Soil Structure Development in Prairie Restoration

Period: January 30, 2005 – April 15, 2010
Contact: Ranjith Udawatta, Stephen Anderson, Harold Garrett
Organization: the University of Missouri
Funding Source: Prairie Fork Trust

Objectives: Prairie ecosystem restoration usually improves water infiltration and reduces runoff. One reason for these changes is hypothesized to be increased soil porosity, especially soil macropores. The proposed study will evaluate distributions of macropores and coarse mesopores as influenced by prairie restoration. A new method using X-ray computed tomography (CT) was recently developed to evaluate distribution of pores with higher resolution. Results from this proposed study can be demonstrated at on-site field days and at workshops.

The specific emphasis area of “soil characteristics/soil history at PFCA” is the focus of this study. Results from the proposed study will generate information to characterize soil pores which are highly correlated with infiltration and runoff that affect sediment, nutrient, and herbicide losses. It is anticipated that the results would help generate data for designing better systems to improve soil and water quality with incorporated prairie systems.

Previous research has shown that restoration of prairies improves soil carbon accumulation and diversity of soil microbial communities. Research has not been conducted on evaluating changes in soil pore sizes as influenced by prairie restoration and subsequent effects on runoff and water quality. Naturally, movement of infiltration water under ponded conditions follows the path of least resistance which is related to soil macroporosity. The proposed study will quantify changes in macropores and coarse mesopores using computed tomography due to prairie restoration. The study will also compare pore size differences among row-crop management, a mature prairie and two sites with different stages of prairie development.

The PFCA is an ideal site for this study as it has sites with different stages of prairie development and it is surrounded by crop land. This will allow us to minimize the variability due to differences in soils, aspect, precipitation and crop rotation.