The New Science and Practice of Hydroponic and Hydro culture Nutrient Film Techniques
[Bottom feed irrigation techniques]
According
to Mathew Norton
The Nutrient Film Technique is a bottom feed
irrigation technique that provides a continuous gradient of either pure or
nutrient enriched water to the root ball of a plant for improved root cell
osmosis and gas exchange. The
Nutrient Film Technique can refer to an active [use energy, moving] or passive [no energy] body
of water and is equally effective because it allows the xylem vessels of a plant
to transport greater volumes of water, salts, carbon dioxide and oxygen, for
increased plant photosynthesis and respiration.
Plants thrive with permanent root ball immersion in water, and providing the stem base of the plant is not immersed in water for any lengthy period of time root rot will not occur. In open garden systems [outdoor soil gardens] where only partial root ball immersion can be achieved moisture spreading techniques must be used to provide effective overall medium saturation and optimize growth rates. To achieve this, moisture spreading mediums such as sand, perlite, gravel, vermiculite, expanded clay, rock wool, peat moss, sphagnum moss, or nylon matting are used to spread moisture to the outer regions of the root ball area. This must be done prior to planting in a garden bed. The body of water in the water-dispensing vessel must be located in close proximity to the root ball [approx 6 inches], and for good results must remain at a constant level and must never be allowed to run dry. If the well does become empty, juvenile plants will rapidly show signs of stress, become diseased, lose growth vitality and eventually die. However, if water and nutrition factors can be reliably controlled [via a micro valve], excellent plant health, growth rates, and bloom are achieved.
