The observation point of fertilizer efficiency of organic fertilizer can improve the three major properties of soil: physics, chemistry, biology, far better than fertilizer supply capacity

Taiwan is located in the subtropical zone. Due to the high temperature and humidity and intensive farming, soil organic matter is easily decomposed. In order to maintain soil productivity and fertilizer efficiency, proper content of soil organic matter is the key, and the application of organic fertilizers is the most effective way. Furthermore, the rising awareness of environmental protection in Taiwan in recent years and the need to take into account the quality and safety of food have made the use of organic fertilizers re-emphasized.

Improve soil physical and chemical properties, organic matter promotes crop growth

The application of organic fertilizers has multiple effects on crop growth, including direct and indirect effects. There are many ways to apply organic fertilizers to improve soil physical properties, such as stabilizing soil aggregate structure by humus in compost; adjusting soil aeration, supplying enough oxygen to the root system, and removing excess carbon dioxide from the rhizosphere; the darker compost color can promote The soil absorbs heat energy, increases the soil temperature and indirectly improves the soil structure; the organic matter loosens the solid soil, reduces the overall density of the soil, avoids poor drainage, surface erosion and other effects, makes the root system of crops develop and stretch, and enhances the root system to absorb water and nutrients, etc. Crop quality is also improved. In addition, the high content of soil organic matter and the abundance of earthworms in the soil result in more vermicompost, and the soil aggregate structure is good.

Soil chemistry also improved following the application of organic fertilizers. Soil can preserve more nutrients needed by plants for a long time, and increase soil cation exchange capacity (CEC), anion exchange capacity (AEC) and buffer capacity; this is more important in soils with low clay and organic matter content. Furthermore, it can also increase the soil's ability to store nutrients. The organic fertilizer contains all the nutrients needed by plants, which can increase the soil nutrient content.

Organic fertilizers have a large buffer capacity, so that the soil will not change greatly in pH and conductivity due to foreign chemical fertilizers. The test results of the agricultural improvement field in Tainan District of the Agricultural Committee show that the high content of organic matter in the melon field can slow down the damage of excessive electrical conductivity.

In addition, it can clamp micronutrients. In a broad sense, organic matter includes organisms, organic residues, and humic substances. In a narrow sense, organic matter refers to humic substances. Soil organic matter can be divided into organic residues and humic substances. Because humic substances have several oxygen-containing functions It has various colloidal properties, such as surface adsorption, ion exchange, clamping (chelation, clamping), buffering, redox, physiological activity, etc.; and can assist in the dissolution of plant nutrients, help absorb and improve effective sex.

Organic matter is not only an energy source for soil microbial activity, but also a source of organic and inorganic nutrients. Soil organic matter content is high, and there are many types and quantities of microorganisms, which can promote the decomposition of organic matter and release the inorganic nutrients needed by plants. Organic fertilizers may also promote the growth of certain auxin-secreting microorganisms. As Lin Yonghong, associate researcher at Kaohsiung District Agricultural Improvement Field, Agricultural Committee of the Executive Yuan, pointed out in his research on the effect of humic acid on crop growth, the humic acid in soil humus has similar plants. Auxin properties that promote plant growth.

Master the three elements of organic fertilizer quality: large supply, fast release, and high degree of decomposing

Organic fertilizers are a way to reuse resources. If organic wastes are not used or digested by the soil, they will be discharged into the environment, resulting in waste of resources and pollution of the atmosphere, water surface and soil. Today, the main purpose of composting is not just to provide nutrients, but to make waste harmless, so organic waste can be turned over moderately.

The quality of organic fertilizers will affect the impact on soil, crops and the surrounding environment after application, which in turn affects farmers' willingness to purchase and use them. The basic requirements of high-quality organic fertilizers include multiple functions such as supplying the nutrients needed by plants, improving soil structure, adjusting soil moisture, aeration and temperature, and activating soil phosphate fertilizer; the dual effect of improving crop yield and quality; being friendly to the surrounding environment and not producing peculiar smells ; Buffer ability to external environmental impact; less adverse side effects.

Left picture: Cantaloupe field A test area with low soil organic matter, low buffering property and high electrical conductivity, plants wither; Right picture: Cantaloupe field B test area with high soil organic matter, high buffering property, high electrical conductivity, plants Fertility is better.

Replacing chemical fertilizers with organic fertilizers to supply crops needed for growth is often used in organic farming. Because the content of nitrogen, phosphorus and potassium in organic fertilizers is very different from that of chemical fertilizers, for example, the nitrogen content of urea is as high as 46%, while the general organic fertilizer is only 1% to 6%, and its organic state must be mineralized into inorganic substances by microorganisms. It has the same effect as chemical fertilizer. If chemical fertilizer is completely replaced by organic fertilizer, a large amount of organic fertilizer and conditions suitable for mineralization are needed to cooperate. Therefore, to fully meet the nutrient requirements of crops, the estimated amount of organic fertilizers will be very large. At the same time, if applied in large quantities, it may cause irremediable sequelae, such as excessive accumulation of salt or heavy metals, thereby destroying soil quality and reducing soil productivity.

Therefore, compost with the purpose of supplying nutrients should meet three conditions, namely, large nutrient supply, fast nutrient release rate and high decomposing degree. Use organic fertilizers with high content of 3 elements, low carbon-nitrogen ratio (<17) and high fertilizer content. Because mineralization is greater than biological immobilization, nutrients can be quickly released for crop absorption, such as meal fertilizer, poultry Animal manure and its compost, animal material fertilizer, etc., have such conditions.

