Over- or under-fertilizing negatively impacts yield, so farmers need to know the needs of their soil.
Above is a 60-acre field that was sampled in one-acre grids. The numbers listed represent the amount of phosphorus in parts per million in each grid. Note the variance from nine on the low side to 91 on the high side.
What farmers are now able to do is create what we call “controller files” based off maps like these, and then apply different rates of fertilizer as they cross the field. What this allows farmers to do is better invest their fertilizer dollars. Instead of spreading the same rate across the entire field, this type of precise application means all areas of the farm can have a good chance of producing high yield. Plus, it is a great thing for the environment. Instead of having excess fertility in certain areas, those spots are effectively “mined” down to normal levels.
Students can learn more about soil sampling and fertilizer application with our Soil and sustainability lessons.
credit: Vital by POET newsletter, Winter 2019