Understanding each field’s soil is key to maximizing yield potential.
That’s the philosophy Fieldwalker Agronomy’s Jonathan Zettler takes to the field when advising clients on how to best manage the unique environments throughout their farms.
On this episode of the RealAgriculture Soil School, host Bernard Tobin catches up with Zettler at Luymes Farms at Moorefield, Ont., where the agronomist has been using soil, water and topography maps — more commonly know as SWAT Maps — to manage fields for five years.
In the video, Zettler looks at one of the first SWAT-mapped field in Ontario and shares how he and Luymes Farms have worked together to use variable rate seeding and nitrogen application to optimize yield and return on crop input dollars.
Zettler notes that understanding the landscape of the field is one key to success. Identifying nitrate levels in knolls, mid-slopes and depressions is critical for applying the right nitrogen levels to unlock yield potential across the field. This year, nitrate testing showed the knolls at 25 ppm, mid-slopes at 40 ppm and depressions in the 70 ppm range.
Depressions tend to have higher nitrate rates, but based on field history and weather conditions, Zettler notes that depressions sometimes flood so yield can vary based on the seasonal environment. Based on these factors, nitrogen is not a limiting factor so lower rates are applied.
The knolls have strong yield potential and are very nitrogen responsive, so rates tend to get cranked up in these areas. Zettler refers to the mid-slopes as the “Goldilocks” zones of the field; here, the crop typically sees the best growing environment with the best rooting potential, and commands the highest nitrogen rate and strongest seeding rate.
When growers tie soil, water, typography and inputs together, Zettler says there is a strong return on that management investment. He estimates the strategy has added 30 bu/ac of corn to this field at Luymes Farms. (See video below.)
Tap here for more Soil School videos.