Opinion: The Nuances of Crop Nutrition

There are some persistent misunderstandings when it comes to plant nutrition that hinder the development of maximizing the utility of this most central agri-input. It is very important to understand what nutrition actually accomplishes. But it is equally important to understand what nutrition is not doing.

Fertilizers cannot, in and of themselves, achieve anything in the crop.


Every process and structure that is generated by the crop is due to the amazing mechanics, structure, and program code (DNA) within each plant. Nothing else can achieve growth, fruiting, and yield.

However, these mechanics are in demand of resources to fulfill their functions. And that is where nutrients enter the picture.
To a large degree the misunderstandings derive from the fact that nutrients often are coupled with properties in the plant, which by the way, is correct to a large degree.

However, the problem with this approach is that it is easy to miss the most elementary function of plant nutrients — that they are building blocks in the plants. If this isn’t clear, all communication on plant nutrition will be misunderstood.

The most central building blocks in plants are the carbon compounds obtained from the atmospheric CO2 through photosynthesis. The nutrients, in contrast, are specialized building blocks with properties that enable the different functions in the plant.

The analogy of building a house is useful here. The carbon can be likened to bricks, while the nutrients can be likened to special components, such as pillars, roof beams, and mortar, etc.

Furthermore, it is not so relevant from a fertilizer manufacturer’s, distributor’s or even a grower’s perspective exactly what function an individual nutrient fulfills. It is more about the net effects on yield and quality and what consequences there might be in case of a deficient supply of fertilizers.

That is why I find it odd when fertilizer distributors market their products based on what this or that nutrient will accomplish, as if the crop then suddenly will be able to perform something entirely different due to the input of a single plant nutrient.

The crops always need all essential nutrients. The purpose of the input is to ensure that the crop has everything it needs in a state of balance between all needed resources.

The following is an example of a classical misunderstanding — that nitrogen is considered to favor growth. It’s not hard to understand where the idea comes from, as nitrogen application often results in increased growth. However, nitrogen has no mysterious property that can promote growth.

No, the question is whether the demand for nitrogen is saturated or not. If not, additional supply can be used for growth. But if the demand is saturated, it doesn’t matter how much is added; it cannot increase growth. This is true for all nutrients. It does not only apply to nitrogen.

Now, we need to clarify one thing: It does not follow from the above rationale that we cannot affect or manipulate the performance of the crop. We can! And actually even more so than what was generally understood.

The principle of demand and saturation of a nutrient regulates not only growth but all processes in the plant. Therefore, nutrition is about supplying according to the demand of the crop.

But it’s also about tweaking the balance of all the resources made available to the crop in the direction of the production goal. It is important to understand that we are working with a trade-off mechanism; when we favor a specific trait, it will be at the expense of another.

Manufacturers and distributors should point to the value of providing high-quality fertilizers that enable great nutrient status in the crops and the benefits of products that can either meet the need for specific nutrients or tilt the balance to favor the sought-after results.

If distributors educate growers in these benefits, and knowledge spreading can serve as the basis for marketing, fertilizer expertise becomes a very powerful tool for promoting plant nutrient products. Real knowledge that is empirically verified not only creates trust but also delivers value to the customer from the first interaction, which is the foundation of all good long-term business relations.

So, even though I have made it clear that we can’t have an over-reliance on what an individual nutrient can accomplish, what I have shared is really good news, as it can serve as a basis for setting the right expectations. Such expectations are not only more accurate than those based on what a certain nutrient will do in the crop; they are actually more likely to create a higher ROI as they pave the way for a more correct and precise use.