Berkshire, England: Humic acid has many functions in the soil, both chemical and physical. Chemically it aids in the breakdown of toxins and directly reduces the uptake of toxins in plants. It also directly encourages microbial growth of both flora and fauna, which add to general soil fertility and health.

Humic acid has also been found to assist in seed germination and plant growth as well as improving resistance to fungal attack.

Humic acids cannot be used as a fix for turf under stress, but can be used to help prevent it.

“Regular applications of humic acid are the only way to ensure you reduce the risk of stress to the turf to the lowest level,” said Brian Croose, Asean Regional Manager for Indigrow, a Full Business Member of the Asian Golf Industry Federation. 

Cation Exchange Capacity

The Cation Exchange Capacity (CEC) indicates the soil’s capacity to hold cations (Calcium, Magnesium, Potassium, Sodium).

The two main colloidal particles in the soil are clay and humus. The CEC of the soil is determined by the amount of clay and/or humus.

These two colloidal substances act as the cation ‘warehouse’ of the soil. Sandy soils with very little organic matter will have a very low CEC while heavy clay soils with high levels of organic matter will have a much greater capacity to hold cations.

Humic Acid

Humic acid can also help to increase the Cation Exchange Capacity of the soil. A high CEC helps the soil to cling on to the nutrients, keeping them available to the turf. This is particularly important in climates where regular watering is required.

Croose said: “Our fertilisers based on humic acid are produced to have fully homogenous granules, ensuring the accurate spread of nutrients. They contain high levels of organic matter to help improve all round soil health, with particularly strong effects on sand-based rootzones.

“They release nutrients bound within the rhizosphere, making them available and more accessible for uptake and can induce a ‘nutrient acquisition response’ which can enhance the production of phyto-hormones.”

The high organic matter content provides fuel for microbes and general soil biota along with several forms of nitrogen to provide balanced, steady release of nitrogen for strong healthy growth.

Humik N25 Trials

Humik N25 is a nitrogen only granular fertiliser based on organic, ammonium and urea nitrogen. It acts as an excellent early season product, giving the grass a boost after any dormant periods. It has been used to great success after seeding or over-seeding, particularly in sports pitch environments.