钾肥对铅污染土壤白菜生长及品质的效应

Effects of Potash Fertilizer on Cabbage Growth and Quality in Lead-Polluted Soil

为阐明钾对铅污染土壤白菜生长品质及食用安全性的影响,通过盆栽试验研究2种浓度铅污染土壤下不同钾肥施用量对白菜生长、生理特性、重金属含量及食用品质的影响。结果表明,铅污染土壤增施钾肥白菜地上部和地下部生物量分别显著提高5.1%~30.0%和10.0%~33.3%（P〈0.05）。铅污染土壤增施钾肥（100~400mg·kg-1）可显著提高白菜叶绿素a含量（P〈0.05）,叶绿素b含量变化不明显。铅污染土壤增施钾肥能显著降低白菜中镉、铅、铬和砷含量（P〈0.05）,显著提高维生素C含量（P〈0.05）,显著降低硝酸盐含量（P〈0.05）,但对白菜还原糖含量的影响不一致。该试验条件下铅污染土壤白菜最佳施钾浓度为200~400 mg·kg-1。

In order to further explain how potassium affects cabbage growing in lead contaminated soils in growth and quality, a pot experiment was carried out to study effects of dosages of potash fertilizer on yield, chlorophyll content, nutritionand mineral content of the cabbage growing in two soils different in lead contamination degree. Results show that after application of potash fertilizer the cabbage in the leadcontaminated soil increased by 5.1%-30.0% and 10.0%-33.3% infresh weight of the aboveground part and the underground part, respectively（P〈0 05）. Application of potash fertilizer ata rate of 100-400 mg·kg-1 could increase the concentration of chlorophylla significantly（P〈0 05）, while that of chlorophyllb did not show any constant changes. Potash fertilizer application was found to significantly decrease theconcentration of Cd, Pb, Cr and Se（P〈0 05）, increase the concentration of vitamin C（P〈0 05）, decrease the concentration of nitrate（P〈0 05）, but did not have any constant effects on reducing the concentration of sugar. The findings inthe study indicate that the optimal dosage of potash fertilizer is about 200-400 mg·kg-1 for cabbage in leadstress soils.