| Orchard intercrop is a traditional grand utilization mode in three gorges reservoir area, which is effective in using resources and enhancing efficiency of resource use, and have good ecologic and economic values.But water and soil loss heavily in traditional pattern and can't keep up with need of modern orchard, especially to many new slop-grand young orchard.Based on the orchard actuality,a jumped-up orchard intercrop pattern was fetched in.In this paper, we adopted investgation on the spot (integating local statistical datum) and experimenting outdoors. Four patterns, including pear dry rice,pear sweet potato,pear peanut and bare pear orchard were analysed.The results were as follows:1.Three gorges project is a very good opportunity to develop of fruit industry in the whole three gorges reservoir. We should change fruit distribution step by step. Fruit tree species matching and breed arranging must be reasonable for many new orchard. Many biggish potential fruit ,such as pear, plum, which holding high yield, ratio of output and devotion, average production value and fluctuating, should be selected to become main fruit tree species. Based on these analysis ,we fetched in a new intercrop pattern of young pear orchard intercropping dry rice.2. We added up three times rainfall and average during the whole experiment. Pathway depth (modulus) ranked in order from smallness to bigness: pear dry rice ,pear sweet potato, pear peanut and bare pear orchard. Results indicated that over 32.6% rainfall will loss by pathway, if crop doesn't cover with the earth's surface of orchard. Some crops holding robust roots can reduce modulus and rainfall remarkably, example .growing dry rice in orchard.3 .Lossing amount of water and soil of four patterns during three times added up to 100.86mm are the followings respectively: Lossing amount of water and soil of pear dry rice is160.857t/hm2, that of pear sweet potato is 188.981 t/hm2, that of pear peanut is 217.48 t/hm2 and that of bare pear is 328.814 t/hm2. Lossing amount of pear dry rice is the lowest and bare pear is reverse.Total amount of soil corroding of bare pear is also the highest(2243.43kg/ hm2 ),but that of pear sweet potato is reverse. Pear peanut, pear dry rice and bare pear is 3.77 time ,2.20 time and 8.29 time than that of pear sweet potato respectively. We can draw a conclusion that soil corroding is very serious in slop-pland young orchard if there are not crop covering with the earth's surface of orchard. Besides, how to select intercrop crop is important ,because remarkable difference of soil corroding lied in different intercrop crop.4.Based on the amount of water and soil loss every 10mm rainfall and 100% of water and soil losing ratio of bare pear orchard, ratio of rainfall and soil preserving of other patterns are the followings; that of pear sweet potato is 13.65% and 87.93%,that of pear peanut is 10.33% and 54.48% and that of pear dry rice is 15.77% and 73.39%.Among 4 patterns, power of soil keeping ofpear sweet potato is the best,but that of rainfall keeping is common. Power of soil and rainfall keeping of pear peanut is relatively low. Power of rainfall keeping of pear dry rice is the best and that of keeping soil is good.5.The result of experiments with organic substance corrasion showed that content of organic substance is from 3.01% to 22.87%. Content of organic substance of corraded soil of Pear sweet potato is 13.38%,that of pear peanut is 13.41%,that of pear dry rice is 4.12% and that of bare pear orchard is 3.81%.The reason why content of organic substance of intercropping sweet potato and peanut is high is that fertilizer is used in seeding.Of course ,no matter which pattern.corraded soil with pathway hold plentiful organic substance.So little water and soil lossing have serious damage on soil.6. Compared with bare pear orchard ,other patterns can improve soil physical character.but the content of soil total N.available N.total P and available P fall.Only organic substance content increased in Pear dry rice. All these re... |
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