保护性耕作对黄土高原玉米-小麦-大豆轮作系统产量及表层土壤碳管理指数的影响

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。

Effects of conservation tillage on crop yield and carbon pool management index on top soil within a maize-wheat-soy rotation system in the Loess Plateau

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 c...