Compost enhances soil fertility by enriching it with organic matter, which improves nutrient retention and provides a steady release of essential elements like nitrogen, phosphorus, and potassium while stabilizing soil pH and reducing nutrient loss. In contrast, inorganic fertilizers supply nutrients rapidly but may degrade soil health over time by reducing microbial activity and increasing compaction. The most effective strategy is to combine compost with inorganic fertilizers—compost offers sustained nutrient availability and supports microbial growth, while fertilizers give an initial nutrient boost. This synergy boosts soil carbon, improves post-harvest nutrient levels, and enhances crop performance, as seen in rice, wheat, and maize fields where compost-fertilizer blends increase nitrogen availability and promote healthier soils.

Beyond fertility, compost improves soil structure and water-holding capacity, acting like a sponge—particularly beneficial for sandy soils. For instance, integrating water hyacinth compost with chicken manure in spinach cultivation increases leaf area by providing an early nutrient surge from manure and a prolonged release from compost. Compost also creates a balanced microbial environment, with bacteria spreading evenly and fungi clustering due to nutrient enrichment, although drastic moisture changes can reduce microbial activity. Additionally, compost lowers soil bulk density, improving aeration and root penetration, which enhances nutrient and water uptake. Unlike compost, inorganic fertilizers do not improve water retention and may even compact soil. Combining the two enhances moisture retention and structural stability, optimizing plant growth. Testing different ratios through optimization and microbial profiling helps determine the most effective blend for sustainable agriculture (reference: Optimizing Water Hyacinth Compost and Chicken Manure for Enhancing Spinach Growth: An Eco-Friendly Approach to Sustainable Agriculture).

Crop resilience depends on both plant variety and active soil microbes, which are sensitive to stresses like drought. Compost strengthens plants by fostering root development, nutrient absorption, and microbial activity, while also improving protein content through macronutrient support. This resilience is especially crucial during drought when inorganic fertilizers fail to benefit crops in the absence of moisture. While fertilizers may promote rapid initial growth, they can harm soil life and reduce long-term productivity. An integrated compost-fertilizer approach enhances yield stability and helps crops endure stresses such as drought and heat. For example, spinach grown with water hyacinth compost and chicken manure demonstrates vigorous, sustained growth, showing how this strategy supports both soil health and crop productivity under challenging conditions.

Compost combined with inorganic fertilizers improves soil fertility and water-holding capacity (WHC) more than either input alone by building organic matter, improving aggregation and cation-exchange capacity, and buffering nutrient supply; integrated application can sustain yields while reducing reliance on chemical fertilizer, enhancing drought resilience and stabilizing crop performance through improved soil physical and biological properties.

Soil fertility is based the most on microbe activities. Their life depend essentially on a good argilo-humique complex. The compost gives organic matter to maintain these activities and help to reduce damages induced by mechanization.

Compost is store- house of nutrients which are essential for plants.Water holding capacity of soil is increased by compost.Compost help the maintain granular condition,granular condition of soil maintains favourable condition of aeration and permeability.Compost on the upper surface of the soil reduces the temperature of soil in summer and maintains hot in winter.compost increases the cohesion,adhesion,plasticity like properties in sandy soils and reduces these properties in clay soils.Thus physical,chemical and biological properties of soil improves by combined application of compost with inorganic fertilizers.

There is no doubt that Recommended dose of inorganic fertilizers with compost in the form of vermicompost, biomanure,farm yard manure (FYM) may be quite effective. But imbalanced dose of inorganic fertilizers is not good. In the present scenario, imbalanced use of chemical fertilizers reduce the fertility power of the soil in slow motion and therefore, farmers should be used biocompost which having useful components and useful microorganisms to better growth and development of the crops/green plants.