RCR | 小麦、水稻和玉米体系中不同农业管理措施下N2O排放与产量权衡关系的全球荟萃分析

Fig. 1. (a) Global geographical distribution of field trial samples included in the meta-analysis; (b-d) Based on primary data and published meta-analysis data, the impacts of management practices on N2O emissions (b), crop yield (c), and yield-scaled N2O emissions (d) are respectively demonstrated. Colored points in the map correspond to different management practices, with point size proportional to the number of observations. Forest plot data present effect sizes (percentage) with error bars indicating 95% confidence intervals. Values adjacent to data points denote percentage effect sizes. Red, blue, and gray points represent significant positive, significant negative, and non-significant effects, respectively. Abbreviations: SY (synthetic fertilizer), OR (organic fertilizer), SY+OF (synthetic + organic fertilizer), OF_SY (Organic fertilizer substitution for synthetic fertilizer), EENF (enhanced-efficiency nitrogen fertilizer substitution substitution for synthetic fertilizer), SR (straw return), BI (biochar), PF (plastic film mulching), RNT (Reduced- and no-tillage), and ALL (cumulative effects of all treatments). Numbers in parentheses following treatments indicate observation counts. The map base layer delineates study regions and does not represent officially recognized national boundaries.

Fig. 2. Moderating effects of crop types on N2O emissions (a), yield (b), and yield-scaled N2O emissions (c) under different management practices. Forest plots display effect sizes (percentage) with error bars representing 95% confidence intervals. Values adjacent to data points indicate percentage effect magnitudes. Colored points denote significant positive (red), significant negative (blue), and non-significant effects (gray), with shape variants corresponding to distinct crop types. Numbers in parentheses following treatments indicate observation counts.

Fig. 3. Parameter estimates of climate, soil, and field management effects on N2O emissions (a), yield (b), and yield-scaled N2O emission variation (c) under different management practices. Light green, light blue, and pale yellow shading denote climate, soil, and field management factors, respectively. Mixed-effects meta-regression results are presented as mean percentage changes with error bars indicating 95% confidence intervals. Green, blue, and yellow points indicate statistically significant influences, while gray points represent non-significant effects.

Fig. 4. Spatial projections of the effects of various management practices on N2O emissions. Model performance evaluation and variable importance ranking are provided in Supplementary Fig.s S13, 14, 15.

Fig. 5. Spatial projections of the effects of various management practices on crop yield. Model performance metrics and variable importance rankings are available in Supplementary Fig.s S16, 17, 18.

Fig. 6. Spatial projections of the effects of various management practices on yield-scaled N2O emissions. Model validation statistics and predictor importance analyses are detailed in Supplementary Fig.s S19, 20, 21.

Fig. 7. (a) Global optimal distribution patterns of OF_SY, EENF, BI, RNT and SR practices; (b) Spatial projections of relative mean changes in yield-scaled N2O emissions under combined implementation of these five management practices. The pie chart illustrates the distribution of the five management practices, presenting a global overview along with a continental breakdown.