Dave works with family running a 900-acre farm near the Mississippi river in central Minnesota. “We grow corn and soybeans, but our real cash crop is Russet potatoes,” said Dave. Their potatoes grow well in the sandy soils by the river. And their reputation for quality helps secure ongoing contracts with local grocery stores.
“While the sandy soils are good for potato growth, water and nutrients can pass through pretty quickly,” said Dave, “so we rely on the moisture sensors to keep the fertigation levels right.” With over application, nutrients wash through the root zone and are wasted. With under application, potatoes don’t reach the size to earn a baking potato premium price.
“We like to supply the local market as much as possible. We grow some reds and yellow potatoes, but about 80 percent of our acreage is devoted to russets. Luckily, we earned a contract to supply Walmart’s Minnesota stores and that can move a lot of volume. We also sell to stores like Corburns, so we want the size and quality of our potatoes to be consistent.
Irrigation and fertigation are the main factors that lead to maximizing potato growth and consistency. While Dave has been using tensiometer sensors to help determine soil moisture levels, he’s now comparing them against the EarthScout units to see what he prefers. “I put the EarthScout units about five feet away from my tensiometers so I can compare and see what I like best. The tensiometers work pretty well, but they’re a hassle to move around and re-install. I have to use a separate device to measure soil temperature and use a rain gage bucket, too. With the EarthScout, install was super easy, and I can mix and match sensors to configure it how I need,” explains Dave.
Dave also likes that he can switch sensors as needed to get the most out of his growing season. “After the spring, we don’t care as much about soil temperature, and would rather focus on wind speed and solar radiation to figure out our irrigation needs.” he explains.
Next season, Dave plans to use several EarthScout units with configurations that measure moisture, soil temperature, windspeed and solar radiation. “That way we can really dial-in on our irrigation needs. We can have some units that focus on what’s going on in the ground, plus one set up as a local weather station to get a better read on our micro-climate. And once we get the alarms set up on my phone app, that will make it super easy to stay on top of things.”