作　　者： ; ; ; ; ; ;

机构地区： 西北农林科技大学

出　　处： 《中国农业科学》 2012年第8期1513-1520,共8页

摘　　要： 【目的】探明秸秆还田对土壤团聚体的影响,为宁南半干旱区作物生产及土壤培肥制度的建立提供参考。【方法】本研究通过4年秸秆还田定位试验,设置了不同秸秆粉碎还田量处理:谷子秸秆还田量为3 000 kg.hm-2(低,L)、6 000 kg.hm-2(中,M)、9 000 kg.hm-2(高,H),玉米秸秆还田量为4 500 kg.hm-2(低,L)、9 000 kg.hm-2(中,M)、13 500 kg.hm-2(高,H),对照为秸秆不还田。对不同处理条件下干筛和湿筛下各团聚体指标进行分析。【结果】各秸秆还田处理干筛下0—40 cm土层>0.25 mm团聚体含量(DR0.25)、平均重量直径(mean weight diameter,DMWD)和几何平均直径(geometric mean diameter,DGMD)均显著高于CK处理,各还田处理的分形维数均显著低于CK;湿筛法分析表明,供试土壤中团聚体以机械稳定性团聚体为主,随秸秆还田量的增加,0—40 cm土层水稳性团聚体的平均重量直径(WMWD)、几何平均直径(WGMD)和分形维数的顺序均为:H,M处理>L处理>CK;各处理土壤团聚体破坏率(PAD)和不稳定团粒指数(ELT)在0—40 cm土层内均表现出近似"Z"字形趋势,且CK显著高于各还田处理(P<0.05)。【结论】在宁南半干旱区采用秸秆还田对提高土壤团聚体含量具有明显作用。 【Objective】 A field experiment was conducted to determine the effects of straw returning systems on soil aggregate of millet or corn under different straw returning supplies.in order to provide a theoretical basis for establishment of a fertilization system and crop management for semi-arid areas of southern Ningxia.【Method】The effects of straw returning,taking no straw returning as the control,on soil aggregate indexes by dry and wet sieving under different straw returning treatments（3 000 kg·hm^-2（L）,6 000 kg·hm^-2（M） and 9 000 kg·hm^-2（H） of millet straw and 4 500 kg·hm^-2（L）,9 000 kg·hm^-2（M） and 13 500 kg·hm^-2（H） of corn straw） were studied for four years（2007-2010）.【Result】After the millet harvest（2010）,dry sieving results showed that DR0.25,DMWD and DGMD of straw returning treatments higher than CK,the fractal dimension lower than CK in 0-40 cm soil layer,significantly.Wet sieving results showed that straw returning treatments had different effects on the WGMD,WMWD and fractal dimension of 0-40 cm soil layer,which followed the order from high to low： H,MLCK.There is a ＇Z＇ tendency of PAD and ELT in 0-40 cm soil layer for each treatment,and CK is significantly higher than straw returning treatments（P〈0.05）.【Conclusion】 The content of soil aggregates could be improved efficiently by using straw returning technology in semi-arid areas of Southern Ningxia.

关 键 词： 秸秆还田 土壤团聚体 宁南半干旱区

领　　域： [农业科学] [农业科学]