Although boron (B) is considered the most deficient micronutrient in the world after zinc, dynamics of B use in plants and soils have continued to perplex farmers, agronomists and researchers for decades.
The objective of a recently published study conducted by University of Illinois plant physiologist Dr. Fred Below and recent doctoral graduates Dr. Ross Bender and Dr. Jason Haegele was to identify which secondary macronutrients and micronutrients demand attention in a new era of soybean production.
Even with the increased focus on micronutrients and their importance to crop health and yields, basing a solid nutrient management plan on macronutrients is still critical. While macronutrients and micronutrients certainly work best together to create a balanced approach to crop nutrition, the key difference between them is the amount needed for proper plant growth.
Boron is a micronutrient critical to the growth and health of all crops. It is a component of plant cell walls and reproductive structures. Boron can be found in soil solution, adsorbed to soil surfaces, organic matter, and is part of soil mineralogy. Boron is a mobile nutrient, meaning that it is prone to movement within the soil.
One of the micronutrients that is essential for crop health also happens to be one of the most deficient in the majority of fields: boron.
Raising a productive crop depends greatly on the nutrients a plant is able to access during its life cycle. Many factors influence the availability of those nutrients, including soil pH. For instance, as soil pH increases, the availability of phosphorus (P), zinc (Zn) and iron (Fe) decreases. Although variety selection can help manage iron deficiency in soybeans, fertilizer application is still needed to address the P and Zn deficiencies prevalent in high-pH soils.
In farming, little things can add up to make a big difference. This is certainly the case when it comes to balanced crop nutrition.
As yield levels increase, so does the demand for nutrients not often considered as standard practice. This means that a high-yield system requires more attention be paid to micronutrients. In fact, is it possible that we are pushing the limits of our soil as we push yields to the next level.
Rapid adoption of rootworm-resistant corn hybrids in the past five years has helped many farmers take corn yields to the next level. While corn varieties with insect resistance traits have eased insect control, it's important to remember that the investment in high-tech seed must be paired with other state-of-the-art agronomic practices, including a strong soil fertility program and balanced crop nutrition.
"As much as 60 percent of yield depends on soil fertility," says Curt Woolfolk, Manager of Crop Nutrition Technologies for The Mosaic Company. "Regardless of what we spend on crop inputs, if we haven't taken care of our base soil fertility, we're not going to maximize the yield potential of the crop."
Justus von Liebig, a 19th century German chemist, made great contributions to the science of plant nutrition and soil fertility. While Carl Sprengel, a German botanist, formulated the “theory of minimum,” Liebig investigated and popularized the scientific concept we know today as “Liebig’s Law of the Minimum.” This concept demonstrates that plant growth is not controlled by the total amount of available resources but by the scarcest.
High seed prices, volatile commodity markets, unpredictable weather: It’s a long list of big concerns that keeps farmers up at night. It’s those concerns that make the details that drive return on investment of paramount importance. Details like micronutrients.