5.4 Impact of Agricultural practices

Monocropping

Growing one single species (corn, wheat, soy) of crop ○ Highly efficient for harvest, pesticide and fertilizer application

impacts of monocropping

Greatly decreases biodiversity (more prone to pests, fewer nat. predators) - Increases soil erosion (crops harvested all at once & soil left bare) - Decreases habitat diversity for species living in the area

Tilling

Mixing and breaking up soil to make planting easier ○ Also loosens soil for roots

Impacts of tilling

Increases erosion by loosening topsoil, breaking up leftover root structure from harvest - Loss of organic matter & topsoil nutrients over time - Increased PM in air (rerp. irr) and sediments in nearby water (turbidity)

Slash and burn

Cutting down vegetation and burning it to clear land for ag. & return nutrients in plants to soil

Impacts of slash and burns

Deforestation - Loss of: habitat, biodiv, CO2 sequestration (storage), loss of air pollution filtration - Releases CO2, CO, N2O - all GHGs that lead to global warming - Increases PM in air (asthma) - Lowers albedo, making area warmer

Synthetic (inorganic) Fertilizers

Don’t return organic matter to soil; no increased H2O holding cap. & no soil decomposers, cause leaching.

Leaching

water carries excess nutrients (nitrates & phosphates) into groundwater or into surface waters (as runoff)