Chemistry and Biodegradability of Dissolved Soil Organic Matter in Diverse Farming Systems

View the project final report

Commodities

• Animals: poultry

Practices

• Animal Production: pasture fertility
• Crop Production: nutrient cycling
• Education and Training: decision support system
• Production Systems: organic agriculture
• Soil Management: nutrient mineralization, organic matter, soil analysis, soil chemistry, soil microbiology, soil quality/health

Soil quality has become a focal point for sustaining agricultural productivity in intensive and extensive agricultural practices.  While microbial biomass and mineralization of soil organic carbon and nitrogen are often-used biological parameters to evaluate soil quality, they are unlikely comprehensive to diagnose soil organic matter and microbially-mediated soil functions. Additionally, the parameter measurements are time consuming and labor intensive.  Mounting evidence supports that dissolved soil organic matter (DOM) contributes to numerous soil chemical, physical, and biological processes and, thus, may present a holistic picture on soil quality.  To date, there has been little information on the agricultural and ecological significance of DOM in diverse farming systems.  In this project we will: (1) assess the impacts of agricultural management on the quantity and chemical properties of DOM and (2) examine the relationships of DOM with other soil chemical and biological properties in a well-designed farming-systems unit that includes five systems: conventional farming, organic farming, integrated crop and livestock, plantation forestry, and agricultural field succession.  We anticipate that our investigation will lead to an enhanced appreciation of roles of DOM in critical soil processes that has practical ramifications on soil quality and agricultural production.

1. Quantify and characterize dissolved soil organic matter (DOM) in various farming systems.

2. Examine the relationships of DOM with key soil properties that are often used for evaluating soil quality, including soil organic matter, microbial biomass, soil respiration, and soil enzyme activity.