Weed mapping uses NDVI imaging from tools like Greenseeker or satellites to identify high density weed areas within paddocks. This allows farmers to target treatment of problem areas in isolation rather than blanketing entire fields. Weed pressure is uneven across fields, so prescription spraying only the worst spots leads to savings on chemicals and more robust weed control compared to uniform treatment of entire paddocks. On a 222 hectare property, weed mapping identified 31 hectares of high pressure areas, allowing treatment of just those spots and saving over $4,700 compared to blanket spraying the whole field.