... 2 ,40 0 pounds of fungi, 1,500 pounds of bacteria, 133 pounds of protozoa, 890 pounds of arthropods and algae, and in some cases, small mammals (Sullivan, Preston “Sustainable Soil Management: Soil ... provides soils with the nutrients required by plants to grow • Organic matter also improves soil structure, and helps the soil to retain more water THE ISSUES “A nation that destroys its soils ... depletion and wide-scale soil erosion, over-application of fertilizers and pesticides have contaminated our soils and polluted our waterways SOIL EROSION • Erosion is the movement of soil by water, wind,...