Effects Of Conservation Tillage Managements On Oat Drought Resistant, Seedling Keeping And Yield Increasing

Qingshuihe County in Inner Mongolia is a typical dry farming hilly and gully area of the Loess Plateau. Due to drought, water shortage and long tradition of plowing, leading to the difficulty of emergence and seedling keeping, low and unstable yield. Conservation tillage can keep moisture, keep seedling and increase production. This paper was conducted with oat cultivar Bayou1as the test material in Qingshuihe County, Inner Mongolia in2011-2013. Studying the effects of different tillage managements (NT, SA, SS, PA and SA) on correlated characters at oat seedling stage, soil physicochemical and biological properties and yield to determine the effects of drought resistant, seedling keeping and yield increasing of conservation tillage and provide a reliable theoretical basis and technical support for production and efficiency improvement of rainfed farmland in the region. The results showed as follows:1NT compared with other treatments can significantly improve the emergence rate of oats, NT, SA and SS were conducive to the growth of oat seedlings, improve oat fresh and dry weight aboveground, root activity and SPAD values. The emergence rate of NT increased3.2and6.9than PS and PA respectively in2years. Plant fresh weight increased3.56%-19.54%, plant dry weight increased4.07%-16.37%, root activity increased2.82%-19.95%, SPAD value increased0.91%-6.30%.2NT, SA and SS can improve soil water conditions during the crop growth, improve soil water storage and soil stable infiltration rate, enhanced soil water retention capacity and provided a guarantee for a good crop growth; NT, SA and SS can also improve soil aggregate distribution structure, promote the formation of>2mm diameter large soil aggregates and increase the content of>0.25mm soil aggregates. In0-10cm soil layer,>0.25mm soil aggregates of each treatment increased19.50%-38.14%than PS and PA in2years. Subsoiling can significantly reduce soil bulk density and increase soil porosity before sowing. Subsoiling also had a certain effect in decreasing soil bulk density in oat harvest time.3NT, SA and SS can increase the soil organic matter, Alkeline-N, available P and available K content in harvest time. In2years, the average soil organic matter content of0-10cm layer of NT, SS and SA increased by5.24%-9.44%than PS and PA, Alkeline-N increased by2.30%-7.24%, available P increased by2.56%-7.19%, available K increased by7.74%-10.16%. 4NT, SA and SS can improve soil biological characteristics to a certain extent, improve the soil microbial biomass and soil enzyme activity. At the heading stage of0-40cm soil layer, compared with PS, the microbial biomass C content of NT, SA and SS increased by2.45%-9.80%on average, microbial biomass N content increased by5.34%-17.91%, soil catalase activity increased by4.41%-14.46%, soil invertase activity increased by4.66%-15.38%, urease activity increased by5.05%-16.09%.5NT, SA and SS can significantly improve the number of spikes, grain number per spike and1000-grain weight, improve grain yield and water use efficiency in oat growing period. In2years, water use efficiency of each treatment increased by1.30%-17.62%, the grain yield increased by3.83%-17.98%, output increased by3.80%-17.86%; Economic benefit increased by465.35yuan·hm-2-1092.75yuan·hm-2.Considering the oat seedling related indicators, soil traits, yield and economic benefit, NT, SA and SS showed better, and SA was the best among those treatments.