Agroforestry and Grass Buffer Effects on Microclimate of a Corn-Soybean Rotation.
Ranjith P. Udawatta1, Neil I. Fox2, Peter P. Motavalli2, and Kelly Nelson3. (1) Center for Agroforestry, 203 ABNR, University of Missouri, Columbia, MO 65211, (2) Dept. of Soil, Environmental and Atmospheric Sciences, University of Missouri, 302 ABNR Bldg., Columbia, MO 65211, (3) Division of Plant Sciences, University of Missouri, Greenley Research Center, PO Box 126, Novelty, MO 63460
Agroforestry and grass buffers have been shown to improve water and soil quality and provide additional income. Microclimatic differences due to adoption of these practices may influence evapotranspiration and soil and biological properties within a watershed. The objective of this study was to quantify agroforestry (grass + tree) and contour grass buffer effects on microclimatic parameters in agricultural watersheds. The study was conducted at the University of Missouri Greenley Research Center in northeastern Missouri. The study site consists of three adjacent watersheds planted in a corn-soybean rotation. In 1997, cool season grass contour buffers were established in one watershed area and agroforestry buffers in another. The buffer dimensions were three to four m wide at 35 to 50 m intervals perpendicular to the slope of the watershed. Wind, temperature, humidity and radiation sensors were installed in 2006 to collect measurements at 10 minute intervals. Wind speed over the crop at the start of the measuring period was lower between the tree buffers than between the grass buffers. The mean wind speed between the agroforestry buffers for the ten day period from Julian day 161 to 170 was 2.25 m/s, while that between the grass buffers was 2.53 m/s. The difference due to agroforestry and grass buffers on wind, temperature, and solar radiation diminished as the corn grew taller. Further studies will investigate whether the observed decrease in wind speed causes reduced evapotranspiration in the agroforestry buffers and in the adjoining cropped areas.