旱地农田不同耕作系统的能量/碳平衡  

Coupled energy and carbon balance analysis under dryland tillage systems

作　　者：王小彬[1,2] 王燕[1] 代快[1] 武雪萍[1,2] 赵全胜[1] 张丁辰[1] 冯宗会[1] 蔡典雄[1,2] 

机构地区：[1]中国农业科学院农业资源与农业区划研究所农业部植物营养与养分循环重点实验室,北京100081 [2]农业部旱作节水农业重点实验室,北京100081

出　　处：《生态学报》2011年第16期4638-4652,共15页Acta Ecologica Sinica

基　　金：国家重点基础研究发展"973"计划项目(2011CB100501/2007CB109305);国家自然科学基金(40571151);国家"863"计划项目(2006AA100220)资助

摘　　要：加强农田土壤保持耕作管理,科学认识和调控农田耕作系统能流碳流,提高农业生态系统固碳减排能力,对于减缓农业对全球温室效应的贡献具有重要意义。以北方半湿润偏旱区山西寿阳旱作春玉米土壤保持耕作试验研究为基础,利用田间定位观测数据、辅助能投入参数,土壤呼吸田间原位测定,以及农业生态系统能量/碳平衡分析及碳循环过程模拟方法,综合分析和比较不同耕作(CT传统、RT少耕和NT免耕)系统能量/碳平衡及能-碳关联影响。与CT比较,采用RT和NT措施下工业能耗CO2-C损失降低约4%—12%(相当11—35 kg CO2-C.hm-.2a-1)。在RT和NT系统下耗能系数可降低约6%—10%,能量生产效率可提高约7%—12%。2006—2007年由田间原位测定土壤呼吸CO2-C释放通量估算,在玉米休闲期(尤其是秋耕处理后),NT条件下土壤呼吸速率一般为最低(NT<CT<RT),而在玉米生长高峰期为最高。玉米休闲期土壤呼吸通量(kg CO2-C.hm-.2a-1)平均为:NT(540±30)<CT(619±20)<RT(873±137),NT较CT降低约13%。玉米生育期土壤呼吸通量(kg CO2-C.hm-.2a-1)平均为:CT(1368±355)<RT(1468±387)和NT(1465±410),RT和NT较CT提高约7%。比较不同耕作处理全年土壤呼吸总量(kg CO2-C.hm-.2a-1)平均为:RT(2342±524)>NT(2005±380)>CT(1987±375)。不同耕作下的玉米籽粒产量与生育期土壤呼吸通量趋势基本吻合,如2006-2007年玉米产量(kg.hm-.2a-1)平均为,RT(5614±268)>NT(5533±564)>CT(5487±278)。玉米籽粒产量与生育期土壤呼吸通量之间呈密切相关(R2=0.88)。本研究结果得出,RT和NT对农田耕作系统的影响呈碳汇效应,且一般为NT>RT;而CT处理表现为碳源。RT和NT通过增加土壤碳投入是维持和提高土壤有机碳的有效途径。Scientific regulation of both energy and carbon flows under tillage system with soil conservation tillage practices is of great significance for saving energy input in farmland,mitigating greenhouse gas emission to the atmosphere,and increasing carbon sequestration potential in soils.Based on the field experimental studies on conservation tillage in dryland maize cropping systems,located in Shouyang Dryland Farming Station in Shanxi province of China,impacts of different tillage systems（including conventional tillage（CT）,reduced-tillage（RT）,and no-till（NT） practice） on coupled energy /carbon balance were integrally studied.through field observations,embodied energy input parameter determinations,soil respiration measurements,carbon dynamic processe simulations,and energy /carbon balance estimations in dryland agro-ecosystems.Compared with CT,conservation tillage（RT and NT） could increase carbon input（about 1.6 tC·hm-2） with increasing stover return and root stubble biomass in the soils,but reduce carbon losses by stover burning /or removal（about 1.6 tC·hm-2） and by soil erosion（about 1.2—1.6 tC·hm-2）.The energy inputs（MJ·hm-2） were in the order： CT（13829） RT（13289） NT（12434）,which was similar to the order for carbon emissions（kgC·hm-2）： CT（283） RT（272） NT（248）.The embodied energy consumption was reduce by about 4%—12%（equivalent to 11—35 kg CO2-C·hm-2·a-1） with NT and RT practices,as compared to the CT practice.The coefficiency of energy consumption was decrease by about 6%—10% and the coefficiency of energy production increase by 7%—12% under conservation tillage systems,as compared to the CT practice.The results also showed that the rates of soil organic carbon sequestration（kg C·hm-2·a-1） tended to increase from-104 with CT to 144—149 with NT and RT.The field measurements during periods 2006—2007 showed that the mean soil respiration rates（kg CO2-C·hm-2·a-1） with NT were generally lowest（-13%） during th

关 键 词：土壤保持耕作 农业生态系统 能量平衡 碳平衡 

分 类 号：S181[农业科学—农业基础科学]