Maize yield versus soil phosphorus. To compare the yield with the P fertilization within the VR treatment plots a lab VIEW program was developed to match the corresponding cells of soil P detected by the soil sensor during the maize planting with the nearest yield data points. The DGPS coordinates recorded on both implements was used to match the position of the Pal and corresponding yield within a field spot. From each treatment about 35 samples were randomly selected and the analysis of variance was performed to compare the yield of both treatments, VR and UR.