Advantages and disadvantages of slow release fertilizer

This year's Central Committee document No. 1 mentioned "launching a pilot project to subsidize the use of high-efficiency slow-release fertilizers", which provides a great opportunity for the development of slow-release fertilizers. Because of this, slow-release fertilizer has become a hot topic in the industry. The most important characteristic of slow-release fertilizer is that it can control the rate of nutrient release, decompose gradually after being applied to the soil, and gradually absorb and utilize it for crops, so that the nutrients in the fertilizer can meet the different needs of different growth stages of crops. After one application, the fertilizer effect can be maintained for several months or even a year. The experimental study shows that the fertilizer efficiency of slow release fertilizer is at least 20% higher than that of similar conventional fertilizers, which can reduce the loss of fertilizer nutrients, especially nitrogen in the soil, reduce environmental pollution, and help to protect the ecological environment; reduce the number of fertilization operations, save labor and costs, and avoid damage to seeds or seedlings caused by excessive fertilization It is beneficial to improve the quality and food safety of agricultural products (8.77 and 0.11%). But everything is divided into two, slow-release fertilizer itself also has a lot of shortcomings. Nutrient release is difficult to be consistent with the law of crop fertilizer absorption. The amount of nutrients absorbed by any crop, especially grain, vegetables and fruits, is different in different growth and development periods, and the fertilizer requirements of different crops are also different. However, as far as the current production technology and technology of slow-release fertilizer are concerned, especially restricted by coating materials, it is difficult to produce slow-release fertilizer whose nutrient release rate is consistent with the fertilizer requirement of crops, especially grain, vegetables and fruits at home and abroad. it is basically the same amount of release, and there are still problems of large release in the middle and early stage and small release in the middle and later stage. This is also one of the main reasons why slow-release fertilizers are difficult to be popularized in a large area in the production of major crops. The evaluation of fertilizer effect is relatively simple. At present, the evaluation of the fertilizer efficiency of slow-release fertilizer is basically based on the conventional field contrast experiment and production investigation, and the effect is still evaluated by routine, that is, the comparison between input and output. Ecological benefit should be one of the most important benefits of slow-release fertilizer, which is also the most important factor in the development of slow-release fertilizer. However, the current field experimental conditions and methods are difficult or impossible to detect the nutrient release rate and fate of slow-release fertilizers. In addition, there are many effects on the nutrient release rate of slow-release fertilizer under natural environmental conditions, which makes it more difficult to detect the nutrient release rate and destination of slow-release fertilizer. It is also the fundamental reason for the lack of quantitative evaluation of economic and environmental benefits of slow-release fertilizers. Therefore, it is necessary to further systematically and strictly evaluate the fertilizer efficiency of slow-release fertilizer application in the field and its morphological transformation and destination in soil, so as to make the nutrient release rate of slow-release fertilizer more close to the law of crop fertilizer absorption. to maximize nutrient utilization and minimize nutrient loss. Lack of uniform standards. At present, there is not a unified standard for the test methods of fertilizer controlled release performance in the world or in the industry, so it is imperative to establish a standard test method for fertilizer slow release performance to promote and ensure its industrial quality. At the same time, fertilizer production technology and technology and on-line quality inspection technology need to be further improved to meet the needs of the development of slow-release fertilizer industrialization. The cost is too high. Farmers are the users of slow-release fertilizer, which is one of the key factors for the development of slow-release fertilizer industry. Compared with conventional fertilizer, the production cost of slow release fertilizer is 1 to 4 times higher, so that most of this kind of fertilizer is only used in the production of flowers and lawns with high economic value, which limits its wide use. Although the Central Committee document No. 1 clearly mentioned subsidies for the use of slow-release fertilizers, the most important thing is whether the national financial resources can bear the burden of large-scale use of subsidies, and the second is whether the state can continue to subsidize for a long time. Therefore, without solving the problem of high price of slow-release fertilizer, it is difficult to ensure the sustainable development of slow-release fertilizer industry only by national financial subsidy. These problems not only need the government to formulate relevant supporting policies such as taxation and subsidies in the development and promotion of slow-release fertilizers, but also need scientific research departments and production enterprises to solve the shortcomings and problems of slow-release fertilizers in view of the current shortcomings and problems, in order to achieve the sustainable development of slow-release fertilizer industry.