Importance Of Soil Microorganisms To Soil And Crops in The Greenhouse

Importance of soil microorganisms to soil and crops in the greenhouse

Soil microorganisms are the core components of the soil ecosystem and play an irreplaceable role in soil health and crop growth. The following are their main functions and the impact of their loss:
1. The core role of soil microorganisms 1. Organic matter decomposition and nutrient cycling - Decompose animal and plant residues and litter, releasing nutrients such as nitrogen, phosphorus, and potassium (such as cellulose-decomposing bacteria and nitrogen-fixing bacteria). - Convert organic matter into humus to improve soil fertility.
2. Improve soil structure - Microbial secretions (such as polysaccharides) act as "glue" to bind soil particles, forming a granular structure that enhances air permeability and water retention. - Prevent soil compaction and promote root extension.
3. Plant growth promotion - Symbiotic nitrogen fixation (such as rhizobia and legumes) directly provides nitrogen. - Synthesizes plant hormones (such as IAA, gibberellins) to stimulate root development. - Dissolves insoluble minerals (such as phosphate-solubilizing bacteria release phosphate).

4. Biological control and stress resistance - Antagonize pathogens (such as Trichoderma inhibiting Fusarium) to reduce soil-borne diseases. - Induce plant systemic resistance (ISR) to enhance drought and salt resistance.
5. Pollution remediation and ecological balance - Degrade pesticide residues (such as organophosphorus degrading bacteria) and petroleum pollutants. - Maintain the diversity of soil microbial communities and buffer environmental changes.
2. Consequences of the disappearance of soil microorganisms 1. Nutrient depletion and soil impoverishment - Organic matter accumulates and cannot be decomposed, plants cannot obtain nutrients and rely on artificial fertilization. - Long-term imbalance of soil carbon-nitrogen ratio, similar to the desertification process.
2. Deterioration of soil physical properties - The aggregate structure collapses, the soil hardens, the air permeability decreases, and the roots rot due to lack of oxygen. - The water retention capacity is lost, and the risk of drought and waterlogging increases.
3. Crop production collapses - The nitrogen fixation effect disappears, and leguminous crops cannot grow; other crops are completely dependent on chemical fertilizers, and the cost increases dramatically. - The obstacles to continuous cropping are aggravated, and soil diseases break out (such as wilt and root rot are out of control).

4. Chain reaction of ecosystems - Accumulation of litter on the ground affects seed germination and seedling growth. - Soil animals (such as earthworms) disappear due to the breakdown of the food chain, and ecological functions are further degraded.
5. Loss of agricultural sustainability - Traditional composting is ineffective, relying on chemical fertilizers and pesticides, and increasing pollution. - The land is gradually abandoned, which may eventually lead to a global food crisis.
3. Comparison of typical cases - Normal soil: 1 hectare of healthy soil contains about 5 tons of microbial biomass, which decomposes dozens of tons of organic matter every year and supports high crop yields. - Sterile soil: Experiments show that the biomass of corn in sterilized soil decreases by 70%, and an additional 200% of nitrogen fertilizer is required to reach normal levels
Soil microorganisms are the "invisible engineers" of terrestrial ecosystems. Their absence will lead to the complete paralysis of soil functions and the collapse of agricultural production systems. Protecting soil microbial diversity (such as reducing tillage, crop rotation, and applying organic fertilizers) is a core strategy for sustainable agriculture.