The Study On Remediational Effect Of Several Fertilization Structures On Acidic Vegetable Soil From River Deposit

This study used the alluvial vegetable soil which developed on river sediment at the terrance of Liuyang River in eastern suburbs of Changsha city, Hunan Province, as the experimental soil,. A plot experiment was performed at the local climatic conditions, as well as with field sampling and laboratory analysis to study soil fertility characteristics and acidification characteristics in five vegetable field soils in the suburb of Changsha city, and examined the improvement effect of soil fertility characteristics and acidification characteristics and influence of crop growth, nutrient uptake and yield by using different fertilization treatment in acid vegetable soils. All these were finally aimed at providing the scientific basis and technical support for the remediation of acidic vegetable soil, and raisinng fertilizer use efficiency. The results were as below:(1) Field investigation sampling and laboratory analysis results showed that soil fertility level in this5experimental fields is at medium and high level, organic matter、nitrogen and phosphorus are all rich in the experimental soils, especially Soil available phosphorus content was much higher than the cultivated soil, But appeared rich phosphate and potassium deficieny phenomenon in different degree. The content of CEC was low in this five experimental fields, which ranged from7to13cmol·kg-1with an average of10.2cmolkg-1.Soil fertility and acid acidic buffering ability was weak, and soils of the5experimental fields is being acidified, especially it is a strong acid soil in Donghu village, which soil already had some active Al3+be stripping, need to take the necessary measures.(2)The field plot experiment results showed that during the test, soil available nutrient contents in the alluvial vegetable garden soil were during the dynamic change. Under the same conditions of the nutrient application rate, the capacity of supplying soil available nutrient in different fertilization treatment was not same, the best treatment for supplying available nitrogen, available phosphorus, available potassium was NPK+VSF treatment, next was NPK+SR1treatment. To applying MgO and CaO could both adjust the soil pH, and the same unit of MgO was better than CaO. Although the effects of soil pH adjustment were not obvious by using acidification amendment SRI and acidification amendment SR2, but they could increase the contents of soil available nitrogen and soil available phosphorus, and promote crop absorption and utilization efficiency of nitrogen, phosphorus and potassium.(3)The field plot experiment results also showed that the use of chemical fertilizers could significantly reduce soil pH, bottom soil pH was higher than top soil pH about1.03units. MgO and CaO treatments could effectively reduce the surface soil sour degree, but the effect on the improvement of the bottom soil acidity was not obvious. Exchangeable acidity size and pH value had a inverse relationship, and only at the lower acidity, exchangeable aluminum ions could be appeared in soil. Top soil CEC values were relatively stable, soil CEC ranged from8to10.75cmol/kg with an average of9.05cmol/kg. Fertilizer and soil acidic buffering ability was weak in the tested soils.