Humic Acid: The Kickstart that your Crops need?

Humic Acid: The Kickstart that your Crops need?

Humic acid is the primary active ingredient that is the starting point of a healthy, microbially active soil. A good soil is continuously releasing humic acid (or humins), depending on rain, water, soil temperature and other conditions. 

High humic acid levels can increase crop yields. On the other hand, humic acid deficiency can prevent farmers and gardeners from growing crops with optimum nutrition. Thus, adding humic acid inputs to favour the biology of the soil and chemistry can produce better yields and quality. 

The multiple functions associated with humic acid make this high-quality, soluble granule a priority raw material in every sustainable farming practice.

What is humic acid?

Humic acid is a remarkable brown to black product of soil chemistry that is essential for healthy and productive soils. Humic acid comprises a group of molecules that are soluble in water only at higher soil pH values. The molecules bind to plant roots and help plants absord water and nutrients. One of the most functional components of humic acid is the water-extractable organic carbon (WEOC), which is an important food source for many beneficial soil microbes, especially fungi. 

What is the difference between organic matter and humus?

  • Humus = a general term that describes a group of separate but distinct humic substances.
  • Organic matter = material that is decomposing at various rates in the ground.
  • Humic acid = a humic substance.

What are the benefits of high humic acid levels? 

Humic acids are extremely important as a medium for transporting nutrients from the soil to the plant because they can hold onto ionised nutrients, preventing them from leaching away. Humic acids are also attracted to the depletion zone of the plant root. When they arrive at the roots, they bring along water and nutrients that the plant needs. The functionalised humic acid molecules act as photosensitisers, retain water, bind to clay, act as plant growth stimulants, and scavenge toxic pollutants. 

Humic acid also promotes the return of beneficial fungi which are missing in many soils, creating a crumb structure which increases the permeability of the soil and thus increases nutrient, water and oxygen uptake and retention. It is microbe-friendly, improves nitrogen efficiency, reduces phosphate lock-up, and is an excellent source of water-soluble carbon, essential to the creation of healthy soils.

Healthy soil (and thus healthy plants) are dependent on adequate humus levels. 


humic acid
An example of a soil with good crumb structure, root formation, and organic matter, which would, therefore, have high levels of humic acid.

Summary of the benefits of humic acid 

  • Soil with high humic acid levels can become more porous with better drainage, resulting in deeper root growth of all plants.
  • Retains water and the ionised nutrients that are produced by the natural cycling of compost, organic biomass, or other sources of fertiliser.
  • Promotes soil structure improvement by promoting fungi to create a crumb structure for better water and oxygen intake, and improved root penetration.
  • Stabilises nitrogen and improves nitrogen efficiency (ideal as an additive with urea).
  • Complexes phosphate to reduce lock-ups (ideal as an additive with DAP/MAP, etc.).
  • Natural chelating and complexing agent to help magnify nutrient absorption.
  • Increases the permeability of cells to increase nutrient uptake by up to 40%.
  • Contains an auxin-like growth promotant that can enhance cell division and elongation.
  • Can buffer the effects of excessive elements (particularly sodium), toxic chemicals and heavy metals.
  • PH buffering capacity to help neutralise the problems associated with pH extremes.
  • Features a CEC of 450, which aids in moisture and nutrient retention.
  • Promotes better seed germination in a shorter time.
  • Microbe-friendly.

How to apply humic acid 

Ideally, humic acid should be added as an input in small amounts (i.e. 1kg/ha monthly), rather than dumping a large amount in one go. A weekly trickle feed (or even a daily feed, if practically possible) is especially beneficial for very sandy soils that don’t have much organic matter to act as a back-up release of humic acid.

Humic acids are a key ingredient in developing and maintaining healthy and sustainable soil

At Zylem, we use NTS Soluble Humate Granules™ to improve soil structure and magnify nutrient uptake. Derived from leonardite (brown coal), NTS Soluble Humate Granules™ contain a minimum of 70% potassium humate and act as an additive to granular fertilisers such as urea. Being highly soluble, NTS Soluble Humate Granules™ dissolve easily for application via irrigation systems. 

NTS Soluble Humate Granules™ work by promoting the creation of beneficial fungi – which are missing in many soils. These fungi create a crumb structure, optimising soil structure for better water and oxygen uptake and improved root penetration. The effect is better seed germination in a shorter time and improvement in overall crop yield.

The team at Zylem are on hand to explain applications and precautions associated with humic acid. Get in touch to find out more.

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