Robert Mullen Soil Quotations

One reason is that the system assumes the soil is a blank medium and devoid of natural nitrogen. We know that's not true. And the problem we run into is that we don't know exactly how much nitrogen is in the soil and how much will be available to the crop. The release of nitrogen is dependent on the weather, so there's always a possibility of adding more or less nitrogen to the soil than is needed.

Optical sensors are an indirect assessment of soil fertility because it is using plants to give an indication of how well that soil is supporting the crop. There is also a wildcard in this technology with making recommendations and improving efficiency. And that's if there will be federal dollars available for growers to adopt it.

Current nitrogen recommendations assume four things: yield potential doesn't vary year after year, the yield level the soil will support without supplemental nitrogen is negligible, pre-plant nitrogen will be available throughout the growing season, and soil uniformity produces similar yield results across the field. Growers know that none of these assumptions are entirely accurate, and they can potentially be avoided using optical sensors.