The issues of soil management and fertilization in agricultural production

Soil is the core of agricultural production, and its quality and fertilization management directly affect crop yield, ecological environment, and human health. In agricultural production, the problems of imbalanced soil management and improper fertilization are prominent, leading to the polarization of soil organic matter, nutrient imbalance, and compaction pollution, which restrict the high-quality development of agriculture. This article analyzes the relevant pain points, providing a path for constructing scientific soil management and fertilization models, and promoting green and sustainable agricultural development.
1、 Current soil management issues in agricultural production
Soil resources can only fully play their due role on the basis of rational development, utilization, and management. If we only focus on current interests in agricultural production and neglect the scientific utilization and management of soil, a series of agricultural production problems will arise. For example, the dependence of soil on fertilizers is becoming increasingly strong, and agricultural products are facing problems such as unappetizing grains, sweet fruits, and vegetables that cannot be cooked properly.
At present, soil management issues in agricultural production are quite serious and widespread, which have greatly affected the normal operation of agricultural production. These issues can be summarized as follows:
1. There are two extremes in the content of organic matter in soil: organic matter in soil refers to the general term for all organic matter in soil, including various organic compounds and organic biological residues. It comes from the return of various animal and plant residues in soil and the use of Organic Fertilizers by humans, and is one of the important components of soil. The amount of it directly affects the fertility of the soil, the physical and chemical properties of the soil, and the growth and development of plants. At present, in agricultural production, on the one hand, due to insufficient or no adequate supplementation of organic fertilizers, the organic matter content in most farmland soils has shown a decreasing trend year by year. The physical and chemical properties of the soil have deteriorated, and the basic fertility of the soil tends to decline, resulting in a decrease in the soil's resistance to adverse external environments; On the other hand, a small portion of protected soil, due to excessive supplementation of organic fertilizers, has caused the organic matter content in the soil to seriously exceed its suitable range, resulting in some negative impacts. The most obvious manifestation is the significant increase in the number of plant pathogenic bacteria in the soil, the aggravation of plant diseases and pests, and the increasing use of chemical pesticides year by year, leading to an increase in pesticide residues in crop fruits. If this situation continues, it will inevitably pose a great threat to human health.
2. Serious imbalance of plant nutrients in the soil: Due to year-round fertilization and unreasonable soil utilization, certain nutrients in the soil have become severely imbalanced, leading to widespread "anemia" and "accumulation syndrome" in farmland soil. This not only affects the yield of agricultural products but also causes a serious decline in the quality of agricultural products, resulting in an imbalance of nutrients in agricultural products, ultimately endangering human health. The so-called anemia refers to a significant lack of nutrients required for the growth and development of certain plants in the soil, while eutrophication refers to a significant increase in the content of certain plant nutrients in the soil, exceeding the appropriate level. For example, the accumulation of aluminum in the human body can cause damage to certain nervous systems, leading to the development of Alzheimer's disease; Due to the lack of selenium in food, the risk of cancer in humans may greatly increase.
3. The phenomenon of soil compaction and aging is becoming increasingly serious: due to the decrease and aging of organic matter content in the soil, unreasonable soil cultivation and management, and a single type of fertilization, the compaction and "more planting, more mixing" phenomenon of farmland soil is commonly occurring, resulting in an increase in soil productivity and fertilization management costs year by year.
4. The phenomenon of soil pollution has significantly worsened: due to the lack of attention to soil utilization and management, especially the blindness in fertilization and plant protection, the current farmland soil has experienced serious pollution. The significant accumulation of toxic and harmful substances in the soil has led to plant pollution, and the excessive content of certain toxic and harmful substances in agricultural products and fruits. What phenomenon does it indicate that lice, which were commonly found in rural areas, are now rarely seen? Perhaps it is not only determined by the improvement of rural hygiene environment, but also related to the unsafe food that humans often consume.
The emergence of the above problems largely depends on human fertilization management of soil and unreasonable and blind utilization of soil.

1. Pay attention to the quantitative application of organic fertilizers. Generally speaking, the organic matter in farmland soil mainly comes from organic fertilizers. Therefore, it is necessary to supplement the organic matter in the soil reasonably by using organic fertilizers according to the "appropriate value" of soil organic matter content and the consumption and transformation law of organic matter in the soil, so as to maintain the soil organic matter content at a relatively suitable level. For example, the suitable value for organic matter content in the topsoil of open dry land with relatively high terrain is 1.8-2.3%, the suitable value for organic matter content in open dry land on low flat land should be 2-2.5%, the suitable value for organic matter content in paddy field soil is 2-3%, and the suitable value for organic matter content in protected land soil is 3-5%. At present, only 25% of the soil in open-pit farmland can meet the appropriate value requirements for organic matter content, while more than 50% of the soil in protected areas has exceeded the appropriate value requirements, requiring reasonable allocation of organic fertilizers.
