Bruner Farm Study for Resilient Economic Agricultural Practices in Ames, Iowa
Soil P analyzed by Bray P extractant. Soil K analyzed by Ammonium Acetate extractant. For MeasSoilCover estimates: Photos were taken with a Canon, 12.3 megapixel EOS Rebel T3 mounted on a Van-Guard QS-46 large format quick shoe. The monopod that the amera/shoe assembly was attached to is a Wooster Sherlock model R056 telescoping pole. A mounting racket and spirit level (part #’s MSRMB and MSRSLA respectively, available from Cropscan inc. http://www.cropscan.com/mpscs.html) were attached to the pole in a manner so that when the camera is mounted, and the bubble in the spirit level is centered, then the focal plane of the camera is perpendicular to the ground resulting in a nadir image of the ground beneath the camera. The fully extended pole camera assembly was carried diagonally across each plot in field 70/71 an East to West or West to East transect with photos being taken every 9 paces. The unit was angled in such a way that the shadow from the pole and camera was not included in the photo. In the larger plots at the Uthe farm and the Poets facility, 30 to 40 paces were taken between each photo. The self timer on the camera was set for a 10 second delay and the camera was focused before initiating the timer. In most instances, 10 seconds was ample time to maneuver the camera into position for the photo. The cameras motion stabilizer function was turned on and the18mm zoom setting was always used to capture the maximum amount of area in each photo. Cold days, and wind speeds in excess of 30mph present a challenge. Photos were downloaded from the camera with the EOS utility software supplied with the camera and analyzed with sample point version 1.51 with a grid size of 10x10 chosen. A newer version of sample point is available at http://www.samplepoint.org/.