the soils around us. soils and ecosystems in crisis “the coming 50 years are likely to be the...
TRANSCRIPT
The Soils Around Us
Soils and Ecosystems in Crisis
• “The coming 50 years are likely to be the final period of rapidly expanding, global human environmental impacts. Future agricultural practices will shape, perhaps irreversibly, the surface of the Earth, including its species, biogeochemistry and utility to society”
• Agricultural use of soil systems faces challenges:
– Need for increased production per hectare
– Need to reduce environmental footprint
• Fertilizer use and loss
• energy
– Resist land loss by erosion, urbanization, etc.
World Food Production
• Maintained pace due to inputs of energy and mass
World Food Production
• Pace and efficiency are declining with time
World Food Production
• Pace and efficiency are declining with time
• The fundamental resource (soils) are declining with time
Functions of soils in ecosystems
Biologically Essential Elements
Soils as an Environmental Interface
The Soil System
• 3d component of Earth surface
• Dimensions a human construct
• System allows us to quantify inputs, outputs, and changes
• Soil system is a component of eocsystems
The Soil System
• Dynamic with time
• Properties depend on state factors
The Soil System
• Result of combination of factors is unique soil
• Horizons and other properties depend on state factors
BIOTA CLIMATE
PARENT
MATERIAL
TOPOGRAPHY
TIME
Soil Horizons/Profile
Importance of Knowledge of Whole Soil
Soil Composition
• solids
• gases
• water
• life
Soil pH
Soil Particle Sizes
Nutrient Sources in Soils