Soil Conservation and Restoration.  Soil degradation, through human activities and natural forces, has reduced the productivity of our soils and damaged adjacent ecosystems. Soil degradation can result from accelerated soil erosion, loss of vegetative cover, oxidation of soil organic matter, and impairment of soil physical, chemical and biological properties and processes. Worldwide, erosion by water, wind, tillage, and irrigation remains a major cause of soil degradation and a primary environmental concern. Poor land management can cause loss of soil organic matter; soil compaction; accelerated soil acidification; and buildup of salts, toxic trace elements and nutrients. Effective and economically-feasible management practices are needed to prevent soil degradation and to remediate degraded soils.

Nutrient Management.  Since the 1950s, nutrient management have changed from on-farm recycling of nutrients using animal or green manure to use of concentrated chemical fertilizers. However, fertilizer use-efficiency is commonly less than 50 percent in many agricultural systems. Application of excessive amounts of fertilizer or manure is one reason agriculture is the largest non-point source of pollution to surface and ground water. Economic use of renewable nutrient sources and improved nutrient use-efficiency in agricultural systems are problems that must be addressed. Research is needed to understand nutrient fate and transformations in soil so that management practices can be developed for sustainable production while protecting soil, water and air. Management practices to enhance soil carbon sequestration and improvement of soil properties and processes as a result of carbon sequestration are important topics of investigation in this program component.

Soil Water.  Water is the most limiting soil factor for crop growth and yield in most agricultural soils, accounting for approximately 80 percent of crop yield variability. Soil water, directly or indirectly, affects most soil physical, chemical and biological properties and processes. Most crop production problems associated with soil water relate to its supply and availability; infiltration adequacy and timing; and prevention, elimination, or mitigation of soil water excesses. Research will be conducted in this Program Component to understand soil properties controlling water movement into and through the soil with the goals of improving water relations in soils for enhanced crop production and to predict and manage transport of contaminants.

Soil Biology.  The living portion of the soil consists of plant roots and great numbers of remarkably diverse living organisms that are partially to totally invisible to the naked eye. Although the importance of these organisms is generally accepted, a greater understanding of their role in soil physical, chemical and biological properties and processes will be needed to manage this resource for the benefit of agricultural and other land uses. Research also will be needed to understand the basic ecology of soil organisms in bulk soil as well as in close proximity to plant roots and seeds. Other areas that will require investigation include: interactions between soil management practices and soil organisms; the role of soil organisms in controlling plant diseases, plant pests, and weeds; and the role of soil organisms in degradation of pesticides and other synthetic and natural toxins.

Productive and Sustainable Soil Management Systems.  Our focus in this component area will be to develop more sustainable soil management practices by using a systems approach to integrate principles of soil biology, chemistry, and physics into management practices that will optimize land use and be readily adopted by producers. Research in this area will include: developing innovative crop rotation, cover crop, and residue management strategies; providing site specific soil management practices to optimize soil biological, chemical, and physical properties and processes; and developing soil quality indicators and indices to assess the sustainability of soil management practices.