不同水肥条件下夏玉米/冬小麦农田生态系统碳平衡研究  

Carbon Balance in Summer Maize/Winter Wheat Farmland Ecosystem under Different Water and Fertilizer Conditions

作　　者：陈绍民 杨硕欢 张保成 王丽[1] 胡田田[1] CHEN Shaomin;YANG Shuohuan;ZHANG Baocheng;WANG Li;HU Tiantian(Key Laboratory of Agricultural Soil and Water Engineering in Arid and Semiarid Areas,Ministry of Education,Northwest A&F University,Yangling,Shaanxi 712100,China)

机构地区：[1]西北农林科技大学旱区农业水土工程教育部重点实验室,陕西杨凌712100

出　　处：《农业机械学报》2021年第5期229-238,共10页Transactions of the Chinese Society for Agricultural Machinery

基　　金：公益性行业(农业)科研专项(201503124)。

摘　　要：农田生态系统碳平衡取决于农作物固定碳量和土壤异养呼吸排放碳量。为揭示水肥用量对农田生态系统碳平衡的综合影响,设置3个灌水水平:高水、中水和低水(W1、W0.85、W0.7夏玉米季分别为90、76.5、63 mm,冬小麦季分别为140、119、98 mm),4个施氮水平:高氮、中氮、低氮和不施氮(N1、N0.85、N0.7、N0夏玉米季分别为300、255、210、0 kg/hm^(2),冬小麦季分别为210、178.5、147、0 kg/hm^(2)),4个施磷水平:高磷、中磷、低磷和不施磷(P1、P0.85、P0.7和P0夏玉米季分别为90、76.5、63、0 kg/hm^(2),冬小麦季分别为150、127.5、105、0 kg/hm^(2))进行了田间试验。结果表明:不同水肥处理下夏玉米/冬小麦农田生态系统表现为碳汇,夏玉米季净生态系统生产力固碳量(C_(NEP))为6 805~7 233 kg/hm^(2),冬小麦季C_(NEP)为5 842~6 434 kg/hm^(2),夏玉米C_(NEP)高于冬小麦。在高、中、低肥水平下,增加灌水量,夏玉米/冬小麦周年净初级生产力固碳量(C_(NPP))提高2.48%~5.96%,土壤微生物异养呼吸碳释放量(C_(Rm))增加2.15%~15.20%,净生态系统生产力固碳量(C_(NEP))增加1.16%~6.47%。在高、中、低供水水平下,增加施肥量,夏玉米/冬小麦周年C_(NPP)增加2.95%~3.43%,土壤C_(Rm)增加5.23%~18.67%,C_(NEP)增加0.93%~2.79%,C_(NEP)增加比例与供水水平呈负相关。在低水条件下,氮磷肥配施处理夏玉米/冬小麦农田周年C_(NEP)较单施氮、磷肥分别增加4.86%、7.34%,且氮磷肥交互作用显著(P <0.05),水肥供应水平相差15%时对冬小麦农田C_(NEP)有显著的正交互作用。氮磷肥配施、水肥协调供应均有助于促进夏玉米/冬小麦农田生态系统的净碳输入,在节水节肥原则下,夏玉米和冬小麦分别在W0.85N0.85P0.85和W0.7N0.85P0.85水肥供应条件下有利于增加农田C_(NEP)。The carbon balance of the farmland ecosystem depends on the fixed carbon content of crops and carbon emissions from soil heterotrophic respiration.In order to reveal the comprehensive effects of water and fertilizer levels on carbon balance in farmland ecosystems,a field experiment of summer maize/winter wheat rotation cycle in Yangling District of Shaanxi Province was conducted during 2015—2016.Three irrigation levels:high,medium and low(W1,W0.85 and W0.7 meant 90 mm,76.5 mm and 63 mm in summer maize season and 140 mm,119 mm and 98 mm in winter wheat season),four nitrogen fertilizer levels:high,medium,low and no nitrogen(N1,N0.85,N0.7 and N0 meant N 300 kg/hm^(2),255 kg/hm^(2),210 kg/hm^(2)and 0 kg/hm^(2)in summer maize season and 210 kg/hm^(2),178.5 kg/hm^(2),147 kg/hm^(2)and 0 kg/hm^(2)in winter wheat season)and four phosphate fertilizer levels:high,medium,low and no phosphate(P1,P0.85,P0.7 and P0 meant P 2 O 590 kg/hm^(2),76.5 kg/hm^(2),63 kg/hm^(2)and 0 kg/hm^(2)in summer maize season and 150 kg/hm^(2),127.5 kg/hm^(2),105 kg/hm^(2)and 0 kg/hm^(2)in winter wheat season)were designed.CO 2 flux measurements were performed,using the static opaque chamber and chromatography method,and aboveground biomass and yield were measured.The net primary productivity carbon fixation(C NEP)and soil microorganisms heterotrophic respiratory carbon release(C Rm)were also calculated to evaluate net ecosystem productivity carbon fixation(C NEP).The results showed that the summer maize/winter wheat farmland ecosystem under different water and fertilizer treatments performed as carbon sink.The range of C NEP in summer maize and winter wheat seasons were 6805~7233 kg/hm^(2)and 5842~6434 kg/hm^(2),respectively.At high,medium and low fertilizer levels,with the increase of irrigation amount,the C NPP of summer maize/winter wheat rotation cycle was increased by 2.48%~5.96%,the C Rm of soil was increased by 2.15%~15.20%,and the C NEP was increased by 1.16%~6.47%,respectively.Under the high,medium and low water supply levels,with the in

关 键 词：夏玉米/冬小麦 灌水量 施肥量 水肥交互作用 碳平衡 

分 类 号：S181[农业科学—农业基础科学] S365