2. Emphasis should be placed on scientific fertilization, which should be based on the nutrient requirements of various crops, the actual fertilizer supply capacity of the soil, and the theory of nutrient return. The types and application methods of fertilizers should be reasonably determined, truly achieving the principle of "balanced fertilization" under the combination of organic fertilizer and chemical fertilizer. To improve the nutrient status of soil and prevent soil compaction and deterioration of soil physical and chemical properties through effective means such as rational cultivation.
3. Strictly control the use of toxic and harmful substances, and try to cut off pollution sources (such as sewage, Solid Waste, fertilizers, pesticides, and air dust) as much as possible. And reduce soil pollution through agricultural and biological measures (such as applying soil conditioners, biological agents, etc.), purify polluted soil, and reduce the toxicity of pollutants in the soil.
4. To achieve the integration of land use and maintenance, in the process of utilizing land, attention should be paid to the reasonable protection of arable land, so that our existing soil resources can permanently serve us as human beings.
In agricultural production, fertilization is an important factor affecting soil quality and crop growth. Reasonable fertilization is of great significance in improving soil quality, ensuring the normal growth and development of crops, and enhancing the quality of agricultural products.
2、 The Current Fertilization Issues in Agricultural Production
1. Unreasonable allocation of organic fertilizers: on the one hand, there are large areas of "white stubble land" (farmland that is not fertilized with organic fertilizers all year round), and on the other hand, excessive application of organic fertilizers. The amount of organic fertilizer applied in protected areas is relatively large, while in other areas, the farther away from the village, the less organic fertilizer is used. The level of organic matter content in soil largely reflects the level of soil fertility. A decrease in soil organic matter content means a decline in soil quality, an increase in soil dependence on fertilizers, and a decrease in the quality of agricultural products produced on the soil.
2. The degree of harmless treatment of organic fertilizers is not high: Organic fertilizers mainly come from various waste materials in agricultural production, including the excrement of various livestock and poultry. They contain various harmful bacteria and pollutants (harmful pathogens, toxic heavy metals, organic pollutants, certain special substances, and very unpleasant odors, etc.) inside. Before application, necessary harmless treatment processes need to be carried out. Otherwise, the harmful substances in these organic fertilizers can be directly brought into the soil, which may cause soil pollution and harm the normal growth of crop roots, increasing the negative effects of applying organic fertilizers. For example; Many livestock and poultry manure contain a substance called uric acid. When this substance decomposes in the soil, it is likely to cause damage to plant roots and harm crop growth. Therefore, necessary fermentation treatment is needed before use to decompose harmful substances in livestock and poultry manure, and reduce the toxicity of pollutants by changing the form of toxic substances. The main method for harmless treatment of livestock and poultry manure and urine is through a reasonable fermentation process. The fermentation process of livestock and poultry manure and urine is a biochemical reaction process that requires a certain amount of time to ensure. Rapid drying or drying through other physical factors cannot decompose harmful substances in livestock and poultry manure and urine. Directly drying livestock and poultry manure and urine as fertilizer carries great risks and is not worth promoting.
3. The variety of fertilizers is single, and the coordination between fertilizers is not given enough attention: for example, nitrogen fertilizers only focus on urea and ammonium bicarbonate, while phosphorus fertilizers only focus on diammonium phosphate, etc., which can easily cause nutrient imbalance in the soil, decrease fertilizer utilization efficiency, increase fertilizer costs, and soil compaction. Plant growth and development require more than ten types of nutrient elements. Every year during crop harvest, multiple nutrients must be taken away from the soil. In order to ensure the normal growth and development of crops in the following year and the balance of nutrient elements in the soil, it is necessary to supplement various nutrient elements in the soil through fertilization. If the type of fertilization is single and the proportion of nutrient elements is not paid attention to during fertilization, it will inevitably cause nutrient imbalance in the soil, affecting the growth of crops and the quality of agricultural products in the following year. The phenomenon of "food not fragrant, fruits not sweet, and vegetables not cooked properly" mentioned above occurs.
4. The application of trace element fertilizers lacks necessary soil testing and plant diagnosis, and is highly blind: the amount and method of application of trace element fertilizers are crucial. Plants are highly sensitive to various trace elements, and the boundary between deficiency and excess is narrow. If a certain trace element is lacking in the soil, plants will exhibit certain physiological diseases, such as small leaf disease in trees due to zinc deficiency, white seedlings in corn due to zinc deficiency, and seedling shrinkage disease in rice due to zinc deficiency. However, excessive application can immediately lead to plant poisoning. Even affecting the growth of crops for several years after the consensus of the following year. The key to rational application of trace elements is to test the physiological performance of crops in the field and the content of available trace elements in the soil.
