Written by: Mr. Peter KlapwijkGreen Architect and Connector with a vast growing history.

Just like humans, plants need an optimal nutrient balance to thrive. Crops that receive the right amount of nutrients have higher yields and better fruit. To obtain these results, farmers need precise irrigation and fertilization strategies.

What is an optimal nutrient balance?

Continuing with the human metaphor, an optimal nutrient balance depends on the age and situation of the subject. For example, children and adults have different needs, as do men and women. A person’s lifestyle and environment also influence their optimal nutrient balance.

Similarly, crops each have their own needs. Their needs may be influenced by:

  • The age and stage of the crop
  • Whether the crop is producing fruits
  • The season and climate
  • The weather and environment
  • The soil and growth medium

Even understanding these factors, each plant may have different needs. Two plants of the same species in the same environment might have needs that vary by up to 30%. It’s not unusual for plants to require 20% more nutrients than average, while other plants might need 10% less than average.

To ensure crops receive the nutrients they need, farmers may be tempted to overfertilize and offer excess nutrients, thinking that the excess will just wash away through the drain water. Not only is this wasteful, leading to excess costs and wasted fertilizer, but it can also be harmful to plants. In fact, if the nutrient concentration or electrical conductivity (EC) in your nutrient solution is too high, plants might transpire less and lower transpiration can hinder growth. Roots tend to absorb water with lower EC faster.

Additionally, an excess of any one specific nutrient can also be harmful. For example, too much potassium might limit growth. Farmers must find the right balance between offering enough nutrients without overfeeding crops.

What nutrients do plants need?

There are multiple nutrients plants need to grow optimally.

  • Nitrogen–Nitrogen is one of the top elements for plant growth. This element is a key ingredient in all plant cells and is necessary for the photosynthesis process. Nitrogen might be considered the gasoline that fuels the plant’s engine.
  • Calcium—Calcium helps build the walls of plant cells in the stem, roots, and leaves. It is important for a strong structure and a bright green color.
  • Potassium—Potassium is important for the vascular structure of the plant. It ensures necessary starches, sugars, and oils are dispersed through the plant, leading to increased vigor, disease resistance, and fruit quality.
  • Sodium—Sodium is not generally considered a necessary nutrient for plants, but it can help improve a plant’s metabolism. Farmers however need to be careful not to give plants too much sodium, as this can interfere with the plant’s ability to absorb other nutrients.

Using irrigation to obtain nutrient balance

Your irrigation strategy should be based on the needs of your crops, including their nutritional needs. In this article, we are discussing irrigation strategy when growing on substrates.

An irrigation strategy is built of two components: nutrients and water. You can provide nutrients through fertilizers that include a mix of nutrients, or you can add single nutrients to your growing medium. Whichever you choose should be based on what your plants need and what is available from local suppliers.

Water is the second element of your irrigation strategy and can be used to ensure your plants receive the right amount of nutrients. To start, consider how much water plants generally need in a day. To ensure your plants never get over-dry, you might choose to increase this amount by 25%. For example, if a plant needs one liter per day, you might provide 1.25 liters.

It’s important not to overwater your plants. Too much water will eliminate the oxygen in a substrate. Oxygen is important for root growth and helps plants absorb nutrients. You want to provide water only when the previous shot of water is almost depleted.

One irrigation strategy that helps farmers avoid overwatering is by providing large shots of water for longer time periods less often. This ensures that your substrates are saturated and allows plants to continuously absorb the water until it is almost depleted before you provide another shot of water.

Every time you give water, you are flushing elements in the soil. This is another reason to water less often if you are providing specific amounts of nutrients to your plants. If you give too much of one element, you can increase the water content to flush the element and equalize the soil.

Using irrigation to obtain nutrient balance

Using irrigation to avoid disease

Your irrigation strategy should also include the timing of water shots to avoid diseases. There are many plant diseases that start from fungi and bacteria found in free water. You don’t want this free water to be soaking into the substrate and become a breeding ground for fungi and mildew to germinate.

Water shots should always be given while plants are transpiring. Plants transpire the most during the day, so much of your irrigation should take place during the daylight. Any water shots given too early in the morning or too late in the evening can lead to disease.

Monitoring and improving your irrigation strategy

If you want optimal growth, you will need to anticipate crops’ needs and provide exact amounts of nutrients and water. To do this, you will need to test your irrigation strategy and nutrient concentrations and measure the results. Here are a few things that you should check:

  • Dripper input and output—Are your drippers operating consistently? It’s important to check that all drippers provide an equal amount of water.
  • Wet scale—Use electronic measurement equipment to check the water content of your substrates. This will tell you whether you are providing the right amount of water.
  • Drain water—Analyzing the drain water will tell you how much nutrients the plants are absorbing. If there are a lot of excess nutrients, you might be giving too much. Drain water can also be recirculated after disinfection so the excess nutrients are not wasted.
  • Plant samples—You can examine crop samples in a laboratory to see how they react to different nutrients.

Once you know what your plants need, you’ll be equipped to proactively anticipate how to care best for your crops. Your plants will thank you will higher quality fruit, increased yield, and a bigger bottom line.


Mr. Peter Klapwijk is currently delving into R&D. In the past, his work was very practical, and he helped so many companies. He thoroughly enjoys working with Paskal and all their latest innovative developments while always trying to keep it simple.

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