Evaluation Of Ecological And Economical Suitability Of Conservation Tillage In The Semi-arid Areas Of The Loess Plateau

Basing on the research of conservation tillage experiment in the semi-areas of the Loess plateau from 2001 to 2005, we compared and evaluated the economical and ecological suitability of the conventional tillage methods and 5 kinds of conservation tillage methods. The results showed that the economical and ecological suitability of NTS is the best in several tillage methods.1 The ecological suitability of the conservation tillage(1) The different of the tillage method has the different influence to the surface of soil bulk. Compared with T, the treatment NTS can decrease the surface of soil bulk. The reason of the NTS can decrease the surface of soil bulk is that the surface of land is covered with the straw and the rotten straw can increase the soil organic matter which leaded to the soil bulk decrease. The surface of soil bulk of NTP is higher than the T, the reason of the NTP can increase the soil bulk is that after the successive 4-5 years no-tillage increase the soil density and the plastic film also leads to the soil become harder(2)For the top soil pores distribution, different rotation sequence has the different influence. In Pea→Wheat rotation sequence >30μm pores content was higher and﹤30μm pores content was lower than Wheat→Pea rotation sequence . Different tillage methods have the different influence to the soil pore distribution .Compared with other Tillage methods ,TS,NTS can increase the soil pores content .(3) Both in Pea→Wheat and Wheat→Pea rotation sequences, Soil saturated hydraulic conductivity was significantly higher in NTS treatment than any other treatment. Therefore, the treatment NTS has the best hydraulic in the several treatments, which can save more water for the soil and support more water for the crop growing.(4) The soil organic matter is an important index for the soil fertilizer .The more soil organic matter, the more soil fertilize. Both in Pea→Wheat and Wheat→Pea rotation sequences, total organic carbon was significantly higher in NTS and TS treatments than in T and NT treatments, the main reason is that straw lead to total organic carbon of top soil increase in TS and NTS treatments.(5) After crop harvest and before tillage, For the soil hardness, Although the treatments T,TS,TP were tilled every year, NT,NTS,NTP were not tilled, the difference of every...