Soil and Water Conservation
Soil and water conservation is the science and practice of protecting soil from erosion and degradation and managing water for sustainable land use, safeguarding the productivity of the land.
Definition
Soil and water conservation comprises the principles and practices for preventing soil erosion and degradation and for managing water so that land remains productive and the soil and water resources are sustained.
Scope
This area covers the processes of soil erosion by water and wind, the practices used to control erosion and conserve soil and water, the management of irrigation and drainage, and the degradation and restoration of soils. It applies soil physics, chemistry, and biology to the practical goal of sustaining the soil and water resource.
Sub-topics
Core questions
- How do water and wind erode soil, and what controls the rate?
- What practices control erosion and conserve soil and water?
- How are irrigation and drainage managed sustainably?
- How are degraded soils restored?
Key concepts
- Water and wind erosion
- Rainfall erosivity and soil erodibility
- Universal Soil Loss Equation
- Conservation practices and tillage
- Irrigation and drainage management
- Soil degradation and restoration
Key theories
- Universal Soil Loss Equation
- The Universal Soil Loss Equation estimates long-term average soil loss from the product of rainfall erosivity, soil erodibility, slope length and steepness, cover and management, and support practices, providing a quantitative basis for conservation planning.
- Conservation management of soil and water
- Erosion and degradation can be reduced by maintaining cover, building soil structure and organic matter, and controlling water flow, integrating agronomic, structural, and biological measures.
Clinical relevance
Soil and water conservation protects the long-term productivity of agricultural land, reduces sedimentation and nutrient pollution of waterways, sustains water supplies, and helps maintain soil carbon; it is fundamental to food security and environmental quality, especially under intensifying land use and climate change.
History
Soil conservation emerged as a discipline after the Dust Bowl of the 1930s, led in the United States by Hugh Hammond Bennett and the new Soil Conservation Service. The development of the Universal Soil Loss Equation in the mid-20th century gave conservation planning a quantitative tool, and the field has since broadened to encompass water management, degradation, and restoration.
Key figures
- Hugh Hammond Bennett
- Walter H. Wischmeier
- Rattan Lal
Related topics
Seminal works
- wischmeier1978
- brady2016
- lal2004
Frequently asked questions
- Why is soil erosion such a serious problem?
- Erosion removes the fertile topsoil that took centuries or millennia to form, reducing productivity, and the eroded sediment and attached nutrients pollute rivers and reservoirs; because soil forms so slowly, losses far outpace natural replacement and the damage is effectively permanent on human timescales.
- What are the main ways to conserve soil and water?
- Key measures include keeping the soil covered with residue or vegetation, reducing tillage, contour and terrace practices that slow runoff, building soil organic matter and structure, and managing irrigation and drainage efficiently, often combined to suit local conditions.