In farming, little things can add up to make a big difference. This is certainly the case when it comes to balanced crop nutrition.
That’s why we need to have an understanding not only of the vital role played by each of the 17 essential plant nutrients , but also how those nutrients find their way into the plant to play that essential role.
While we see uptake in the Big Three macronutrients — nitrogen (N), phosphorus (P) and potassium (K) — measured in pounds per acre, the micronutrients are taken up and measured in ounces per acre.
Although taken up in small amounts, micronutrients play a crucial role in crop development. It should also be noted that, as you look at the growth cycle of a plant, research suggests that periods of peak micronutrient uptake are often narrower than for macronutrients.
Beyond CropNutrition.com, there are many great resources available online to help retailers and growers better understand micronutrients. As an example, George Rehm with the University of Minnesota published a paper titled “The Mighty Micronutrients”, which offers an insightful review of seven of the eight micronutrients.
In the past several years, we’ve learned a great deal about micronutrients and the role they play in crop nutrition, but as an industry, we still have plenty of work to do in terms of sharing that information with farmers, whose yields could certainly benefit from this information.
Take zinc (Zn), for example.
Zinc’s primary role is an important one — activating enzymes within the plant that speed chemical reactions, some of which create growth and spur development of the plant. Yet Zn deficiency is the most common micronutrient deficiency in the world.
We also understand the availability of zinc in soils is directly related to soil pH; that is, higher pH levels limit zinc availability. In addition to high pH and/or low soil test Zn, crops in early growth stages or enduring cool, wet and cloudy weather may express Zn deficiency. Soils with high soil test phosphorus may also show signs of Zn deficiency and lack balanced crop nutrition.
As we continue to progress into higher-yielding systems and deplete the soil of micronutrients, it’s important to think small with regard to crop nutrition. Understanding each essential micronutrient, how it is used within the crop, and the signs of deficiency are each essential steps in formulating a balanced crop nutrition plan.
Curt Woolfolk is a Product Development Specialist for The Mosaic Company. He leads the on-farm research and development program in North America, which includes testing Mosaic premium products, as well as new product concepts in pre-commercial stages.