The use of nitrogenous fertilizer in vegetable gardens is one of the effective measures to increase the yield of vegetables, but if used improperly, it will cause pollution to vegetables and reduce the quality of vegetables. To reduce the pollution of nitrogen fertilizers on vegetables, we must pay attention to the following four points: Deeply cover soil. Deep application of nitrogen fertilizer can reduce its direct contact with air and sunlight, so as to avoid volatile loss and pollution of vegetables. Generally, nitrogen fertilizer should be applied in a depth of 10-15 cm. For planting roots with developed root vegetables, dioscorea and root vegetables, nitrogen fertilizer should be applied deep to the root layer below 15 cm. Apply early. For leafy vegetables and vegetables with short growing period, nitrogen fertilizer should be applied as soon as possible. Generally, it is better to apply it at the seedling stage, and nitrogen fertilizer should not be used excessively during the late growth period of vegetables. For vegetables that do not absorb nitrate easily, nitrogen fertilizer should be stopped 30 days before harvest. Control usage. Nitrate accumulation in vegetables will increase with the increase in the amount of nitrogen fertilizer application. Therefore, the amount of nitrogen fertilizer applied and the number of applications should be minimized. Generally, the amount of nitrogen fertilizer per acre should be controlled below 20 kg nitrogen, and the vegetable fields with higher fertility should be controlled under 10 kg or no nitrogen fertilizer. If nitrogen fertilizer is required, 70-80% of nitrogen fertilizer should be used as a base fertilizer, and the rest should be used for deep seedling application. Avoid spraying on foliage. Leafy vegetables should not be sprayed with nitrogen fertilizer. Because ammonium ions in nitrogen fertilizers are easily converted into nitrate ions when they come in contact with air, they are absorbed by leaves, and the short growing period of leafy vegetables makes it easy for nitrates to accumulate in leaves. Therefore, do not apply foliar nitrogenous fertilizers to leafy vegetables. In particular, foliar sprays must not be conducted within 28 days before harvest to prevent contamination of vegetables. Fungi, a large class of chlorophyll - free, can not carry out photosynthesis, heterotrophic lower class of plants. These include bacteria, slime molds and fungi. Their common characteristics are: the plant body has no differentiation of roots, stems and leaves, does not contain chlorophyll and other photosynthetic pigments (except a few photosynthetic bacteria), can not carry out photosynthesis, saprophytic life or parasitic life, that is, heterotrophic life. Most of the reproductive organs are single-cell structures, and the zygotes do not develop into embryos. Ganoderma Lucidum Extract,Lion's Mane mushroom Extract,Chaga Mushroom Extract Xi'an Double H Health Technology Co., Ltd , https://www.xadoubleh.com