Pollution-free Vegetable Production Needs "Three Levels"
With the continuous improvement of people’s living standards and China's accession to the WTO, people’s demand for vegetables has become increasingly stringent, especially for the “safety†of vegetables. There is also a strong demand for vegetable production in accordance with the requirements of pollution-free vegetables. Row. Among the many links in the production of pollution-free vegetables, the most important ones are the following “three levelsâ€. One is the environment of origin. The production environment is the prerequisite for the production of pollution-free vegetables. The place of production should be chosen as having a good ecological environment. The production area and the upper reaches of irrigation are not directly or directly contaminated by industrial “three wastesâ€, urban domestic waste, and medical waste. The well is located 100 meters away from the main road of the highway. The background value of soil heavy metals is high, pathogenic microbial contamination is serious, and high-risk areas with endemic diseases related to soil and water sources cannot be used as pollution-free production areas. Establish the environment before the place of origin to include the soil (projects include ph, cadmium, lead, mercury, arsenic, chromium, hexachlorobiphenyl, DDT), water quality (projects include ph, cadmium, lead, mercury, fluorine, arsenic, hexa-phenol chrome, cyanide Chemicals, chlorides, atmospheric nitrogen (NOx, sulfur trioxide, fluoride, etc.) are monitored and monitored in accordance with the requirements of the "Hazardless Agricultural Products - Environmental Standards for Production Sites" to establish a base. Pesticides are another important factor causing human-induced pollution of vegetables and affecting the quality of vegetable products.Pollution-free vegetables should be strictly screened for the use of pesticides, preferential use of biological pesticides, and selective use of high-efficiency, low-toxicity, low-residue pesticides. At present, the commonly used insecticides produced include b/t series, avermectin series, insecticide esters, plant extracts, insect hormones (mimantan, casketoxin, and taitaibao), and a few organophosphorus pesticides. Fruits, trichlorfon, phoxim, thoms, farmland) and other pesticides such as dimehypo, imidacloprid, etc.; bactericides include carbendazim, thiophanate, glucosyl, prochlorant, bor, B grass It is forbidden to use high-toxic and high-residue pesticides such as methamidophos, carbofuran, insecticidal guanidine, omethoate, dicofol, methyl 1605, etc. At the same time, the length of time from the last application to harvest time, that is, pesticides, should be strictly controlled. The safety interval is 3-5 days for general biological pesticides, 5-7 days for pyrethroid pesticides, and 7-10 days for organic phosphorous pesticides (a few for more than 14 days), except for fungicides except chlorothalonil and carbendazim for 14 days. The rest is 7-10 days.The third is the application of fertilizers.The improper use of chemical fertilizers, especially nitrogen fertilizers, is another factor that leads to the enrichment of nitrates in the plants and the pollution of vegetables.Non-polluted vegetables should be fertilized to increase soil fertility and reduce Nitrate content, improvement of vegetable quality and increase of yield are the guiding ideologies.Fertilizer should be dominated by organic fertilizers, and formula fertilization should be promoted to control nitrogen, stabilize phosphorus, increase potassium, and promote application of microbial fertilizer, compound fertilizer, and vegetable-specific fertilizers. Targeted use of micronutrients, timely and appropriate application of nitrogen fertilizer, but the amount of application, 20 days before harvest, the use of chemical fertilizers is prohibited to reduce the pollution of vegetables.