长期施肥对中国农田土壤溶解性有机碳氮含量影响的整合分析

A Meta-Analysis of Long-Term Fertilization Impact on Soil Dissolved Organic Carbon and Nitrogen Across Chinese Cropland

【目的】施肥是影响农田土壤溶解性有机碳、氮的重要因子。探讨在不同利用方式、熟制、土壤pH等条件下长期施肥对土壤溶解性有机碳(DOC)、溶解性有机氮(DON)含量的影响,为农田土壤碳氮管理提供指导。【方法】收集2000—2019年已发表文献72篇,获得相对独立数据(510组DOC和208组DON),采用整合分析(Meta-analysis)方法定量分析不同利用方式、熟制和土壤pH下施肥对DOC和DON含量的影响。【结果】与不施肥相比,施肥均能显著提高土壤DOC和DON含量,其中施有机肥(单施或配施)的提高幅度(60%和93%)是化肥(13%和29%)的4.6倍和3.2倍。不同利用方式下,施肥能显著提高旱地土壤DOC和DON含量,且旱地施用有机肥提升土壤DOC和DON的幅度显著高于水旱轮作。不同熟制比较,一年一熟下施用有机肥后DOC含量提高85%,显著高于一年两熟(38%);不同pH土壤比较,碱性土壤(pH>7.5)上施用有机肥后DOC和DON含量分别提高了85%和162%,显著高于6.5<pH<7.5的中性土壤(48%和70%)和pH<6.5的酸性土壤(32%和61%)。【结论】施用有机肥(单施或配施)可显著提高DOC和DON含量,但其效果会因利用方式、熟制、土壤pH等的不同有较大差异,因此,有机肥的施用应综合考虑相应的土壤和环境条件。

【Objective】The objectives of this study were to assess the influence of long-term fertilization on the soil dissolved organic carbon(DOC)as well as soil dissolved organic nitrogen(DON)under various use types,cropping systems and soil pH,to give management guidance on how to increase soil carbon and nitrogen in Chinese Cropland.【Method】In current study,72 literatures including effects of long-term fertilization on the contents of DOC and DON in Chinese Cropland from 2000 to 2019 were selected(510 dataset for DOC and 208 dataset for DON).The meta-analysis was used to investigate how the magnitude of the DOC and DON contents response to mineral fertilizer and manure application at three aspects:use types,cropping systems and soil pH.【Result】At national scale,the contents of DOC and DON in the fertilized soils were significantly higher than those in the no fertilized soils(CK).The increments of DOC and DON contents in manure applied soils(60%和93%)were 4.6 and 3.2 times higher than those in the soils with mineral fertilizers(13%and 29%).Under different use types,fertilizer application can significantly increase the contents of DOC and DON in upland soil,and the increments of DOC and DON contents improved by manure in upland soil were higher than those in upland-paddy soil.Furthermore,manure application could increase the content of DOC in mono-cropping(85%)compared with no fertilizer(CK),which was significantly higher than that in double-cropping(38%).For the alkaline soils(pH>7.5),the increments of DOC and DON contents in the treatment with manure amendment(85%and 162%)were higher than those in the neutral(6.5<pH<7.5,48%and 70%)and acidic soils(pH<6.5,32%and 61%)compared with no fertilizer(CK),respectively.【Conclusion】In summary,the application of manure(only manure or combined with mineral fertilizer)could significantly increase the contents of DOC and DON,but the effects varied greatly across various use types,cropping systems,soil pH.Therefore,the appropriate conditions of soil and environment should be taken into account when applying manure.