AGRICULTURE RESEARCH AND EDUCATION CENTER
Welcome to the Agriculture Research Center—we are a collective group of scientific organizations. Our nationally-coordinated teams address the difficulties that affect agriculture around the world.
Through grants and federal funding we are able to promote solutions that help growers to overcome today’s agriculture challenges.
Micronutrients…..are they the Key?
There are 17 essential nutrients for healthy plant growth. Of these, eight nutrients are required in smaller amounts (boron, chlorine, copper, iron, manganese, molybdenum, nickel and zinc), dubbed micro-nutrients. Several elements that have been identified as non-essential, yet beneficial such as cobalt, silicon, selenium, vanadium, etc.
Micronutrients can sometimes be treated as an afterthought. However, in many ways micro-nutrients hold the key to how well the other nutrients are used and how well the plant grows, develops and yields.
Micronutrients are known to play many benefits in plant development and health. Micro-nutrients promote the strong, steady growth of crops that produce higher yields and increase harvest quality, maximizing a plant’s genetic potential. Their presence can have a great impact on root development, fruit setting and grain filling, seed viability and plant vigor.
Micro-nutrient deficiency can result in stunted growth, low yields, die back and even plant death. They also benefit plants indirectly by feeding the microorganisms in the soil that perform important steps in various nutrient cycles of the soil-plant root system.
Relationship With Soil
Micro-nutrients occur naturally in soil minerals, which gradually break down from rock minerals and release in forms that are available to plants. A critically important concept is that of their availability to plants. Micro-nutrients can sometimes be present in soils but not in a chemical form that roots are able to absorb. Soil physical characteristics and environmental conditions play key roles in determining when and how available soil nutrients, especially micro-nutrients.
For example, acid leaching can remove micro-nutrients from the soil, as can intensive cropping. Also, excessive use of phosphate fertilizers can diminish the availability of some micro-nutrients, particularly iron and zinc.
In other cases, extremes in soil pH can result in reduced micro-nutrient availability or even cause micro-nutrient toxicity. Most plants have a pH range “sweet spot” in which the micro-nutrients in the soil are soluble enough to satisfy plant needs without becoming so soluble as to become toxic.
The soil itself matters as well. Soils very low or very high in organic matter or with sandy texture or heavy clay can result in micro-nutrient imbalance. Soil erosion can carry away humus and organic matter in which some micro-nutrients are held. Cold, wet soils can result in slowing or stopping plant root development.
Once the need for a micro-nutrient supplement has been determined, the next steps are clearly identified by the industry standards set out in the 4R’s of Nutrient Stewardship. These include determining the Right Source for supplying the target nutrient, applying the Right Rate for optimal benefit, at the Right Time of application during day, growth stage or the growing season. A detailed discussion of those three Rs is beyond the scope of this article. However, we will further expound upon the fourth R, Right Place, which addresses the application placement and method.
It makes sense to have a comprehensive micro-nutrient plan in place to ensure that you are getting the best crop yields for your money and the extra effort invested. Remember, if you allow micro-nutrient deficiencies to become a limiting factor in crop development, further application of water, macronutrient fertilizers and other resources/time may give a limited return or be wasted.
Planning begins by knowing which of your fields and which of your crops are most susceptible to micro-nutrient deficiencies. When problems are identified and successfully treated, you must keep good records of what was done for future reference. It is also essential to continuously monitor your fields for possible future micro-nutrient problems. Be aware of any special physical or environmental conditions that may affect future micro-nutrient availability to your crop.
Micro-nutrient needs vary with the type of soil, crop planted, available nutrient source and whether or not the crop is irrigated or dry land. Review resources that apply to your locale and discuss your test analyses with your county extension office or your agriculture retailer. It is important to find the best micro-nutrient solutions, including the correct amounts and application timing to help you reach a complete and healthy balance of all the essential nutrients resulting in more production.