greenhouses I shade net I hydroponics I aquaponics
The ever-popular cocopeat still used in hydroponics systems
A
close-up look at the cork-like leader in coir media, having secured cells of the pith and fibrous supply to their seven factories in Sri material reveals a porous Lanka, India and Malaysia for a number of structure, which provides an years into the future. Galuku have done enormous reservoir for holding water. an enormous amount of research and Pore space amounts to about 90% of the development, specifically in commercial material volume. hydroponic horticulture, and today growers are achieving the same yields in Coco peat as a result, has a high water coco peat as what they do in rock wool. holding capacity (WHC) and a high water retention efficiency (WRE), while at the A wide range of products is available same time maintaining a high air-filled to suit the growers needs in whatever porosity (AFP). It is this climate they grow unique combination, throughout the world, Coco peat has a high which makes it a good water holding capacity including for organic hydroponics growing growers. (WHC) and a high water medium. After drying Coconut coir has been retention efficiency it also rewets relatively available as a growing (WRE), while at the easily. medium for a number same time maintaining of years, with the initial The high lignin content a high air-filled of the material ensures grade available being a that it maintains a porosity (AFP). It is this fine material designed for good physical stability use in seed raising and unique combination, with a very slow for basic potting mixes. which makes it a good decomposition process, This grade had a very hydroponics growing which means that it can high WHC, a high salt medium. be used for extended content and a low AFP periods of time and for (10-12%) which made multi-use applications, making it very it unsuitable as a hydroponic medium cost effective. the management of the water content is too difficult and there is too little air for The supply of coconut coir is reliable oxygenation of the root zone. due to the size and organization of the coconut industry with major coco peat The lack of success with this material suppliers such as Galuku, the world resulted in a resistance to the use of
It is well-known that Coco peat is a derivative of the husk of the coconut - the fruit of Cocos nucifera trees. Coco peat consists of coir pith, coir fibre and husk chips in proportions, blended specifically for different applications in horticulture. It has unique properties, which make it highly suitable as a hydroponics growing medium. coco peat as a substrate, a misplaced fear, which still exists in some quarters today. AFP refers to the air space within the medium when the medium is at full water holding capacity (as a %). WHC is the volume of the medium that is occupied by water at full water holding ability (measured as a %). The ideal AFP and WHC for hydroponics are 35-45% and 40-60% respectively, depending upon the climate and crop grown. So, even at full WHC water-logging does not occur in the correct blends. Reputable suppliers have developed high performance grades of coco peat which bear little resemblance to the original material with blended grades having AFP and WHC tailor-made to suit requirements. Controlled steering of the growth of plants is now possible with the grower able to manage water and air content on a daily or seasonal basis, with increased production and water savings a reality. Containment systems with UV protected plastic such as Easyfil planter bags, Hydro CS slabs, Gerbera discs and the like have also been developed to reduce labour costs in growing systems and to improve hygiene. Source: M von Holdt
Undercover farming I
September/October 2020
I Volume 17 No 5 9
