New System Shows Benefits Of Deep Root Irrigation

A locally developed irrigation system designed to transport water directly to plants’ roots and thus eliminate evaporation has achieved outstanding success in trials.

- Annelie Coleman

Designed specifically for South African conditions, the NOVAP Sub-Surface Water Diffuser facilitates deep root irrigation and supplies water directly to a plant’s root system. As no water is exposed to the soil surface, moisture loss through evaporation is dramatically reduced.

Ferdinand de Klerk, NOVAP’s brand manager, says the system was developed and patented in Cape Town by Jan Nortjé, an inventor who strives to provide practical solutions to specific problems. “His insight into technical challenges has led to the registration of various international inventions,” says De Klerk.

Development started in 2013, and the irrigation system was launched in April 2017. Trials have shown water-use reduction of as much as 70%. In a Western Cape trial on 1ha of table grapes, a total water saving of 56,8% and a yield improvement of 31,5% were recorded after the change from micro irrigation to deep root irrigation.

The NOVAP system is suitable for any type of tree or shrub, including roses and other perennial scrubs with root systems deeper than 150mm. Fruit trees, vineyards, as well as nuts and date trees respond particularly well to this type of irrigation, according to De Klerk.

WATER TABLE AT ROOT LEVEL

The system consists of a compact plastic unit installed at the optimal depth for specific crops, typically 250mm. It supplies water and liquid fertiliser at a steady rate for maximum uptake, and artificially creates an underground water table at root level.

Depending on the soil type, a hydrated bulb with a radius of up to 600mm is formed 1,2m deep. The capillary movement of water allows the moisture to rise 120mm to 150mm above the system.

(Capillary action is the ability of a liquid to flow sideways and even upwards in narrow spaces without the assistance of external forces.)