Scientific Selection of Organic Fertilizers
Clarify the Core Classifications and Characteristics of Organic Fertilizers
Organic fertilizers are essentially organic-rich fertilizers formed by the decomposition and of animal and plant residues. They can be divided into four categories based on raw material sources.
Plant-derived organic fertilizers use raw materials such as straw, sawdust, and traditional Chinese medicine residues. They have a loose texture and high organic matter content, which can effectively improve soil permeability. However, their content of nutrients such as nitrogen, phosphorus, and potassium is relatively low, making them suitable as basic fertilizers for soil improvement.
Animal-derived organic fertilizers include livestock and poultry manure, bone meal, fish protein, etc. They have high and balanced nutrient concentrations, especially high nitrogen content, which significantly promotes the growth of leafy vegetables. However, attention must be paid to thorough to avoid the spread of diseases and pests.
Microbial organic fertilizers are made by adding functional microbial communities to traditional organic fertilizers. In addition to providing nutrients, they can inhibit pathogenic bacteria and activate soil nutrients through microbial activities, making them particularly suitable for improving the soil micro-ecological environment in continuous cropping plots.
Mixed organic fertilizers combine the advantages of various raw materials and achieve nutrient complementation through scientific proportioning, with a wider range of applications. However, attention should be paid to the compatibility of different raw materials to avoid nutrient antagonism.
Grasp the Core Criteria for Judging High-Quality Organic Fertilizers
When choosing organic fertilizers, first, pay attention to the purity of raw materials. The raw materials of high-quality organic fertilizers should be clearly traceable, avoiding the use of industrial waste or domestic garbage containing heavy metals, antibiotics, and hormones. For example, when using livestock and poultry manure from large-scale breeding as raw materials, it is necessary to confirm whether feed additives are used standardizedly in the breeding process; when using plant straw as raw materials, avoid using waste materials treated with chemical agents.
Degree of is a key indicator for judging the quality of organic fertilizers. Un organic fertilizers contain a large number of pathogenic bacteria and eggs. After being applied to the soil, they will produce high temperatures due to secondary fermentation, leading to root and seedling burning of crops. High-quality organic fertilizers are usually dark brown or black, with a loose texture and no agglomeration, and have a faint earthy smell rather than a pungent odor. A simple experiment can be used for auxiliary judgment: take a small amount of organic fertilizer, add water and stir, and after standing, the upper liquid is clear and not turbid, and the bottom sediment is fine and uniform, indicating sufficient.
In addition, nutrient content and proportion need to be matched according to planting needs. National standards stipulate that the organic matter content of organic fertilizers shall not be less than 30%, and the total nutrients (nitrogen + phosphorus + potassium) shall not be less than 5%. However, different crops have great differences in nutrient requirements. Leafy vegetables have high nitrogen requirements, so organic fertilizers with a prominent proportion of nitrogen can be selected; fruit trees need to increase the proportion of phosphorus and potassium during the fruit expansion period, so products with corresponding proportions should be preferred. At the same time, pay attention to checking whether the product has been tested by authoritative institutions, and the test report should clearly mark the specific values of various indicators.
Avoid Common Misconceptions in Selection
Many growers have the wrong perception that "the stronger the odor, the stronger the fertility". In fact, fully organic fertilizers have a mild odor, and a pungent odor indicates that they contain undecomposed harmful substances, which can easily cause soil acidification after use. Another misconception is blindly pursuing high nutrient content and ignoring the core role of organic matter. The primary function of organic fertilizers is to improve the soil. Overemphasizing the content of nitrogen, phosphorus, and potassium may lead to the addition of chemical fertilizers in the products, violating the original intention of organic planting.
At the same time, be alert to the publicity trap of "quick-acting organic fertilizers". The nutrient release of organic fertilizers depends on microbial decomposition and belongs to slow-release fertilizers. If it is claimed to "take effect quickly", it is likely that quick-acting chemical nitrogen fertilizers have been added, which will damage the soil structure after long-term use. When choosing, priority should be given to products with mature production technology and good reputation, rather than being misled by fancy marketing terms.
The correct selection of organic fertilizers is the basis for realizing green planting, which requires comprehensive judgment combining raw material characteristics, degree of，nutrient proportion, and other aspects. Scientific selection according to crop needs can not only improve yield and quality but also protect soil health, laying a solid foundation for the development of sustainable agriculture.