Chemically, soil organic matter affects the cation exchange capacity, provides nutrients, and affects the capacity for buffering changes in soil pH. These in turn affect the fate and transport of chemicals including nutrients and pollutants. Recommended levels of organic matter are 2-8 percent by weight. Organic matter from both grass and peat reduced bulk density and increased moisture retention. While organic matter from grass increased soil shear strength from 19.17 to 24.44 kN m−2, that from peat reduced it from 15.47 to 11.90 kN m−2. Physically, organic matter influences soil structure and all associated properties. Chemically, soil organic matter affects the cation exchange capacity and the capacity for buffering changes in soil pH. Biologically, organic matter acts as the nutrient and energy supply for microbial biomass and higher plants. Organic matter is particularly important as the prime habitat for immense numbers and variety of soil fauna and microflora, which play a critical role in the health and productivity of soils. Organic matter increases a soil's ability to hold water, both directly and indirectly. Compaction increases bulk density and reduces total pore volume, consequently reducing available water holding capacity. Organic matter causes soil particles to bind and form stable soil aggregates, which improves soil structure. With better soil structure, water infiltration through the soil increases and improves the soil's ability to absorb and hold water as well as reduces the potential for surface crusting of the soil.

Soil organic matter significantly improves the soil's capacity to store and supply essential nutrients and to retain toxic elements. It allows the soil to cope with changes in soil acidity, and helps soil minerals to decompose faster. The effect of organic matter is to reduce bulk density and increase moisture retention, both of which act to reduce soil shear strength. On the other hand, organic matter generally increases the ability of the soils to hold moisture, expands the available water capacity, increases the saturated conductivity and decreases the penetration resistance of compacted soils. Soil strength will influence aggregate stability and soil structure. High soil strength, depending on where in the soil profile, can: Inhibit seedling emergence and limit root penetration. Chemically, soil organic matter affects the cation exchange capacity, provides nutrients, and affects the capacity for buffering changes in soil pH. These in turn affect the fate and transport of chemicals including nutrients and pollutants. Recommended levels of organic matter are 2-8 percent by weight. The cone test determines the soil strength from the force used to push a cone into the soil sample and the penetration depth at a specified angle. Vane shear test uses a vane to penetrate the cylindrical-shaped soil sample. Soil strength is determined by the applied torque that causes material failure. A uniform soil has more strength and stability than a non-uniform soil.

In fact on the other hand, organic matter generally increases the ability of the soils to hold moisture, expands the available water capacity, increases the saturated conductivity and decreases the penetration resistance of compacted soils. The effect of organic matter is to reduce bulk density and increase moisture retention, both of which act to reduce soil shear strength. Chemically, soil organic matter affects the cation exchange capacity, provides nutrients, and affects the capacity for buffering changes in soil pH. These in turn affect the fate and transport of chemicals including nutrients and pollutants. Recommended levels of organic matter are 2-8 percent by weight. Soil organic matter significantly improves the soil's capacity to store and supply essential nutrients and to retain toxic elements. It allows the soil to cope with changes in soil acidity, and helps soil minerals to decompose faster. Organic manure has the tendency to improve soil physical properties through increased soil aggregation, decrease in the volume of micropores while increasing macropores, increased saturated hydraulic conductivity and water infiltration rate thereby improving soil water-holding capacity at both field capacity. Physical properties also influence the chemical and biological behavior of soil. The physical properties of a soil depend on the amount, size, shape, arrangement and mineral composition of its particles. These properties also depend on organic matter content and pore spaces.