Ashburn, GA, (very close to Heaven!) | Will this work? YES, if, and only if, your field production variability follows "soil type" variability. If your fertilizer company is using your county soil maps to set up management zones, that is a very good start.
However, remember, there are limitations to the accuracies of soil maps. "Many were drawn from the basement of the courthouse" is what I heard a leading Illinois soil consultant say once in a consultant meeting.
Okay, assume your soil maps are accurate at the time they were drawn. Here and now in 2008, your field has probably been farmed and farmed and farmed for three or four decades. You may have taken woods, hedge rows, and pastures since then. You may have installed drain tile, built terraces, took down terraces, taken out old field roads, or built waterways.
Next, assume that the CURRENT soil maps REMAIN pretty accurate. Will your nutrient variability follow a parallel to the soil type changes? As you saw in the post by "soil-life", there are lots of ways to look for variability. Running a Veris rig and getting EC ratings is good. Do you run a yield montitor and log yield data? Do you look at current imagery of your field with NRCS maps, MrSids, or even Google Earth? Incorporating a systems approach to identifying management zones is a very good way to go. It is more intense, but significantly more effective than "spreading by soil types at no extra expense."
"Spreading by soil types at no extra expense" is an interesting advertisement in itself. Do they mean lime, P, K, N, as well as minor elements? What if nematodes are your limiting factor in those marginal zones? Their spreading by zones will not solve that! You could have wet bottoms in wet years that won't produce, while the sand ridges do well then!
"Soil-life" hit on something else, in that many times the marginal yield areas of the field are higher in fertility!
In this economic environment, it is very critical to implement an intense, systems approach. |
Spread fertilizer by soil types?
