Experimental Study Of Conservation Till Age In Thenorth Of Mu Us Sandy Land

In recent years, study about wind-induced desertification, which focused on wind erosion control on farmland in north China, got more and more concern due to the dust storm occurred frequently. Some research indicted that the farmland is one of main sources of wind erosion and dust storm. And it is also the weakness links of controlling wind erosion in our country. So, the farmland has been become the main research object and frontiers for controlling wind erosion. The sandy area in the north of Jingbian County is farming-pastoral interlaced zone, where ecological environment is fragile. Furthermore, traditional tillage makes no cover on soil in winter and spring, which enhances soil drying and wind erosion. So, using conservational tillage technology instead of traditional tillage to get high yield and control wind erosion is an effective way to develop ecological agriculture, control desertification, realize sustainable agriculture development, and improve local ecological environment.This paper was based on the survey of climate and soil nutrients changes in the past 20 years in the north windy desert area, Jingbian County. Field observation was conducted at Yangqiaopan Demonstration Farm, Jingbian Agriculture Bureau. Four tillage measurements were investigated: no tillage, residue mulching, film mulching, and traditional tillage for corn. Based on successful introduction of winter wheat, investigation of no tillage, film mulching, and traditional tillage for winter wheat were conducted. Protection effects against wind of different tillage measurements were tested in wind tunnel. Combined the field observation, wind tunnel simulation, and statistics methods, the soil characteristics, water and fertilizer using efficiency, economy profits, and wind control benefit under conservational tillage were systematically investigated. Main results lie below:(1) Strong wind, dry and cold weather often occurred simultaneously in study area, the long term average climate erosion index here is 92.8.The potential wind erosion danger in this area is high. Compared the soil nutrient at two different periods of 1983 and 2003 , it is proved that the proportion of soil fertilizer of Class1 and Class2 decreased 1-2%, Class5 and Class6 increased 5-7%. So, we can see that wind erosion is serious in the study site.(2) Corn conservational tillage improved soil characteristics, water and fertilizer using efficiency, and economy profits.Soil temperature under film mulching, no tillage, and residue mulching was not sensitive to air temperature, and relatively stable throughout the entire crop growing season. But soil temperature under traditional tillage was very sensitive to air temperature. Soil bulk density Compared to traditional tillage, no tillage and residue mulching reduced soil bulk density of 0-20 cm layer, and film mulching increased it. But, no tillage and residue mulching increased bulk density of 20-40 cm layer. The soil water content in 0-60 layer under film mulching, residue mulching, and no tillage were 10.88 mm, 6.26 mm, and 5.08 mm higher than traditional tillage, respectively. No tillage increased the soil nutrients stratification ratio. Organic matter, total N, and available K increased with cultivation time under all tillage measurements, and increased faster under no tillage. Available N and total P decreased with cultivation time, slower under no tillage. WUE under no tillage, residue mulching, and film mulching were 13.3%, 8%, and 22.0% higher than traditional tillage, respectively; N, P fertilizer using efficiency were 61%, 23%, and 60% higher, respectively; crop yield were 4.44%, 13.14%, and 19.26% higher, respectively. Economy profits were according to this sequence: no tillage>residue mulching>traditional tillage>film mulching. Though introduction experiment proved that winter wheat can be planted in this area. At emergence and wintering periods, soil temperature under film mulching and no tillage were higher than traditional tillage. Compared to traditional tillage, no tillage reduced soil bulk density of 0-20 cm layer, but increased it in 20-40 cm layer, film mulching increased bulk density of upper layer. Soil water content under film mulching and no tillage were both higher than traditional tillage. Organic matter, total N, and available K under no tillage and film mulching increased with cultivation time, and increased faster than traditional tillage. Available N and total P had a decreased trend, but no tillage and film mulching lowered the decrease. WUE and N, P fertilizer using efficiency were highest under film mulching, r no tillage were middle, and traditional tillage were lowest. The yield was according this sequence: film mulching>no tillage>traditional tillage. The ratio of output to investment followed: no tillage>film mulching>traditional tillage.(3) Wind Tunnel wind tunnel simulation testing proved that conservational tillage obviously increased surface roughness and threshold velocity. Surface roughness of winter wheat was the highest, then no tillage and film mulching, lowest under traditional tillage. Accordingly, threshold velocity followed: winter wheat>film mulching>no tillage>traditional tillage. Conservational tillage decreased wind erosion rate on farmland. Under the same wind velocity, the wind erosion rate under traditional tillage was obviously higher than other three conservational tillage measurements. Wind erosion rate followed: traditional tillage >film mulching >no tillage>winter wheat.(4) Established the comprehensive evaluation index system which include soil fertilizer index and economic benefits index and wind reduction index. Then evaluated the comprehensive benefit of different tillage methods. Comprehensive evaluation indicated that Residue mulching had the best comprehensive profit, traditional tillage had the worst. benefits of those tillage measurements were according to this sequence: residue mulching>no tillage>film mulching=winter wheat>traditional tillage.Generally speaking, conservational tillage (residue mulching, no tillage, and film mulching) can effectively store soil water, control wind erosion, heighten crop yield, and increase economy income, compared to traditional tillage. It's an effective way to control wind erosion, improve ecological environment in the process of agriculture production in sandy area. Though winter wheat generated relatively lower economy income, it increased surface cover of farmland in winter and spring, controlled wind erosion effectively, could be a fairly good measurement for farmland wind erosion control. It is suggested that government prompt winter wheat planting.