施肥对我国农田土壤易氧化有机碳影响的整合分析

Effects of fertilization on soil readily oxidizable carbon of croplands in China:a meta-analysis

土壤易氧化有机碳(ROC)作为土壤有机碳的重要组成部分,与土壤养分供应密切相关,在提升土壤肥力方面有着重要意义。施肥是影响土壤易氧化有机碳的重要措施之一,探讨不同土壤性质和气候条件下施肥对ROC变化的影响,为农田合理施肥和培肥地力提供理论依据。收集了2000-2022年公开发表的文献78篇,建立了378组包含不同施肥条件下表层土壤ROC含量的数据库。采用整合分析和随机森林方法分析全国农田土壤ROC的提升幅度在不同施肥措施之间的差异,定量分析不同肥料施用量,土壤性质和气候条件等因素对ROC提升的相对贡献。结果表明:(1)施肥能显著提高ROC的含量,且施用有机肥(单施或配施)对ROC的提升幅度(70.1%)是施用化肥(17.7%)的4.1倍。随着有机肥施用量的增加,ROC的提升幅度也在逐渐提高。(2)在不同土壤养分含量下,施肥均能显著增加ROC含量,但在养分较低的土壤中ROC的提升幅度显著高于养分较高的土壤;中性土壤施用化肥后对ROC的提升幅度(34.8%)显著高于酸性土壤(16.6%)和碱性土壤(10.4%),但施用有机肥对ROC的提升幅度在不同pH下的土壤中无显著差异。(3)不同气候条件下,施肥对ROC的提升幅度存在显著差异,寒冷干旱地区施用有机肥对ROC的提升幅度显著高于温暖湿润地区。(4)不同施肥条件下(施用化肥和有机肥)均是土壤性质对ROC的提升幅度起决定性作用。因此,建议在我国构建以有机肥为核心的肥料施用体系,因地制宜地选择有机肥配施化肥的施用量,从而改善土壤性质,以最大的程度提高ROC含量,提升土壤肥力。

As an important component of soil organic carbon,readily oxidizable carbon(ROC)is closely related to soil nutrient supply and plays an important role in improving soil fertility.Fertilization is one of the important measures to affect soil ROC.The change law of ROC after fertilization under different soil properties and climate conditions was discussed,which provided theoretical basis for rational fertilization and fertility improvement in farmland.78 published literatures from 2000 to 2022 were collected,and 378 groups of ROC content database were established under different fertilization treatments.Meta-analysis was used to analyze the difference of ROC increase range among variable fertilization measures in farmland soil of China,and the relative contribution of different fertilizer application rates,soil properties and climate conditions to ROC enhancement was quantitatively analyzed by random forest.The results showed that:(1)Application of organic fertilizer significantly increased ROC content,and the increase of organic fertilizer(70.1%)was 4.1 times than that of chemical fertilizer(17.7%).With the increase of organic fertilizer application rate,the increase of ROC was gradually increasing.(2)Under different soil nutrient contents,fertilization significantly increased the ROC content,but the increase of ROC in soil with low nutrients was significantly higher than that in soil with high nutrients.The application of chemical fertilizers in neutral soil significantly increased ROC(34.8%)compared to acidic soil(16.6%)and alkaline soil(10.4%),while the application of organic fertilizers showed no significant difference in the increase of ROC.(3)Under different climatic conditions,there were significant differences in the increase of ROC by fertilization,and the increase of ROC by organic fertilizer application in cold and dry areas was significantly higher than that in warm and humid areas.(4)Soil properties played a crucial role in the increase of ROC under fertilization conditions(applying chemical fertilizer and organic fertilizer).Therefore,it is suggested to establish a fertilization strategy with organic fertilizer as the core in China,and select the application amount of organic fertilizer combined with chemical fertilizer according to local conditions in order to improve soil properties,maximize ROC content and further improve soil fertility.