Chapter five - A Decision Support Framework for Effective Design and Placement of Vegetated Buffer Strips Within Agricultural Field Systems

Abstract A prototype Decision Support System (DSS), Buffers DSS, is presented to aid effective design (e.g., width) and placement of vegetated buffer features within field systems. A modified version of the Morgan–Morgan–Finney erosion model was used to simulate the effects of vegetation and particle-size selectivity in the detachment, transport, and deposition of sediment within agricultural fields. Evaluation of the model concluded that stem diameter and density of plants in a buffer were key parameters affecting the trapping efficiency, while soil texture affected transmission distance and therefore required buffer width. The model output in combination with other evidence was used to produce a quick and easy look-up table to determine the required buffer width to prevent > 2 t ha −1  yr −1 of eroded soil from leaving a field, which ranges from  130 m width depending on soil type and % ground cover. This look-up table forms an integral part of the Buffers DSS. The Buffers DSS has been designed with end users in mind, specifically farmers and farm advisors. Thus, the Buffers DSS utilizes information already generated from agri-environment schemes and combines this information with quick and easy look-up tables that take into account site-specific soil texture, slope, and vegetation characteristics. The purpose of the Buffers DSS is to aid decision making. It provides guidance on the best locations in which to place vegetated buffer features, in order to optimize sediment and sediment-associated pollutant trapping, while also minimizing the area of land that is removed from agricultural production.