Below is an example of a map that I set up to illustrate a how we use management zones in our farming operation. The three colors each indicate a management zone. Red signifies a C management zone, areas of the field that don’t yield as well. Yellow indicates a B management zone, or areas that are average for the field, and Green indicates an A management zone, areas of the field that are high yielding. Everything we do is based upon management zones that we set up for every field. Not every field will have 3 management zones, some only have 2 because yield is consistent over the entire field. The management zones drive all of our decisions for planting population, fertility, pest management, basically how intensely we manage area of the field.
The red areas of the field will be planted at a lower seed population, as much as 4,000-6,000 seeds per acre lower than the yellow areas of the field, because we know those areas will not yield as well. In addition, we will apply lower rates of phosphorous, potassium and nitrogen, because a lower yielding crop requires less fertilizer. Because these areas are referenced by GPS, we can choose to treat problems during the growing season differently depending on the area of the field.
The yellow areas of the field are planted approximately 2,000-3,000 seeds per acre lower than the tan areas of the field. Phosphorous, potassium and nitrogen rates are higher than the red areas, but lower than the yellow areas.
The green areas of the field get the highest amounts of inputs. The planted populations are pushed to the highest recommendations for the variety we are planting in that field. Fertilizer rates are increased in these areas too, because a high yielding crop requires more fertilizer. However, we don’t apply more fertilizer than what is required for the yield goal for that area of the field, based on information from Universities and from our own studies. Our typical nitrogen rates for corn are around .9 pounds of nitrogen per bushel of corn, which is lower that what Universities recommend. In this field, the yield goal for the red areas might be 190 bushels of corn per acre, 220 bushels per acre in the yellow areas and 250 bushels per acre in the green areas.
We also utilize a farming practice called strip-till, where we use an implement in the fall to inject phosphorous, potassium and nitrogen in the ground while tilling a strip of ground 8 inches wide. This allows us to cut our phosphorous and potassium rates by 20% because they are in a higher concentration in the strip and are more available to be used by the plant the following year. Also, because we inject the fertilizer in the ground, there is no risk of fertilizer run-off to contaminate watersheds.
So, that’s how we utilize management zones and strip-till in our farming operation. Not only does it benefit us on the bottom line, but we feel it is a benefit to the environment as well. It allows us to accurately place fertilizer where it is needed, at lower rates, underground where it is safe. And since we aren’t doing any tillage, soil erosion is much less of a problem as well. Let me know what you think, I welcome any questions you may have!