Bokashi success for Cornish farm

Inspiration from Japan has helped Cornish beef and sheep farmers Bill and Suzanne Harper maximise their grass production and reduce nitrogen use. We spoke to Bill to find out more.

Paying close attention to grassland management has been a focus for the Harpers in recent years. To this end, the first-generation farmers have successfully introduced herbal leys and developed their use of rotational grazing with close attention to grass growth via plate meter readings.

The 222ha Trepoyle Farm in North Tamerton is home to 125 suckler cows and 350 breeding sheep. Bill and Suzanne also rear 100 calves from a local dairy farm each year. Always looking to increase his knowledge of grassland management, Bill was intrigued to read about ‘bokashi’ in the farming press.

Bokashi is the Japanese name given to the process of creating compost through fermentation. Although the exact origin of the concept is unclear, it was named by a professor at the University of Ryukyus, Okinawa, Japan, who first commercialised the concept.

An impressive alternative to chemical fertilisers

Manure and straw from overwinter housing is first treated with 1% crushed seashells to reduce its pH, before an inoculant is applied to stimulate fermentation. The manure is then stacked outside, covered in sheeting and left to ferment for eight to ten weeks. Unlike traditional composting which is an aerobic process requiring oxygen, bokashi is an anaerobic process, taking place without oxygen.

The resulting compost is full of bacteria, yeasts and sugars, as well as organic matter and nitrogen. “All goodies for the land,” says Bill, who believes he is the first farmer in Cornwall to produce and use bokashi. “It converts farmyard manure into a more digested plant-friendly product.”

The results have been impressive, says Bill. “Its persistence was what really impressed me. Chemicals give a flush of growth and then nothing, but with bokashi the grass grows persistently for three months. It could not come at a better time with fertiliser prices as they are.

“I also like that it shatters quickly so we can graze the land again after 21 days, unlike other manure applications which sit on the ground. I’m very keen on it, so we will be doubling the quantity we make this year to 300 tonnes.

“Everything in the grazing platform will now have one bokashi dressing in July or August,” says Bill. “It has become absolutely critical to our system.”

Image credit: Emily Fleur Photography


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