Evaluating Soil Organic Matter and Soil Biology for Improving Short- and Long-Term Management of Soil Nitrogen Supplying Capacity

Evaluating Soil Organic Matter and Soil Biology for Improving Short- and Long-Term Management of Soil Nitrogen Supplying Capacity

Summary

This proposal requests SARE program funding to investigate the relationship between soil management practices, soil organic matter (SOM) characteristics and dynamics, soil biology and soil nitrogen (N) fertility. Our project is a collaborative effort between members of a grass roots farmers organization, Innovative Farmer of Ohio (IFO), and the Ohio State University. The collaborating farmers are participating in the identification, development and testing of innovative technologies and management strategies that optimize and reduce N fertilizer inputs. Their approach is to evaluate and use on-farm N resources more efficiently, and base the use of purchased N inputs on more complete information about SOM and its relationship to soil biology and soil N supplying capability.

This research will generate a better understanding of the biological basis for N fertility (both short- and long-term) present in all soils, and explore methods to evaluate and manage this fertility. Specifically, the three objectives of this project are: 1) Demonstrate the degree to which particulate organic matter is affected by management alternative, including tillage and cultivation, cover cropping, animal manuring, and crop rotation; 2) Evaluate relationships between POM and soil biological activity; and 3) Relate POM quality and dynamics to N dynamics and availability, and evaluate the utility of POM measurements in predicting soil N availability for crop uptake.

Our approach represents a synthesis of practical on-farm, farmer-led research and basic ecological and agronomic lab and field research, and is guided by members of IFO and OSU researchers jointly identifying objectives and practical alternatives for investigation, and evaluating and applying the results in a broader farming system context. The results of this research will have practical implications in the short term for using on-farm and purchased N inputs more efficiently and, in the long term, for managing the soil’s inherit N supplying capacity. Results will be shared through IFO field days, farmer-to-farmer workshops and newsletters, as well as through popular and refereed publications. The project’s outcome will be evaluated in terms of the participating farmers’ ability to reduce fertilizer N costs through better evaluation, utilization and management of on-farm N resources.