Impact of contour hedgerows on upland maize yields in the Philippines

Abstract

An agricultural production function is used to examine the yield impacts of contour hedgerows constructed using double rows of the N2-fixing species Desmodium rensonii and Flemengia macrophylla. The analysis uses data from a sample of upland Philippine maize farms and controls for input use and plot characteristics. Results support a hypothesis that the long-run impact of hedgerows on maize yields is positive. However, results suggest that in the short run, hedgerows not only reduce area available for cultivation on a plot, but also reduce the performance of corn in the remaining alleys. For newly established hedgerows an increase in hedgerow area is associated with a reduction in maize yield. The time required for hedgerows to compensate for the area they occupy is found to be approximately eight years.