Contents of nitrate and mineral elements and their relationships in leafy-vegetables

The contents of nitrate，mineral nutrient elements and their rdationships are studied in twenty-three leafy-vege-tables in Chongqing．The results show that the content variations of nitrate and mineral elements are very great in the different vegetables and the different varieties；other vegetables especially celery are polluted by nitrate except asparagus lettuee ，west-romaine lettuce，pack-choi．The significant or very significant positive corrdation in N，P and K and other mineral nutrient dements．In fresh leafy-vegetables，the correlation is significantly or very significantly positive in NO^-₃and K，Na，Ca and Fe，and is negative in NO^-₃and P，S，Mn，Zn，B and Mo in the dry vegetables，moreover there is a significantly negative relationship between NO^-₃ and B and P．