A treatment method for a heavy
metal contaminated farmland comprises the steps that the types and contents of
heavy metals in soil are detected; a DTPA extraction method is adopted to determine the contents of
heavy metals, capable of being absorbed by plants, in the soil are determined; the contents of
nutrient substances in the soil are detected, wherein the contents of the
nutrient substances comprise the content of
soil organic matter, the content of
total nitrogen, the content of available
phosphorus, the content of quickly acting
potassium, the
cation exchange capacity, the unit weight and the like; chemical leaching is conducted; the contents of the
heavy metals, capable of being absorbed by plants, in the soil are determined; the contents of the
nutrient substances in the soil are detected, if the contents of the nutrient substances in the soil are low, corresponding nutrient substances are supplemented into the soil, so that the contents of the nutrient substances in the soil reach the third
soil fertility grade or above; crops are planted in the leached soil, after the crops are harvested, the contents of the heavy metals in edible portions of the crops are detected, and when the contents of the heavy metals in the edible portions of the crops meet the national
food safety standard in the Maximum levels of Contaminants in Foods, it is judged that
soil treatment is completed. According to the treatment method for the heavy
metal contaminated farmland, bio-available components, harmful to the crops, of the heavy metals in the farmland can be effectively removed through chemical leaching, and
crop plantation can meet the requirement for safety production.