In-season tissue sampling helps inform farmers and retailers about nutrient deficiencies. Winfield United analyzed more than 25,000 tissue samples in 2017 and compared the results with samples taken in 2016.
Across the U.S., the company saw increased deficiencies in nitrogen, potassium, sulfur, zinc, manganese and boron in corn. For instance, nearly 82% of sampled corn plants were short on zinc.
In soybeans, the results showed an increased deficiency in copper, potassium and manganese. Sixty-five percent of the soybeans sampled were lacking in copper.
However, nutrient deficiencies can and do differ by location. For example, Andrew Lambert, a crop adviser for Centra Sota cooperative based in Minnesota, says in his area nearly 90% of all corn samples came back deficient in zinc.
Lambert’s solution was to have farmers apply zinc in-furrow. With one farmer, he tracked out the weight-to-yield and return on bushels in the hopper to the specific product and found it was successful.
“The product came back responsive at some points, so now we plan on upping the amount to see if we get additional ROI,” Lambert says.
In soybean samples, Lambert says nearly 99% were deficient in copper. Many of the samples were also low in potassium and phosphorus.
Lambert believes much of the copper deficiency was due to the time the sample was taken, which was during a rapid growth stage when plants are naturally deficient in nutrients. To address this, he says farmers can spray foliar products.
Lambert emphasizes in-season tissue sampling is the best way for a farmer to tell if corrective treatments will payoff. “Anything a farmer can know more about his situation to make him more efficient helps.”