Nutrient film technique

History and Design Characteristics of NFT

• Nutrient Film Technique (NFT) was pioneered in 1965 by Allen Cooper in England.
• An ideal NFT system has a shallow recirculating stream for adequate air exposure to the root mat.
• NFT ensures a balanced supply of water, oxygen, and nutrients for healthy plant growth.
• Design characteristics, like channel slope and flow rate, are common in conventional NFT systems.
• Slopes of 1:30 to 1:40 are sometimes used due to challenges in building a true base for channels.

Description and Flow Rates in NFT Systems

• A properly designed NFT system considers channel slope, flow rate, and length for optimal plant growth.
• NFT systems provide the necessary conditions for healthy plant growth and higher yields of quality produce over extended periods.
• General guidelines suggest a flow rate of 1 liter per minute for each gully in NFT systems.
• Flow rates beyond extremes can lead to nutritional problems, and depressed growth rates may occur in channels exceeding 12 meters in length.
• Care is needed to maintain hygienic conditions and avoid heavy metal contamination in NFT systems.

Lettuce Cultivation in NFT Systems

• Lettuce is the most commonly grown crop in NFT systems.
• Popular lettuce varieties for NFT cultivation include ‘Ostinata, ‘Flandria, ‘Cherokee, ‘Ruby Sky, ‘Vulcan, and ‘Rex.
• With proper inputs and conditions, a 5-to-6-ounce head of lettuce can be obtained in 35 days.
• Lettuce seedlings are typically transplanted into NFT channels after developing 3 to 4 true leaves.
• Lettuce yield and productivity are significantly influenced by light intensity in NFT systems.

Potato Minituber Production in NFT Systems

• Potato minitubers are maintained using tissue culture and micropropagation methods.
• NFT and aeroponic systems are commonly used for minituber production.
• Minitubers are planted in the field 6 to 14 months after harvest, with the first crop of field-grown potatoes replanted to generate more potatoes.
• Tissue culture plants may perform poorly when directly planted into field soil.

Additional Resources and References

• Cooper, Allen (1979). ‘The ABC of NFT’. London: Grower Books.
• Resh, Howard (2004). ‘Hydroponic Food Production’. CRC Press.
• Barbosa, G.; Gadelha, F.; Kublik, N.; Proctor, A.; Reichelm, L.; Weissinger, E.; Wohlleb, G.; Halden, R.; Barbosa, G. L. (2015). Comparison of Land, Water, and Energy Requirements of Lettuce Grown Using Hydroponic vs. Conventional Agricultural Methods. Int. J. Environ. Res. Public Health.
• Frost, Groves, and Charkowski. (2013). Integrated Control of Potato Pathogens Through Seed Potato Certification and Provision of Clean Seed Potatoes. Plant Disease.

Nutrient film technique Data Sources