1. Soil & Plant Nutrition 37

2. Soil contains a living, complex ecosystem Varies from coarse sand to clay Physical & chemical properties of soil – Bacteria, fungi, algae, protists, insects, worms, nematodes, and plant roots Most fertile soils are loams – Equal parts sand, silt, clay – Adhesion & cohesion of minerals and water

3. Soil conservation & Sustainable Agriculture Fertilization can make soil a renewbale resource  soil management Mismanagement  American dust bowl in the SW USA – Dust storms resulted in decades of rpolonged drought & decades of bad farming techniques Sustainable Agricultire – Conservation & solving soil degradation

4. Irrigation Erosion – Water & wind – Carry away minerals Fertilization – Addition of minerals from depletion – NPK  15%-10%-5% Soil pH – Influences cation exchange & minerals