meta-analysis

Objectives In recent years, with the transformation of agricultural development mode from resource consumption to green ecology, the development of new fertilizers has become a hot topic. Recent available studies mostly focused on the effects of new fertilizers on the crop yield, nitrogen (N) uptake and nitrogen use efficiency (NUE), but our understanding about their effect on soil biological activity was relatively limited. This study aims to analyze the effects of new fertilizer on the yield of three major food crops (wheat, maize and rice) and soil biological activity, and also to provide a scientific basis for the wide production and application of new fertilizers.

Methods In this study, we obtained the data from “CNKI” and “Web of Science” databases. A total of 29 relevant papers conducted in field trials were obtained with “wheat”, “maize”, “rice”, “yield”, “microbial biomass”, “enzyme activity” and “new fertilizer” as the keywords, producing a total of 545 data groups coming from 32 independent trials. Using conventional fertilizers as the control and new fertilizers as the experimental group, Meta-analysis was used to integrate the effects of new fertilizers application on crop yield, enzyme activity and soil microbial biomass.

Results The yield, aboveground N uptake and NUE of three crops were significantly increased by new fertilizers application, with an increment rate of 8.4%, 9.9% and 36.8%, respectively, compared with those of conventional fertilizers application. Similarly, the application of new fertilizers significantly increased soil microbial biomass nitrogen (14.6%), but had no significant effect on soil microbial biomass carbon. Soil phosphate metabolism-related enzymes activities (8.6%) and oxide-related enzymes activities (5.7%) were significantly increased by applying new fertilizers, but no significant difference was found for soil carbon and nitrogen cycling enzyme activities between these two treatments.

Conclusions The application of new fertilizers increased the yield, aboveground N uptake and NUE of three major crops, and also increased soil microbial biomass N, soil phosphate metabolism-related enzymes activity and oxide-related enzymes activity, and further improved the soil biological activity of agricultural ecosystem.