Research On Ecological Effect Of Different Tillage Methods In Northern ShanXi, China

At present, as the problem of soil wind erosion and cropland desertification becomes very serious in China, the strong sandy storm occurred ,once again arouse people's concern about the issue of controlling sandy storm. People understand that afforestation, planting grasses and developing conservation tillage were the effective measures on reducing winderosion. How to reducing winderosion and improve farmers' income at the same time? The role of conservation tillage should be special pay attention.In the paper, research on occurrence mechanism and control technology of wind erosion in agricultural lands is reviewed. Base on the observed soil moisture ,crop and meteorological data in hunyuan, shanxi province in 2004, the principle of water banlance was used to study water depletion of natural forest, artificial grassland and farmland, water use efficiency, economic benefits and ecological benefits were compared under different land use types. The primary results showed that:In reducing winderosion, fruit trees > Alfalfa land > no-tillage land > tillage land. Results show: conservation tillage, which features more residue cover and less soil disturbance, could remarkably reduce soil loss; residue cover was found to be more efficient for soil conservation.The results show: under low light regimes, No-tillage'photosynthesis increase 35% than Tillage', Sub-tillage' is the same as tillage', Reduce-tillage' increase 8% than Tillage'; While light regimes add, Sub-tillage'photosynthesis increase soon. Under high light regimes, Sub-tillage'photosynthesis and transpiration durnalvaviation is the most.In soil's surface, Tillage's temperature is higher 0.3 ℃ than No-tillage's; But Tillage's temperature is lower 0.4°C than No-tillage's in 5,10cm depth; Tillage's temperature is the same as No-tillage's in May and July, Tillage's temperature is lower 0.6 ℃ than No-tillage's in June in 15,20cm depth.During arid period, soil water storage of different treatments is the same above 1m depth while soil water storage of Sub-tillage and No-tillage increase 31.6% and 28.6% than Tillage'soil water storage; Soil water storage variation of Sub-tillage and No-tillage decrease 54.2%, 58.6% than Tillage' in 2m depth during rainy season; Soil water storage ofSub-tillage increase 5.4mm , No-tillage and Tillage decrease 1.2mm and 4.2mm during stable period.No-tillage'yield is much more 19.3% than Tillage; Water consumption of Sub-tillage and No-tillage is less 33.6 mm, 26.2mm than Tillage; Water use efficiency of Sub-tillage and No-tillage increase 2.8%, 15% than Tillage.Conservation tillage'water content has obviously higher about 60~110% than Alfalfa and woodland, which may lead to desiccation. As the Loess Plateau is subject to high rainfall variability, the prediction of soil water change is more important to make decision on crop sequence in complex agriculture-ecosysterm to minimize production risk and safeguard ecosysterm.