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以夏玉米和冬小麦两季作物作为整体来研究保护性耕作对玉米季各生育期土壤微生物生物量碳(SMB-C)和微生物生物量氮(SMB-N)的影响。设置5种耕作处理,分别为小麦、玉米每年均翻耕(CTWT),玉米免耕+小麦每年翻耕(CNTWT),玉米免耕+小麦每2年翻耕(CNTW2T),玉米免耕+小麦每4年翻耕(CNTW4T),小麦、玉米每年均免耕(CNTWNT),所有处理在作物收获后移出地上部分全部秸秆。研究结果表明:在玉米生育期内,各处理土壤SMB-C、SMB-N随作物的生育期表现出先上升,在玉米抽雄期达到最大,然后开始下降,在乳熟期出现低谷,随后缓慢回升的趋势。而在整个生育期内各处理土壤SMB-C、SMB-N表现为CNTWNT>CTWT>CNTW2T>CNTWT。由于SMB-C、SMB-N可作为评价土壤质量的生物学指标,因此可以认为,玉米-小麦轮作保护性耕作体系下,免耕较传统耕作可以提高耕地土壤质量,增加土壤肥力。
The effects of conservation tillage on soil microbial biomass carbon (SMB-C) and microbial biomass nitrogen (SMB-N) during the whole growing season were studied using summer maize and winter wheat as the whole crop. Five kinds of tillage treatments were set up, including CTWT, CNTWT, CNTW2T, CTL + wheat Every 4 years of tillage (CNTW4T), wheat and corn are tillage-free (CNTWNT) every year and all treatments are removed from the above ground straw after harvesting. The results showed that SMB-C and SMB-N of soils showed the first increase during the growth period of maize and reached the maximum during tasseling stage of maize, then began to decline and then declined during milking stage and then slowly rose the trend of. Soil SMB-C and SMB-N showed CNTWNT> CTWT> CNTW2T> CNTWT during the whole growth period. Since SMB-C and SMB-N can be used as biological indicators to evaluate soil quality, it can be considered that no-till under traditional tillage system can increase soil quality and increase soil fertility.