NTU Scientists Use Discarded Hair in New Farming Growth Medium

Salad greens grown from hair? Scientists from Nanyang Technological University, Singapore (NTU Singapore) have developed an urban farming growth medium, called hydroponics substrates, by extracting keratin from discarded human hair.

Crops are grown without soil in hydroponics, which use a substrate instead to act as “support and reservoir” for water and nutrients. According to a press release by NTU yesterday, the research team tested the keratin substrates on microgreens and leafy vegetables, such as arugula leaves and bok choy.

The research team made use of discarded hair from salons to extract keratin, which they then mixed with cellulose fibres and dried into a spongy substrate. NTU added the keratin-based substrate is sustainable, biodegradable, and eco-friendly, and its yield is "comparable to materials currently available on the market, according to laboratory tests."

A gram of human hair is capable of producing three blocks of substrates of around 1.5 centimetre by 1.5 cm by 3 cm in size, about as small as an ice cube.

Professor Ng Kee Woei, research lead and associate chair at NTU’s School of Materials Science and Engineering (MSE), said the plants grew longer roots in the keratin-based substrates as compared to commercial phenolic foams.

"[It] is a promising sign that vegetable roots can better penetrate keratin-based substrates and more effectively absorb nutrients released from the substrates," Ng was quoted as saying.

Professor Hu Xiao from NTU's MSE also boosted the keratin-based substrates' nutritional content by adding nano-nutrients like copper in them.

The researchers' keratin substrate can last between four to eight weeks and produces no waste. As keratin can be extracted from other farm biowastes like wool, horns, hooves, and feathers, Ng believes it can be utilized to manage farm waste.

"Since keratin can be extracted from many types of farm wastes, developing keratin-based hydroponic substrates could be an important strategy for recycling farm wastes as part of sustainable agriculture," said Ng.

The researchers' study was published in the peer-reviewed scientific journal ACS Sustainable Chemistry & Engineering.