The Research On The Soil Quality In Sunlight Greenhouse

In the middle of shaanxi province, more and more peasants begin to adopt the sunlight greenhouse planting method. Although this method brings great profit to the peasant, it has inevitable negative influence to the environment at the same time. For example, these factors include the salt accumulation in the top soil, the soil diseases and insect pests, the soil degradation. The factors make the peasant have to give up the planting or take the top soil out the greenhouse because of the very low yield after 7 to 8 years. This thesis is based on the analyses of the soil physical and chemical properties, the soil microorganism and the enzyme of top-soil in different years of sunlight greenhouse in 10/1994 and 3/2005. Except that, we have a long time monitor method to observe the change of the nitrate content and the salt content in the soil profile from 0-180cm every two month between 5/2005 and 3/2006. I collected the sample in yangling city Shaanxi province. I get the conclusions as followed.1. In the sunlight greenhouse from one to six years, it had been found that the nutrient accumulation in soil profiles under sunlight greenhouse is almost larger than the content in opened fields.In the top soil, the content of O.M. and total N was much higher than the opened field. There had great accumulation of Avail. P and Avail. K (Aver. P: 113.61 mg/kg, Aver. K: 392.88 mg/kg). The content of total K and Alk. N had the increase trend in the longer years of sunlight greenhouse.2. The relationship of the number of the soil microorganism was that the number of the bacteria was larger than the number of the actinomycetes that was larger than the number of the fungi in sunlight greenhouse. There had a great relationship between the soil physical and chemical properties, the soil microorganism and the enzyme of top-soil. Be compared to the healthy plant, the number of the bacteria and actinomycetes declined greatly with the plant disease worsen in the out-root soil. On the other side, the number of the fungi had a rapid rise. We could witness the biggest number of the bacteria and actinomycetes in the in-root soil when the plant disease was in the middle stage. The change of the number of the fungi was same to the change in the out-root soil.3. The content of alkaline phosphates and urease and catalase were larger than that of the opened fields. The content of alkaline phosphates increased with the increase of the cultivation years. The content of urease peaked in 3 years sunlight greenhouse. The content of...