The main types of oil meal fertilizers include more than 20 kinds of soybean meal, peanut meal and rapeseed meal. They still contain oil, and the main components are protein and carbohydrates. Because it is rich in nitrogen and lacks phosphorus and potassium, it should be mixed with superphosphate and plant ash (palm ash). Plant ash not only supplies potassium, but also promotes the decomposition of oil and neutralizes the organic acids produced during decomposition. Any combination of fertilizers will not affect the quality.

However, the decomposition in the soil requires the participation of microorganisms, so the decomposition is slow in the cold season, and it should be used as a base fertilizer; In recent years, commercial fertilizers have been developed towards the types of organic compound fertilizers (adding peat) and biotechnology fertilizers (combining with beneficial microorganisms and organic materials as three elements). Causes soil conductivity is too high, affecting crop growth.

Fresh or immature organic fertilizers, once applied to the soil, may have many negative effects. The heat and toxic volatile gases generated by continued fermentation, such as methane and hydrogen sulfide, will damage plant roots, inhibit growth, and bring pathogens. etc., the use of organic fertilizers of unknown origin should be avoided.

High efficacy and high stability, effectively improving soil quality

Organic fertilizers are rich in organic matter. In addition to supplying nutrients, the effect of improving soil properties is unmatched by chemical fertilizers. In general, the application of organic fertilizers has a greater contribution to the improvement of soil physical, chemical and biological properties than the supply of nutrients. The most correct and appropriate fertilizer management strategy should be the use of organic fertilizers to improve soil properties and long-term release of nutrients required by crops, combined with the quick-acting characteristics of chemical fertilizers, to create a harmonious, reasonable, environmentally friendly and sustainable agricultural production pattern.

The application of organic fertilizers of poor quality may easily produce miscellaneous bacteria due to incomplete fermentation.

In order to improve soil properties, the quality of organic fertilizers should have long-term utility characteristics. Not all organic fertilizers can effectively improve soil organic matter. Only those with high content of cellulose, hemicellulose and lignin have an effect. Usually, the content of fertilizers is low and crude fiber is low. Materials with high content, such as bark, cow dung, space bag, bagasse, straw, rice husk, etc. compost; and chicken manure, rice bran, fish fertilizer, soybean meal and other high-nitrogen components, the effect of increasing soil organic matter content is limited. Furthermore, it must have high stability. The characteristics of high stability are closely related to the structure and shape of organic materials. The more stable the two are, the less likely they are to be decomposed. Generally, long-term organic materials have high stability.

In line with the crop growth cycle, rational fertilization has its own essentials

Rational fertilization is a fertilizer management method that is suitable for the right place, time, and crop, and must fully meet the needs of crops and soil. There are many types of organic fertilizers, and the fertilizer efficiency varies according to the nutrient elements released by the organic matter contained in the soil through microbial decomposition and mineralization. Therefore, the application of organic fertilizers should be based on its carbon-nitrogen ratio to estimate the rate of mineralization and the release of nutrients. quantity of elements. When using organic fertilizers continuously, it is necessary to evaluate the mineralizable amount of organic matter in the soil in the early stage, so that the amount of elements that must be supplied by organic matter can be clearly understood. If chemical fertilizers and organic fertilizers are applied in combination, the amount of organic fertilizers that can be released should be deducted from the amount of chemical fertilizers applied to achieve the goal of rational fertilization.

When applying organic fertilizers in vegetable gardens, soil properties must be considered. In low-fertility, sticky or sandy loam soils, it should be collected once or twice if economic conditions permit. A large amount of high-fiber and refractory organic fertilizers should be applied, which can significantly improve the soil. Water retention, fertility retention, increase ventilation and buffering properties, etc., make it have good physical, chemical and biological properties, and then according to the adjusted properties, rationally mix and apply chemical fertilizers. Vegetable gardens with high fertility and high organic matter should use organic fertilizers containing high nitrogen and easily decomposed, such as oil meal, etc., which can not only reduce the application amount, avoid excessive accumulation of nutrients such as phosphorus and potassium, and quickly decompose to produce nitrogen , which can adequately supply the needs of vegetable growth.

Hole-applied organic fertilizer can be fully mixed with soil, and soil covering can reduce fertilizer loss and promote fertilizer efficiency.

Fruit trees are perennial crops. Because of the growth of branches and leaves and flowering and fruiting, they must absorb a large amount of nutrients from the soil each year, and their roots are deep. Therefore, the amount of fertilization, fertilization method, fertilization location and vegetables are different. Fertilizers must be applied to deeper soil layers to promote downward root growth, and can improve fertilization efficiency and promote fruit tree growth. The suitable type is high-fiber organic fertilizer, combined with the application of chemical fertilizer, to adjust the absorption pattern of the three elements to facilitate growth and improve quality.

Choose suitable organic fertilizers, and "soil" is the correct fertilization object

Due to the different materials and mixing ratios of organic fertilizers, the ingredients contained in them are also different. In order to balance the nutrient supply and prevent the excessive accumulation of heavy metals in the soil, especially the compost of livestock manure, organic fertilizers made of different materials should be applied in turn. Also equivalent to rotation. In addition, many organic fertilizers in Taiwan have a high pH value, which can be selected according to soil properties.

Organic fertilizers can not only help the soil fully supply the nutrients, water and oxygen needed by crops, but also ensure good soil physical, chemical and biological properties, reduce soil fertility deterioration, and reduce the application of chemical fertilizers and the occurrence of pests and diseases, making farmland easy to manage, Save trouble and worry, and maintain good productivity to meet human food needs. Fertilizer management is about fertilizing the soil, not the crops. Only healthy soil can produce healthy crops. Therefore, the content of organic matter in organic fertilizers has become the most important indicator. Enhance the function of organic fertilizers to improve soil properties, promote crop growth, and improve crop quality.