5. Insufficient emphasis on the application of intermediate element fertilizers: Currently, many farmers in certain areas only focus on the application of nitrogen, phosphorus, potassium, and trace elements such as iron, manganese, copper, zinc, boron, and molybdenum, while neglecting the application of intermediate elements such as calcium, magnesium, and sulfur in production. As a result, the content of available intermediate elements in the soil is insufficient, and plants exhibit symptoms of intermediate element deficiency. For example, the occurrence of navel rot in tomatoes and chili peppers in agricultural production, as well as the occurrence of dry heartburn in Chinese cabbage, are all manifestations of plant calcium deficiency; The unclear yellowing of lower leaves in plants is a manifestation of magnesium deficiency; Unknown yellowing of upper leaves or young shoots in plants is a manifestation of sulfur deficiency, and so on. In production, it is necessary to supplement some moderate element fertilizers according to the needs of crops.
6. Insufficient emphasis on beneficial elements in plants: Some elements, although not essential for plant growth and development, are still beneficial elements for plant growth and development. There are many beneficial elements required for plant growth and development, such as silicon, cobalt, selenium, nickel, strontium, sodium, etc. Moderate supplementation of beneficial elements for plant growth and development plays an important role in improving crop quality, such as selenium. Some people predict that after China's accession to the WTO, seven types of agricultural products will have good prospects (sweet potato tender leaves, selenium rich agricultural products, specialty sweet potatoes, specialty corn, specialty fresh dates, specialty vegetables, and Ganoderma lucidum products), among which selenium rich agricultural products are one. China is located in a selenium deficient zone in the soil, where plants have limited availability of selenium. Relying solely on selenium in the soil makes it difficult to produce selenium rich agricultural products. To produce selenium rich agricultural products, it is necessary to cultivate selenium rich varieties and supplement plants with selenium containing fertilizers to compensate for the selenium deficiency. This can lead to the production of selenium rich vegetables and grains, such as selenium rich rice, soybeans, apples, strawberries, etc., in order to improve the quality of agricultural products and increase the competitiveness of China's agricultural products in the international market.
7. Improper use of fertilizers leads to low utilization efficiency: The high or low utilization efficiency of fertilizers closely affects the cost of fertilization and the pollution it causes to the environment. Improper fertilization methods, such as surface application of nitrogen fertilizer, flushing of fertilizer with water, unreasonable combination of fertilizers, blindly imitating others' fertilizer usage while ignoring the soil's own characteristics, etc., are the main reasons for low fertilizer utilization efficiency. At present, the utilization rate of nitrogen fertilizer in the soil of vegetable protection areas is very low, with only about 10% utilization rate in some places, which seriously wastes fertilizer resources and causes serious pollution to the soil and environment. For example, the nitrate nitrogen content in the soil of protection areas is significantly high, which has led to serious exceedance of nitrate in vegetables; The groundwater in concentrated protected areas has shown significant eutrophication. The current protected soil requires a multifunctional and regulating fertilizer.

8. In the process of selecting compound fertilizers, there is a lack of necessary understanding of the nutrient ratio, nutrient content, and nutrient types of fertilizers. Currently, there are many so-called compound fertilizer varieties with poor quality on the market. If not selected properly, it not only affects crop growth and agricultural product quality, but may also cause nutrient imbalance in the soil. For example, some compound fertilizers are a type of chlorine based compound fertilizer with an internal chlorine content of over 15%, which can cause serious harm to some chlorine sensitive crops such as tobacco, sugar beets, grapes, potatoes, etc.
9. Replacing nitrogen, phosphorus, and potassium fertilizers with biological fertilizers, trace element fertilizers, and foliar fertilizers: Strictly speaking, biological fertilizers are only biological agents (bacteria, actinomycetes, or other compound bacteria), and they do not contain the nutrients needed for plant growth and development (unlike organic compound fertilizers). When applied to the soil, only under appropriate conditions can microorganisms further grow and reproduce, improving and regulating the nutrient status of the soil through their series of life activities. Therefore, the fertilizer effect of biological fertilizers in agricultural production is not stable. Trace element fertilizers can only supplement the trace elements needed by plants. Foliar fertilizer can only be used as an auxiliary means of normal fertilization and cannot replace the fertilization of plant roots.
10. When fertilizing, soil properties are often overlooked: soil properties closely affect fertilizer effectiveness and crop growth. For example, some crops have a preference for acidity (strawberries, potatoes, scallions, garlic, chili peppers, rice seedlings, carrots, various flowers, etc.), so fertilizers that can release or produce acidity (ammonium sulfate, superphosphate, etc.) should be selected. Rice seedbed conditioners are also suitable for use on these acid loving plants. Some fertilizers prefer alkalinity, so it is advisable to use fertilizers that are slightly alkaline (sugar beets). Saline alkali land should use less fertilizers containing chlorine.