I. Environmental Benefits

1. Pollution Reduction and Waste Mitigation
   Direct incineration or landfilling of plant residues (e.g., crop straw, fallen leaves, fruit peels) releases greenhouse gases like CO₂ and methane, or hazardous substances such as dioxins. Composting avoids these pollutants while alleviating pressure on landfills.
   Example: China generates approximately 900 million tons of crop straw annually; full utilization for composting could significantly curb air pollution caused by straw burning.

2. Decreased Reliance on Chemical Fertilizers
   Substituting organic fertilizers for part of chemical fertilizers reduces energy consumption and carbon emissions during fertilizer production. Statistics show that producing 1 ton of chemical fertilizer emits roughly 1.5 tons of CO₂, whereas organic fertilizer production generates negligible additional emissions.

3. Carbon Sequestration Promotion
   Carbon in plant residues is converted into stable humus through composting, enabling long-term storage in soil and mitigating climate change. Studies indicate that each ton of organic fertilizer can sequester approximately 0.3 tons of carbon.

II. Agricultural Benefits

1. Soil Structure Improvement
   Organic fertilizers, rich in organic matter, enhance soil porosity, aeration, and water retention, reducing compaction and erosion risks. For instance, after three years of continuous application, soil bulk density can decrease by 10%–20%.

2. Enhanced Soil Fertility
   Organic fertilizers slowly release nutrients like nitrogen, phosphorus, and potassium, preventing nutrient loss and soil acidification caused by chemical fertilizers. They also provide carbon sources for soil microbes, boosting microbial diversity and ecological functions.
   Experimental data: Soil microbial biomass carbon under organic fertilizer treatment is 30%–50% higher than that under chemical fertilizer treatment.

3. Strengthened Crop Resilience
   Beneficial microbes in compost inhibit pathogens, reducing pest and disease incidence. For example, actinomycetes in compost secrete antibiotics that lower soil-borne disease rates. Organic fertilizers also improve crop drought and cold tolerance, cutting pesticide use.

4. Improved Agricultural Product Quality
   Organic fertilizers facilitate trace element absorption, enhancing fruit sugar content, vitamin levels, and flavor. Case study: Strawberries grown with organic fertilizers exhibit 15%–20% higher soluble solids content than those grown with chemical fertilizers.

III. Economic Benefits

1. Reduced Production Costs
   Farmers can produce organic fertilizers locally using plant residues (e.g., straw, livestock manure), slashing chemical fertilizer purchases. Estimates suggest savings of ¥50–100 per mu (≈0.07 hectares) from organic fertilizer use.

2. Increased Added Value of Agricultural Products
   Crops grown with organic fertilizers meet green food standards, fetching 20%–50% higher market prices than conventionally grown produce, thereby boosting farmer incomes.

3. Job Creation
   Organic fertilizer production, transportation, and sales generate rural employment, driving circular economy development. Example: A medium-sized organic fertilizer plant can employ 20–50 workers.

IV. Social Benefits

1. Sustainable Development Promotion
   Organic fertilizer production aligns with the "reduce, reuse, recycle" principles of circular economy, supporting China’s 14th Five-Year Plan for Green Agricultural Development, which targets 50% organic fertilizer application coverage by 2025.

2. Public Health Enhancement
   Reduced chemical fertilizer and pesticide use lowers agricultural residue risks, ensuring food safety. Long-term application of organic fertilizers also decreases heavy metal content in grain compared to chemical fertilizer treatments.

3. Ecological Education Advancement
   The composting process serves as an educational case study, raising public awareness of resource recycling and ecological conservation.

V. Technological Advantages

1. Simple Operation and Strong Adaptability
   Household composting (e.g., Bokashi method) requires no complex equipment, suitable for small-scale farmers; industrial composting (e.g., trough fermentation) efficiently processes large-scale waste with high productivity.

2. Balanced Nutrient Release and Long-Term Efficacy
   Nutrient release from organic fertilizers synchronizes with crop demand, minimizing loss and improving utilization. Studies show nitrogen utilization rates for organic fertilizers are 10%–15% higher than those for chemical fertilizers.