Plants provide the carbon and food source for soil organisms that bind the soil particles into aggregates and recycle soil nutrients, and soil provides the habitat, water, and mineral nutrients for both soil organisms and plants. Any factor or soil management technique that changes the amount and quality of carbon going into the soil as either residue or root exudates will effect change in the soil biological community. Change which ultimately has consequences for plant growth. Once again, putting emphasis on the interconnectedness between all farming practices and the soil. Management practices that affect the placement and incorporation of residues can make it harder or easier for the soil organisms responsible for recycling nutrients.
Tillage directly affects soil porosity and the placement of residues.
Porosity determines the amount of air and water the soil can hold. Placement of residues affects the soil surface temperature, rate of evaporation and water content, and nutrient loading and rate of decay. In other words, tillage collapses the pores and tunnels that were constructed by soil animals, changing the water holding, gas, and nutrient exchange capacities of the soil. Conservation tillage and particularly no tillage reduce soil disturbance, increase organic matter content, improve soil structure, buffer soil temperatures, and allow soil to catch and hold more melt water. These soils are more biologically active and biologically diverse, have higher nutrient loading capacities and release nutrients more continuously.