Optimum strategies for mapping management zones using temporal remote sensing information

Non-Peer ReviewedTechnological advances in variable rate application and global positioning systems (GPS) make site-specific management technically feasible. No longer do fertilizer and pesticides need to be applied uniformly across a field, they may be varied to match the soil productivity across the field. However, successful site-specific management depends on identifying management zones and the determining optimum input application rate for those zones Unfortunately, identifying management zones that are reasonably consistent from year to year has been the greatest problem to successful site-specific management. In this study we found that crop vigor measured with normalized difference vegetation index (NDVI) based on satellite (LANDSAT) remote sensing for two different years was successful for identifying management zones. Based on the NDVI, we divided a field near Shaunavon in southwestern Saskatchewan into two zones: zone 1 with low crop and vigor zone 2 with high crop vigor. The zones corresponded to differences in soils, particularly, soil moisture, but it would be too costly and impractical to try to delineate these zones from detailed soil sampling. Wheat yield and protein were more responsive to N in zone 1 than in zone 2. The optimal N fertilizer rate was 95 kg/ha for zone 1 and 75 kg/ha for zone 2. Satellite remote sensing is a cost-effective method to delineate management zones for site-specific management