施石膏对水稻产量和甲烷排放影响的荟萃分析

Effects of gypsum application on grain yield and methane emissions in rice paddies: a global meta-analysis

  • 摘要: 石膏是一种常见的稻田土壤改良剂, 施石膏对水稻产量和稻田温室气体排放影响的荟萃分析尚鲜见报道。本研究采用Meta分析方法, 探究施石膏对水稻产量和稻田温室气体排放的影响。以不施石膏为对照, 施石膏为处理, 在全球尺度上筛选出了74篇文献, 建立了包含382对水稻产量、39对甲烷(CH4)排放、10对氧化亚氮(N2O)排放、10对综合温室效应(GWP)和10对温室气体排放强度(GHGI)观测值的数据库。针对不同的石膏施用措施(类型和施用量)、基础土壤性状(pH值、有机碳含量和质地)以及稻田管理方式(氮肥施用量、灌溉制度、水稻品种类型和试验类型), 探究施石膏对水稻产量和稻田CH4排放的影响。从总效应来看, 与不施石膏相比, 施石膏显著增加了水稻产量(+58%), 降低了稻田CH4排放(−47%)、GWP(−22%)和GHGI(−31%), 而对N2O排放影响不显著。脱硫石膏对水稻增产和稻田CH4减排的效应显著高于普通石膏和磷石膏。当施用量<2 t·hm−2时, 石膏对水稻产量影响不显著; 当施用量≥2 t·hm−2时, 石膏对水稻的增产效应随石膏施用量的增加而增加。随着土壤pH增加, 施石膏对水稻产量的增幅显著增加。石膏施用量和土壤pH对水稻产量存在显著的互作效应。在土壤pH<8.5条件下, 施石膏对水稻产量影响不显著; 在土壤pH≥8.5条件下, 水稻产量随着石膏施用量的增加而增加。稻田CH4减排效应随石膏施用量的增加而显著增加。综上, 施石膏显著提高了水稻产量, 同时降低了稻田温室气体排放, 本研究结果可为评估施石膏对全球水稻丰产和缓解气候变暖提供数据支撑。

     

    Abstract: Gypsum is a widely recommended soil amendment for rice paddies, but a meta-analysis of the responses of rice yield and greenhouse gas emissions to gypsum application has less been reported. In this study, a global meta-analysis was conducted to quantify the effects of gypsum application on rice yield and greenhouse gas emissions. The dataset was collected from 74 studies involving 382 pairs of rice yield observations, 39 pairs of methane emission observations, 10 pairs of nitrous oxide emission observations, 10 pairs of area-scaled global warming potential (GWP) observations, and 10 pairs of yield-scaled global warming potential (GHGI) observations, where the absence of gypsum acted as the control and the application of gypsum acted as the treatment. Based on a meta-analysis, the effects of gypsum application on rice yield and paddy CH4 emissions were examined under different gypsum application measures (type and application rate), soil properties (pH, organic carbon content, and texture), and field management methods (N rate, irrigation regime, rice type, and experiment type). Overall, gypsum application significantly increased rice yield (+58%) and reduced CH4 emissions (−47%), GWP (−22%), and GHGI (−31%), but did not affect N2O emissions relative to those without gypsum application. The magnitude of the increase in rice yield and reduction in CH4 emissions of desulfurization gypsum was significantly higher than that of gypsum and phosphogypsum. Applying gypsum increased rice yield at gypsum rates ≥ 2 t·hm−2, while no significant effects were observed at gypsum rates < 2 t·hm−2. The magnitude of the increase in gypsum application-induced rice yield increased with increasing soil pH. The gypsum rate and soil pH showed a positive interactive effect, whereby the increase in rice yield increased with the gypsum rate in the initial soils with pH ≥ 8.5 but remained stable at soil pH < 8.5. Gypsum application induced a reduction in CH4 emissions with increasing gypsum application rate. Our results indicate that gypsum application could increase rice yield and reduce greenhouse gas emissions, providing a theoretical basis for evaluating the effects of gypsum application on high rice yield and mitigating global warming.