蔬菜大棚土壤养分变化和盐分累积特征研究

目的]为解决棚龄长的耕层内盐分含量高,微生物组成发生明显变化,直接导致蔬菜病虫害加重、产量下降、品质变劣的问题。方法]研究了江苏省淮安市的不同使用年限的塑料大棚的土壤养分变化和盐分累积情况。结果]所有大棚内碱解N都超过了140mg/kg;4年龄棚比1年龄棚、3年龄棚比2年龄棚速效P含量分别增加48.561、3.52 mg/kg;棚龄3年、4年的大棚有效K分别为96.88、138.4 mg/kg;棚龄4年的土壤pH值为5.12;4年大棚的表层土水溶性盐含量达到了4.62 g/kg。结论]大棚内土壤有效养分含量均高于露地,0~20 cm土层的含量随种植年限的增加而增加;棚龄4年的大棚土壤pH值已呈一定的酸化;大棚土壤的水溶性盐分明显高于相邻露地,多数已达中度盐害程度。

Study on Soil Nutrient Variation and Salt Accumulation Characters in Vegetable Greenhouse

Objective] The purpose was to solve the problems such as vegetable pests and diseases aggravating,yield decreasing and quality becoming inferior directly caused by high salt content in cultivated layer in the greenhouse with long term and obvious change of microbe composition.Method] The soil nutrient variation and salt accumulation situation in greenhouse with different cultivation years in Huaian city of Jiangsu province were studied.Result] The alkaline hydrolytic nitrogen amount in all the greenhouses was over 140 mg/kg.Compared with 1-year-old greenhouse,the quick-acting phosphorous content in 4-year-old greenhouse increased 48.56 mg/kg.Compared with 2-year-old greenhouse,the quick-acting phosphorous content in 3-year-old greenhouse increased 13.52 mg/kg.The available potassium(K) amounts in 3-year-old and 4-year-old greenhouses were 96.88 mg/kg and 138.4 mg/kg respectively.The pH value of soil was 5.12 and the water soluble salt content in top soil achieved 4.62 g/kg in 4-year-old greenhouse.Conclusion] The available nutrient content of soil in greenhouse was higher than that of open field and increased in 0～20 cm soil layer along with the cultivation years increasing.The pH value of soil was acidified to some extent in 4-year-old greenhouse and the water soluble salt content was obviously higher in the greenhouse than that of neighbor open field,and the majority had achieved the mid-degree of salt harm.