Hidden dangers in improper application of organic fertilizer

It is generally believed that organic fertilizer is safe. In the practice of organic agriculture, some developed countries advocate the application of organic fertilizer but reject chemical fertilizer. In the fertilizer standard of domestic green food, it is also stipulated that only organic fertilizer and microbial fertilizer are allowed. The so-called organic fertilizer refers to a variety of fertilizers that farmers use local materials and accumulate on their own, also known as "farm manure". Organic fertilizer is made from animals and plants rich in organic matter, which contains not only nitrogen, phosphorus and potassium necessary for plants, but also other nutrients, so it is also called complete fertilizer. Commonly used animal fertilizers such as human manure, stable manure, poultry manure, hoof horns of livestock, fish, bone meal, and plant fertilizers such as oil meal, green manure, bean cake, sauce dregs, rice bran, compost, pond mud, peat and so on. Organic manure must be fully ripened before it can be applied, otherwise it will be harmful to crops. It is generally believed that the application of a large amount of organic fertilizer can improve the soil, make the sandy soil fertile and the clay loose and easy to plough. in addition, it can coordinate the ratio of air to water in the soil, which is beneficial to the growth of crop roots and the absorption of water and nutrients. However, like chemical fertilizers, improper application of organic fertilizers will also bring ecological threats such as nitrate leaching and greenhouse gas emissions. At present, some developed countries have adopted legislation to control and guide the application of organic fertilizer in farmland. In recent years, with the rapid development of large-scale aquaculture in China, the contents of heavy metals and antibiotics in livestock and poultry manure have increased, and there are hidden dangers in the safety of organic fertilizer. So, how to apply organic fertilizer scientifically and reasonably? First, pay attention to the selection of high-quality organic fertilizer, and it is best to choose the one produced by regular factories when selecting commercial organic fertilizer; second, organic fertilizer must be fully ripened and applied; third, it is necessary to cooperate with the application of biological fertilizer, whether it is basic application or flushing application, it is best to combine with biological fertilizer, because after the combined application of organic fertilizer and biological fertilizer, the biological bacteria in biological fertilizer can accelerate the decomposition of organic matter in organic fertilizer, making it more conducive to crop absorption. Fourth, the application amount of organic fertilizer should be strictly controlled and should not be overused.