Monitoring Water-Quality Response of Conservation Practices in the Bucks Branch Watershed, Sussex County, Delaware

Science Center Objects

The Bucks Branch sub watershed in the Nanticoke River basin has been identified as having one of the highest concentrations of nitrate in surface water of all sites sampled in Delaware. 

Changes in water quality related to changes in agricultural conservation practices will be seen first in shallow groundwater as groundwater is the major source of nitrate in surface water. 

Very little research is available on the effectiveness of agricultural conservation practices in reducing the leaching of nitrate into groundwater. 

Irrigation is being considered as a conservation practice because more efficient use of nitrogen under irrigated land is hypothesized to lower the amount of residual nitrogen in soil available that would eventually leach to groundwater. There is also a need to understand the time-frame of stream response to changes in groundwater quality.

Objectives

(1) Study and compare the effects of irrigated and dryland farming with manure application along a flowpath from the soil/vadose zone, through the groundwater system to the stream.

(2) Characterize stream water quality and to improve understanding of the water-quality response of streams to changes in agricultural practices and climate variability.

Approach

Data will be collected at several hydrologic scales from soil and vadose zone, to shallow groundwater, along groundwater flow paths, in small-order streams, and at the local watershed outlet. Data on past cropping practices, irrigation efficiency, plant uptake, and soil nitrogen and phosphorus levels collected by University of Delaware for a concurrent study at this site will also be available.

Publications

 An SIR will be prepared for the cooperator summarizing the results of this project. Project data will also be combined with results from the parallel Andover project in Maryland and prepared as a journal article focusing on the efficacy of irrigation as a conservation practice.