作　　者： ; ; ; ; ; ; ; (李光棣）;

机构地区： 兰州大学草地农业科技学院农业部草地农业生态系统学重点开放实验室

出　　处： 《草业学报》 2010年第1期75-82,共8页

摘　　要： 在陇东黄土高原雨养农业区,以传统耕作(t)为对照,研究了3种保护性耕作:耕作+秸秆覆盖(ts)、免耕(nt)、免耕+秸秆覆盖(nts)对玉米-大豆-小麦轮作系统产量和土壤全氮、全碳、有机碳,易氧化有机碳及碳库管理指数的影响。结果表明,从2001至2007年,10茬作物的总产量在ts、nts处理下分别比t提高3.63和1.62t/hm2,而nt处理则比t处理显著降低2.48 t/hm2。7年后,tt、s、nt和nts处理表层土壤全氮含量分别提高15.4%,30.2%,16.2%和49.5%。总有机碳含量相应提高2.5%,18.7%,11.7%和74.0%,易氧化有机碳含量在ts,nt和nts处理下分别比t处理提高16.0%,16.2%和38.1%;土壤碳氮比在tt、s、nt和nts处理下较之7年前分别降低了11.41%,8.54%,3.91%和2.72%,ts、nt和nts处理下碳库管理指数分别比t处理提高12.6%,20.1%和46.6%,说明秸秆覆盖+免耕均有利于提高该轮作系统中土壤有机碳含量并改善碳库质量。 The effects of conventional tillage （t）, conventional tillage with stubble retention （ts）, no-tillage （nt）, and no-tillage with stubble retention （nts） treatment on crop yield,soil total nitrogen and carbon, total organic carbon, oxdizible organic carbon, and carbon pool management index （CPMI） were investigated within a maize-wheat-soy rotation system in the western Loess Plateau. Total crop yield for ten harvests during the years 2001 to 2007 under ts and nts treatments increased by 3.63 and 1.62 g/kg compared with conventional tillage, but decreased by 2.48 g/kg on the nt treatment. Total nitrogen contents under nts treatment were 15.4%, 30.2% and 16.2% higher than t, ts and nt treatments. Total carbon under nts treatment was signifi- cantly increased by 2.04 g/kg and total organic carbon were 2.50, t. 56 and 1.70 g/kg higher than under t, ts and nt treatment, respectively. Easily oxdized organic carbon under nts was 2. 13 g/kg higher than under t treatment. TN/TC decreased by 12.75%,15.97%,6.87% and 24. 16% under t, ts, nt and nts treatments. The CPMI under ts, nt and nts were 12.6%,20.1% and 46.6% higher than under t, both stubble retention and no-till were beneficial to increasing the soil organic carbon content and improving the quality of the carbon pool.

关 键 词： 秸秆还田 免耕 有机碳 易氧化有机碳 碳氮比

领　　域： [农业科学] [农业科学] [农业科学] [农业科学]