It has been the contention of many agronomists, including Ken Ferrie, well known agronomist at the Farm Journal, that seed placement for corn is critical. In fact, double digit yield losses in corn from improper planting are unfortunately common. Thankfully, rapid advances in plant technology and seed monitoring have greatly enhanced seeding accuracy.
Today’s planters also can precisely vary seed rate according to a predetermined map. How the map is made depends on the quality of the outcome. Yields vary because of weeds, insects, disease, compaction, poor drainage, over and/or under irrigation, soil changes, etc… Making a variable rate seed map from only a yield map stands a significant chance of inaccurately reflecting the true productivity potential of the field. The most important base layer for variable rate seeding is an accurate soils map.
Additional layers would include a yield map, nutrient maps including ASNT, an organic matter map, etc… Since all water moves down slope, a topographical map is very beneficial in irrigation agriculture. In the end, the map is only as good as the data used to make the variable rate seeding map. Many seed and fertilizer companies have the capacity to make the maps in house. There are several companies who provide this service commercially. MISS customers can have this service directly through MISS.