How should you choose the most suitable fertilizer—chemical fertilizer, organic fertilizer, or bio‑fertilizer?

　　Fertilizing is a crucial step in farming, so choosing the right fertilizer and using it effectively is especially important. With so many types of fertilizers available on the market today, how do we select the one that best suits our needs? Let’s talk about fertilizers together!

　　Today, we’ll focus on the three most commonly used types of fertilizers: chemical fertilizer, organic fertilizer, and bio‑fertilizer. Some people say that combining organic fertilizer, chemical fertilizer, and bio‑fertilizer yields the best results. What do you think?

　　1. Organic Fertilizer: Organic fertilizer is a type of fertilizer primarily derived from plant and/or animal residues and manure, produced through biological fermentation. Its standard is NY 525–2012 issued by the Ministry of Agriculture. Key specifications include an organic matter content of ≥45% and nutrient levels of at least 5% for nitrogen, phosphorus, and potassium. These are the principal indicators. The main functions of organic fertilizer are to increase soil organic matter, promote microbial proliferation, enhance the soil’s physicochemical properties and biological activity, and improve the uptake of chemical fertilizers.

　　II. Inorganic Fertilizers: Inorganic fertilizers, also known as mineral fertilizers or chemical fertilizers, are produced through chemical synthesis. They include nitrogen, phosphorus, potassium, and compound fertilizers. Characterized by their simple composition, high content of available nutrients, rapid solubility in water, quick decomposition, and easy absorption by plant roots, they are commonly referred to as “fast-acting fertilizers.”

　　III. Bio‑fertilizers: Simply put, bio‑fertilizers are fertilizers that contain beneficial microorganisms. Their primary advantage lies in the functional microorganisms they harbor. There are three main types of bio‑fertilizers: microbial inoculants, compound microbial fertilizers, and bio‑organic fertilizers. Here’s an overview of the pros and cons of each.

　　1. Advantages of chemical fertilizers: high nutrient content and rapid effectiveness. Disadvantages: relatively limited nutrient profiles, typically consisting of one or three chemical elements; rapid nutrient release, leading to easy volatilization and leaching; and, with long-term, single‑crop use, nutrients may become fixed in the soil, resulting in resource waste and soil degradation, ultimately reducing crop yields and quality.

　　2. Advantages of organic fertilizers: They contain abundant organic matter and a wide range of nutrients essential for plant growth. Organic fertilizers effectively improve soil structure, increase the soil’s nutrient‑holding capacity, enhance its ability to retain nutrients and water, regulate soil pH, stimulate microbial activity, and boost the availability of soil nutrients. Disadvantages: They have low nutrient concentrations and release nutrients slowly, so their yield‑increasing effects are less pronounced than those of chemical fertilizers.

　　3. Advantages of microbial fertilizers: They can activate nutrients that have been immobilized in the soil, stimulate root growth and nutrient uptake, and reduce the amount of chemical fertilizer needed for those nutrients. In soil‑conditioning applications, the proliferation of beneficial microbial populations helps suppress harmful pathogens, thereby mitigating crop diseases. Disadvantages: They contain little or no nitrogen, phosphorus, or potassium, so they cannot provide a sustained supply of nutrients to crops over long periods. Because microbial fertilizers consist of live microorganisms, they are generally sensitive to direct sunlight and should not be mixed with pesticides. They also have relatively stringent requirements for environmental conditions such as soil temperature, moisture, pH, and organic matter content.

　　Having examined their respective advantages and disadvantages, we now turn to a detailed analysis of the benefits of using these three together: applying bio‑fertilizers increases the population of beneficial soil microorganisms, activates the soil, and enhances the efficiency with which soil nutrients are utilized. Bio‑fertilizers can act as catalysts in the microbial metabolic cycles of plants, promoting the formation of soil aggregate structures, improving internal porosity, boosting soil biological activity, and accelerating the release of readily available nutrients—thereby supporting root growth and strengthening the plant’s stress tolerance.

　　The synergistic effects of bio‑fertilizers and organic fertilizers are primarily manifested in:

　　1. Organic fertilizers supply organic matter, while biofertilizers provide beneficial microorganisms; moreover, organic matter serves as food for these microbes, and the more organic matter in the soil, the better the microorganisms can thrive.

　　2. Organic matter provides abundant nutrients for beneficial microorganisms, while these microorganisms accelerate the humification of organic fertilizers. When applied together, they mutually reinforce each other, complementing one another’s strengths and mitigating their weaknesses, thereby improving soil structure, enhancing soil aeration and water-holding capacity, boosting root absorption, and increasing fertilizer use efficiency, ultimately reducing the need for chemical fertilizers.

　　3. Organic fertilizers and microbial fertilizers complement each other in their mechanisms of action, and their combined use yields the greatest benefits. However, the macronutrients—nitrogen, phosphorus, and potassium—contained in these products alone cannot meet the nutrient requirements of crops throughout their entire growth cycle; therefore, supplementing them with chemical fertilizers would make the approach even more effective.

　　(Chemical fertilizers) Inorganic fertilizers are absorbed by crops indirectly through the decomposition and transformation of organic matter in the soil. Meanwhile, the increase in organic matter further enhances soil activity, providing a favorable environment for microbial survival and reproduction. In turn, the vigorous activity of these microorganisms reactivates the soil, establishing a positive feedback loop that is highly beneficial to soil health.

　　As organic matter increases, crops’ stress tolerance also improves. At the same time, residual inorganic phosphorus and potassium in the soil are converted into available forms that crops can readily absorb and utilize, thereby reducing the need for chemical fertilizers, enhancing fertilizer efficiency, and lowering costs. Applying chemical fertilizers in combination with organic fertilizers and bio‑fertilizers yields better results than using any one type alone. Therefore, to achieve optimal fertilization outcomes, a balanced combination of all three is recommended.