Effects Of Three Amendments On Cd Accumulation And Nutrient Uptake Of Vegetable

At present, amendment for phytoremediation of heavy metals in soil was limited to field of land for growing crops,that is committed to research on different kinds of vegetables have also been reported, However,that chooses the best amendment of the studies from different types of vegetables in different parts of the starting is reported rare. In view of this, this experiment uses artificial soil which is polluted by cadmium for test, choose lime,swine manure and SSP as soil amendment, through the root bag potted trial to research the effects of three amendments about Cadmium accumulation and nutrient absorption of three different types of vegetables of the Radish(Raphanus sativus), Lettuce(Lactuca sativa var.angustana) and Cowpea(Vigna unguiculata),and provides a theoretical basis for vegetable safety production and reference value. The main research results are showed as follows:1. Before planting vegetables and vegetable maturity, After exerting the amendment, the activity of soil enzymes(soil catalase,soil urease,soil sucrase and soil amylase)are improved.Among them,radish,lettuce and cowpea mature period catalase activity of rhizosphere soil achieves maximumin by pig manure(high concentration) treatment,that has been higher than the corresponding comparison was 127.52%,158.26% and 88.28% respectively. This show that the pig manure has a good action to improve soil ecological environment of vegetable under the cadmium pollution.2.Under different amendment processing the content of effective soil cadmium is obviously smaller than the comparison, the reduce rate is pig manure processing >superphosphate processing> the lime treatment, and along with its accession the concentration to increase content of the effective cadmium to reduce. Among them, radish, lettuce and cowpea mature period rhizosphere soil effective cadmium content achieves maximumin by pig manure (high concentration)treatment, that is lower than the corresponding comparison was 56.60%,50.00% and 57.14% respectively. Indicates the pig manure (high concentration) improvement effect obviously compared to other two kind of good. 3. After exerting the amendment, before the vegetables planter, and the vegetables mature period soil nutrient content is improved than the corresponding comparison, as a whole displays for the rhizosphere soil> the non-rhizosphere soil. And soil entire nitrogen, entire potassium and alkaline hydrolysis nitrogen, fast-acting potassium content achieves maximumin by pig manure(high concentration)treatment.However,entire phosphorus and fast-acting phosphorus achieves maximumin by SSP(high concentration) teatment.4. Three kinds of amendments obviously have suppressed the vegetables to the soil in the cadmium absorption. The radish, the lettuce and the cowpea its main edible partial cadmium content respectively in pig manure(high concentration)processing, lime (high concentration) processing and pig manure (low concentration)processing shows the minimum value, that is lower than the corresponding comparison is 366.90%,199.63%and 350.00%, and three vegetable content of cadmium in edible parts of its size displays for stem of lettuce> root of radish> pods of cowpea. Therefore,the cadmium pollution of a more serious in soil, priority to planting Cowpea.5. At vegetable maturity,Three vegetable edible parts total nitrogen, total phosphorus content in SSP (high concentrations) process reaches the maximum value, its value was 1.22%,1.35%,2.95% and 1.26%,0.92%,1.09% respectively, but the total potassium content in pig manure (high concentrations) process reaches the maximum value, its value was 28.55%,24.75%,23.38% respectively.The main edible partial of the Radish, Lettuce and Cowpea increase over the corresponding comparison 92.48%,154.30% and 189.55% respectively.