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Plants require a total of 16 nutrients to grow, develop, reproduce and remain healthy. Three of these nutrients – nitrogen (N), phosphorus (P) and potassium (K) – are required in relatively large amounts. These are known as macronutrients.

Existing in a delicate balance with each other, the macronutrients each have a big role to play in the health of a crop.

  • Nitrogen, necessary for the formation of amino acids, proteins, DNA and RNA, is essential for plant cell division and vital for plant growth.
  • Phosphorus is critical in the promotion of early root formation and growth, and is involved in photosynthesis, respiration, energy storage and transfer, cell division and enlargement.
  • Potassium is involved in carbohydrate metabolism and the break down and translocation of starch. Potassium also enhances disease resistance and improves winter hardiness.

Nutrient Interactions

For a healthy crop and abundant yield, it is very important to ensure a healthy balance of all three macronutrients. Because, as we learned in the first blog post of this series, too much of one nutrient can cause a decrease in the uptake of another.

For example, high levels of nitrogen can cause a potassium deficiency. Applying nitrogen to increase yield requires more plant-available potassium in the soil; without the sufficient amount of potassium, the response to nitrogen application will be limited. And, high levels of phosphorus can reduce the availability of potassium, resulting in a deficiency in the crop.

Macronutrients can also antagonize the uptake of micronutrients, such as boron. High levels of nitrogen can assist boron but in excess can dilute it, while low soil levels of nitrogen can reduce boron uptake.

Here are other examples of interactions and antagonisms between the macro- and micronutrients:

Over application of: Induced deficiency:
Nitrogen Copper
Phosphorus Copper
Phosphorus Iron
Phosphorus Zinc
Phosphorus Boron
Potassium Boron
Potassium Magnesium
Potassium Iron

Balancing nutrients to grow a good crop can be a challenging task, but your OMEX representative can help. Contact your rep today to find out more about the Primers, Starters and Foliars that can help you meet your yield goals.

In our next post in this series, we will discuss the interactions between the secondary nutrients: magnesium, calcium and sulfur.