草业学报2017，Vol.26Issue(1)：13-22,10.DOI:10.11686/cyxb2016089
保护性耕作下蚕豆田土壤呼吸及碳平衡特性
Soil respiration and carbon balance in fava bean farmland under conservation tillage
摘要
Abstract
Soil respiration is an important process in carbon cycling.This study investigated effects of two till-age practices (ridge tillage and traditional tillage)and straw mulching at 0,3750,or 7500 kg straw dry matter/ha on soil respiration of fava bean farmland.Six treatments applied were:traditional tillage without straw mulching (T),ridge tillage without straw mulching (R),traditional tillage+straw mulching at 3750 kg/ha (TS1 ),ridge tillage+straw mulching at 3750 kg/ha (RS1 ),traditional tillage+straw mulching at 7500 kg/ha (TS2 ),and ridge tillage+straw mulching at 7500 kg/ha (RS2 ).Soil respiration properties and carbon balance in dry-cropped farmland with a triple intercropping system of fava bean,maize,and sweet tomato were evalua-ted during the crop growth period,in a region of southwest China known as the purple hilly region.This study identified seasonal changes in soil respiration rate reflecting crop growth,with a peak in the middle of the fava bean growth cycle,and with a range from 0.885 -10.213 μmol/(m2 ·s)in cropped soils,respectively.The soil respiration rates of the different treatments ranked TS2 >RS2 >RS1 >TS1 >T>R [4.096,3.780,3.441, 3.104,2.850,2.439 μmol/(m2 ·s),respectively].Ridge tillage reduced soil respiration in fava bean farm-land,whereas straw mulching treatment resulted in increased respiration corresponding to straw mulching lev-els.In soil planted with fava bean,the respiration rate at different crop growth stages ranked ripening<seed-ling<seed filling <branching< flowering and podding.Soil respiration during flowering,filling and podding stages contributed 50% of the total soil respiration.The contribution of root respiration to total soil respiration was 49.12% (range 37.02% - 60.64%)when measured by a root biomass regression equation,but was 38.62% (range 19.49%-52.3%)when measured by root exclusion.The farmland system sequestered carbon during the life cycle of the fava bean crop with a net carbon sink ranging from 857.26 to 2236.25 kg C/(ha·yr).The treatments RS2 ,TS2 ,RS1 ,TS1 ,R increased carbon sequestration by 160.86%,101.44%, 30.78%,47.63% and 110.41%,respectively (P <0.05),compared to the treatment T.This study indicated that ridge tillage and straw mulching conservation improved carbon sequestration in a fava bean farmland eco-system,and the best treatment was RS2 (ridge tillage+straw mulching at 7500 kg/ha).关键词
土壤呼吸/根系呼吸/碳平衡/蚕豆/保护性耕作Key words
soil respiration/root respiration/carbon balance/fava bean/conservation tillage引用本文复制引用
熊瑛,王龙昌,赵琳璐,杜娟,张赛,周泉..保护性耕作下蚕豆田土壤呼吸及碳平衡特性[J].草业学报,2017,26(1):13-22,10.基金项目
国家自然科学基金项目（31271673）和公益性行业（农业）科研专项（201503127）资助。 （）
