Seabrook on...Benefits of Controlled-release fertilisers under threat

The vote to leave the EU looks to be the right decision when facing the difficulties of getting a score and more countries to agree on policy.

Take for example the new draft criteria for biodegradable polymers that, if brought in next year as proposed, will eliminate all the controlled-release fertiliser (CRF) products used in the UK and Europe.

It is too easy to take for granted the steady improvements science brings to our everyday lives and in the case of CRFs the remarkable developments over the past 50 years.

They are now fundamental to UK container, amenity and food crop care. Indeed, the much improved results obtained by home gardeners growing in containers is without doubt the result of slow-release plant feeding.

They are made by enclosing up to 12 different nutrients in a polymer resin with tiny pores that open with heat expansion to let in moisture and close when temperatures drop.

The higher the soil and compost temperatures, the more water moves in and the greater the release of plant foods by osmosis. Currently there are products available with release times of six weeks, three-to-four months, five-to-six months, 12-14 months and up to 18 months.

They allow nutrients to be added to composts at mixing to be metered out through the growing season, reducing the costs of repeated application. The new criteria require decomposition in two years and rapid break down would mean a surge in the release of fertilisers, damaging plant roots and increasing nitrate run-off.

Growers have to meet the requirements of the Water Framework Directive and the new directive would mitigate this by increased leaching into ground and surface water. If my information is correct the new draft regulations appear to have been translated from the use of polymers for other purposes and including mulching films.

While the industry accepts the need to be environmentally friendly with the products it supplies, in the case of CRFs it will take time to develop a casing that is both biodegradable and able to deliver plant foods in the right quantities for the climatic conditions over a period of months.

Several growers and retailers have provided detailed information about the use and benefits of CRFs in horticulture in support of an industry counter proposal being submitted to the European Commission. Let’s hope that this initiative, in conjunction with similar feedback from other European countries, has the desired effect in changing their minds.

Peter Seabrook is a gardening writer and broadcaster


Before commenting please read our rules for commenting on articles.

If you see a comment you find offensive, you can flag it as inappropriate. In the top right-hand corner of an individual comment, you will see 'flag as inappropriate'. Clicking this prompts us to review the comment. For further information see our rules for commenting on articles.

comments powered by Disqus

Read These Next

Business planning - Post-Brexit recruitment

Business planning - Post-Brexit recruitment

A good human resources strategy can help to ensure that you have enough of the right staff at the right time, Neville Stein advises.

How will apprenticeship levy impact horticulture business?

How will apprenticeship levy impact horticulture business?

Next month's introduction of the Government apprenticeship levy could offer good value for money for horticultural businesses, Rachel Anderson discovers.

Loropetalum

Loropetalum

Colourful flowers and stunning foliage are great rewards for growing this often unfamiliar plant, says Miranda Kimberley.


Opinion: Edwards On... Plant supply and health

Opinion: Edwards On... Plant supply and health

Increasingly, and rightly, plant health/biosecurity is being recognised as something of which all of us involved in plant supply must be aware.

From The Editor - Prospects for the year ahead

From The Editor - Prospects for the year ahead

Making predictions about the future is a risky business in the best of times. Throw in a year when the UK is set to begin the formal process of leaving the EU and all bets are off. Despite this, the HW team has prepared our biggest-ever preview of the year ahead.

According To Edwards ... Why horticulture needs a different dialogue to farming

According To Edwards ... Why horticulture needs a different dialogue to farming

The Government will always look on "horticulture" as a sector within "agriculture" and, when the trade effectively gets its message across, the Government recognises "nursery stock" as a non-edible subset of horticulture.


Follow us on:
  • Facebook
  • LinkedIn
  • Twitter
  • Google +
Horticulture Jobs
More Horticulture Jobs

Pest & Disease Tracker bulletin 

The latest pest and disease alerts, how to treat them, plus EAMU updates, sent direct to your inbox.

Sign up here

Are you a landscape supplier?

Horticulture Week Landscape Project Leads

If so, you should be receiving our new service for Horticulture Week subscribers delivering landscape project leads from live, approved, planning applications across the UK.