| A study on the economic and ecological environment effect of some ecological cropping patterns was made in typical purple soil of Three Gorges Reservoir area in this thesis. Five models such as pear ×Forsythia suspensa/peanut, pear/peanut, nectarine ×Forsythia suspense / peanut, nectarine/ peanut and rape/ peanut were set up in the catchment area of Honghua Reservoir in Shiwan small watershed of Kaixian county, the observed and counted items include: Investment cost, economic income, pear and nectarine crown size, soil bulk density , porosity of soil , fibrous roots size and soil nutrients.Research result shows:(1) Investment cost in the unit area , the pear ×Forsythia suspensa / peanut > the nectarine ×Forsythia suspensa / peanut> the pear/ peanut> the nectarine / peanut> the rape/ peanut; And the economic income in the pear ×Forsythia suspensa / peanut model is the highest, amounting to 67,200 yuan/hm2.a; The ratio of input to output of the economic benefit indices: the pear ×Forsythia suspensa / peanut > the nectarine ×Forsythia suspensa / peanut> the nectarine / peanut > the pear / peanut> the rape/ peanut, among them the economic income in two models for growing Forsythia suspensa are better, the value are 1.92 and 1.87, increase 69.9% and 65.5% respectively compared with the control model, but the economic income in traditional rape/ peanut is the worst.(2) The crown size affects the yield of fruit trees obviously. To pear crown size, its main influence factor is not the cropping patterns, not the position of slope, but the thickness of soil, the correlation coefficient r of pear crown size and thickness of soil is 0.7627; To nectarine crown size, the position of slope, cropping patterns and thickness of soil all affect it obviously, theABSTRACTcorrelation coefficient r of nectarine crown size and thickness of soil is 0.89.(3) Fibrous root is important organ and channel in obtaining water and nutrient from the soil, and is also an important factor to hold the soil and alleviate soil erosion. Fibrous roots size of the two models with intercropping Forsythia suspensa are much more than the other models by adopting analysis of variance, which proves Forsythia suspensa have lots of fibrous roots; Carrying through T-test on the pear ×Forsythia suspensa / peanut model and the nectarine ×Forsythia suspensa / peanut model, when a =0.05. signal diversity doesn't exist. It is mainly affected by planting density and distributing characteristics of trees roots. The factors affecting fibrous roots size besides the planting vegetation, it has signal positive correlation to thickness of soil, thick soil is good to the growth and development of plant roots.(4) Soil bulk density and porosity of soil have some effect on controlling on the water, fertilizer, heat, air of the soil, the quantity and quality of the porosity of soil may affect the percolation, water-holding, storage fertilizer and some other function of the soil. Cropping patterns and position of slope have obvious affection to the development of the porosity of soil, while their interaction has not obvious affection. The average porosity of soil to all the cropping patterns, the pear ×Forsythia suspensa / peanut > the nectarine ×Forsythia suspensa / peanut > the nectarine / peanut > the pear / peanut > the rape / peanut; The average porosity of soil to position of slope, the lower and middle of hill > the middle of hill > the lower of hill > the top and middle of hill > the upper of hill. The reason that porosity of soil of lower of hill is smaller than the lower and middle part's and the middle part's is the trample of man. The correlation coefficient r of porosity of soil and thickness of soil is 0.4558, they have linear correlation .(5)All the ecological cropping patterns have some improvement on a variety of soil fertilizer than the traditional cropping pattern, especially there are great improvement on the soil organic matter, available nitrogen and available phosphorus.(6)Combined with ecological and economic indices, th...
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