中国生态农业学报2016，Vol.24Issue(4)：478-488,11.DOI:10.13930/j.cnki.cjea.150953
减量施氮与间作大豆对蔗田碳平衡特征的影响*
Effectsofreducednitrogenapplicationandsugarcane-soybean intercroppingoncarbonbalanceinsugarcanefields
摘要
Abstract
Intercropping has an outstandingly long history in China. Studies have reported several advantages of cereal- legume intercropping systems, including increased yields, land use efficiency, natural resources utilization, and pest anddiseasecontrol.Thishasahugepotentialtosignificantlycontributetothesustainabilityofmodernagriculture.Ascerealcrop,sugarcaneisamajoreconomiccropusedintheproductionofsugarinChina.Itswide-rowplantingspaceandslowgrowthrateduring initial growth stage provide the required niche of space and resources for intercropping. However, long-termmono-cropping of sugarcane along with the overuse of nitrogen fertilizer has induced severe nitrous pollution in theenvironmentandhighcostofagriculturalproductioninSouthChina.Sugarcane-soybeanintercroppingcanreducenitrogenapplication while maintaining high crop yield, in turn reducing the overall cost of farming, enriching soil fertility andenhancing soil carbon sequestration in the field. However, few studies have investigated carbon balance under sugarcaneintercropping and carbon sequestration in sugarcane intercropping fields. The objective of this study was to determine theeffectsofsugarcaneandsoybeanintercroppingunderreducednitrogenfertilizeronsoilcarbonbalance.Thisstudywillfurtherstrengthenthescientificbasisfortheuptakeandutilizationofsoilnutrientandtherelationshipsamongnutritionutilizationandenvironmentalfactorsunderintercroppingsystems.Tothatend,afieldexperimentwasconductedin2012–2013inSouthChina Agriculture University. The study analyzed carbon balance and sequestration in farmlands in sugarcane-soybeanintercropping systems with crop line ratio of 1︰1, sugarcane-soybean intercropping systems with crop line ratio of 1︰2,monocroppedsugarcane(MS)undertwonitrogenlevels(N1,300kg·hm-2andN2,525kg·hm-2)andmonocroppedsoybeanunderzeronitrogensupplyduringcropgrowthseason.Carbonbalanceandsequestrationinfarmlandsoilswereinvestigatedinthis study using Input-Output Analysis, where carbon input and output were quantified for crop growth period in order todeterminetheintensityofcarbonsink.Theresultsshowedthatcarboninputundersugarcane-soybean(1︰2)intercroppingsystemwassignificantlyhigherthanthatundermonoculturesugarcaneandsugarcane-soybean(1︰1)intercroppingundertwonitrogenapplicationlevels.Comparedwithsugarcane-soybean(1︰1)intercroppingandmonoculturesugarcane,carbonoutputunder sugarcane-soybean (1︰2) intercropping was significantly decreased with reducing nitrogen application in 2012,althoughtherewasnosignificantdifferencein2013.Afterharvestingsugarcane,soilcarbonstorageundersugarcane-soybeanintercropping systems with reduced nitrogen application was significantly higher than that under monoculture sugarcane.Carbonbudgetanalysisforsugarcane-soybeanintercroppingsystemsshowedthatsugarcane-soybean(1︰2)intercroppingwasagoodnetcarbonsinkwithhighcarbonfixationof2956.35kg·hm-2in2012,and872.59kg·hm-2in2013underreducednitrogenapplicationconditions.Itwasnotedthatsugarcane-soybean(1︰2)intercroppingwithreducednitrogenapplicationhadbettercarbonstoragepotential.Inaddition,thevalueoflandequivalentratio(LER)ofsugarcane-soybeanintercroppingsystemsexceeded1.0in2012and2013.AlsoLERofsugarcane-soybean(1︰2)intercroppingsystemwithreducednitrogenapplication was higher than 1.0. In conclusion, sugarcane-soybean intercropping system (1︰2) with reduced nitrogenapplicationwasafeasibleproductionmodeforthesustainabilityofmodernagriculture.关键词
甘蔗/大豆间作/减量施氮/碳输入/碳输出/碳平衡/农田固碳Key words
Sugarcane-soybeanintercropping/Reducednitrogenapplication/Carboninput/Carbonoutput/Carbonbalance/Soilcarbonsequestration分类
农业科技引用本文复制引用
管奥湄,章莹,刘宇,罗莎莎,王建武..减量施氮与间作大豆对蔗田碳平衡特征的影响*[J].中国生态农业学报,2016,24(4):478-488,11.基金项目
国家重大基础研究计划(973计划)项目(2011CB100400)、国家科技支撑计划项目(2012BAD14B16-04)和广东省科技计划项目(2012A020100003)资助* ThestudywassupportedbytheNationalProgramonKeyBasicResearchProjectofChina(973Program,No.2011CB100400),theNationalKeyTechnologyR&DProgramofChina(No.2012BAD14B16-04)andtheScience-technologyProjectofGuangdongProvince(No.2012A020100003). （973计划）
