Soil Organic Matter
Managing soil organic matter is the key to air and water quality (Figure 1).
Erosion control is not enough
Soil conservation policy in the United States stems from the devastating erosion
events of the 1920s and í30s. Out of concern for preserving agricultural
productivity came the concept of tolerable soil loss and the creation of the T
factor, which is the maximum annual soil loss that can occur on a particular soil while
sustaining long-term agricultural productivity. Conservationists focused on
reducing soil loss to T by applying practices, such as terraces, contour strips,
grassed waterways, and residue management.
By the end of the twentieth century, concerns about air and water quality became as
important as concerns about agricultural productivity. To address these
environmental goals and maintain the landís productive potential, we must now go
beyond erosion control and manage for soil health. How soil functions on every
inch of a farm, not just in buffers or waterways, affects erosion rates,
agricultural productivity, air quality, and water quality. The most practical
way to enhance soil health today is to promote better management of soil
organic matter or carbon. In short, we should go beyond T and manage for C
Why focus on soil organic matter?
Many soil properties impact soil health, but organic matter
deserves special attention. It affects several critical soil functions, can be
manipulated by land management practices, and is important in most agricultural
settings across the country. Because organic matter enhances water and nutrient
holding capacity and improves soil structure, managing for soil carbon can
enhance productivity and environmental quality, and can reduce the severity and
costs of natural phenomena, such as drought, flood, and disease. In addition,
increasing soil organic matter levels can reduce atmospheric CO2 levels that
contribute to climate change.
|Figure 1. Best Management Practices can increase soil organic matter and enhance
health, positively affecting air and water quality and soil productivity.
> Go to "Go Beyond T - Manage for C"