摘要
耕作措施是影响稻田生态系统净碳汇效应和经济收益的关键因素。为探明南方双季稻区不同耕作模式下稻田耕层土壤(0-20 cm)固碳速率和土壤碳密度、年碳汇平衡和经济收益的变化特征,开展紫云英(Astragalus sinicus L.)-双季稻大田定位试验,设双季水稻翻耕+秸秆还田(CT)、双季水稻旋耕+秸秆还田(RT)、双季水稻免耕+秸秆还田(NT)、双季水稻旋耕+秸秆不还田(RTO,对照)4种耕作处理,系统分析了不同耕作方式对稻田耕层土壤固碳速率和土壤碳密度、年碳汇平衡和经济收益的影响。研究结果表明,各处理稻田耕层土壤的固碳速率变化范围为2.98-3.43 t·hm^-2·a-1,耕层土壤碳密度为29.77-34.33 t·hm^-2,其大小顺序均表现为CT>RT>NT>RTO。不同耕作处理稻田生态系统作物的净碳固定变化范围为5.27-7.43 t·hm^-2·a-1,其大小顺序表现为CT>RT>NT>RTO;CT和RT处理土壤的净碳汇量分别比NT处理增加40.26%和3.90%。不同处理稻田生态系统物质投入的碳成本为0.03-0.85 t·hm^-2·a-1,年经济收益为7.11-8.81×103 CNY·hm^-2·a-1,稻田生态系统经济效益大小顺序表现为CT>RT>NT>RTO。总之,翻耕、旋耕结合秸秆还田处理均有利于提高双季稻田耕层土壤的固碳速率、碳汇效应和经济收益,是增加耕层土壤有机碳库贮量的有效措施。
Annual net carbon(C) sink and economic benefit of paddy ecosystem were affected by different tillage managements. In order to explore the effects of different tillage treatments on soil organic carbon sequestration rate, soil organic carbon density of plough layer in paddy field, annual C balance, and economic benefit of paddy ecosystem under double-cropping rice field in southern China, a fixed location field experiment were conducted using Chinese milk vetch(Astragalus sinicus L.) and double-cropping rice system with four tillage treatments including conventional tillage with residue incorporation(CT), rotary tillage with residue incorporation(RT), no-tillage with residue retention(NT), and rotary tillage with residue removed as control(RTO). Therefore, the effects of different tillage treatments on soil organic carbon sequestration rate, soil organic carbon density of plough layer in paddy field, annual C balance, and economic benefit of paddy ecosystem under double-cropping rice field were studied in the present paper. The results showed that the range of soil organic carbon sequestration rate of plough layer in paddy field with different tillage treatments was from 2.98 to 3.43 t·hm^-2·a-1, and the range of soil organic carbon density of plough layer in paddy field with different tillage treatments was from 29.77 to 34.33 t·hm^-2. And the soil organic carbon sequestration rate and soil organic carbon density of plough layer in paddy field with different tillage treatments followed the order of CT>RT>NT>RTO. Meanwhile, the results indicated that the range of net C sequestration of crop under paddy ecosystem was from 5.27 to 7.43 t·hm^-2·a-1, and the net C sequestration of crop under paddy ecosystem with different treatments followed the order of CT>RT>NT>RTO. Compared with NT treatment, the net C sink with CT and RT treatments increased 40.26% and 3.90%, respectively. The range of C cost of material and management input of paddy ecosystem with different tillage treatments was from 0.03 to 0.85 t·hm^-2·a-1. And the range of annual economic benefit with different tillage treatments was from 7.11 to 8.81×103 CNY·hm^-2·a-1. The economic benefits of paddy ecosystem with different tillage treatments followed the order of CT>RT>NT>RTO. The results indicated that the soil organic carbon sequestration rate, C sink and annual economic benefit increased under combined application of conventional tillage and rotary tillage with residue incorporation conditions. As a result, combined application of conventional tillage and rotary tillage with residue incorporation is an effective practice to increase soil organic carbon storage in paddy filed.
作者
唐海明
李超
肖小平
潘孝晨
程凯凯
董春华
石丽红
罗尊长
TANG Haiming;LI Chao;XIAO Xiaoping;PAN Xiaochen;CHENG Kaikai;DONG Chunhua;SHI Lihong;LOU Zunchang(Hunan Soil and Fertilizer Institute,Changsha 410125,China)
出处
《生态环境学报》
CSCD
北大核心
2020年第2期215-222,共8页
Ecology and Environmental Sciences
基金
湖南省农业科技创新资金项目(2019LS03-01)
国家自然科学基金项目(31872851)。
关键词
水稻
耕作
生态系统
碳汇
经济收益
rice
soil tillage
ecosystem
carbon sink
economic benefit
