To continue to expand, the sector will have to either invest in more water storage or use less per tonne of crop.
Fortunately, a new demonstration centre at NIAB-EMR is not only intended to show how this latter can be achieved but also to prove that other improvements to the crop and resource efficiency can be accomplished at the same time.
Explaining the rationale for the Water Efficient Technologies (WET) Centre, project leader Paul Dracott told growers that, as things stand, they can extract as much water as they need for trickle irrigation because it has been seen as an efficient use of water.
"But they didn’t bargain on the levels of growth we have seen," he said. "That’s starting to put pressure on rivers at peak periods in summer. So now the plan is that you are all going to be licensed trickle irrigators, probably at a level that is capped at the 2016-17 level.
"So that’s it. We can forget 10-20% growth a year without changing how we use water. Either you store it in winter, which is expensive though a lot of growers are still doing it, or improve your water use efficiency, something we have worked on here at East Malling for the last 10 years."
NIAB-EMR’s ongoing monitoring of commercial growers’ water use has shown a three- to four-fold difference between the most and least efficient, said Dracott. "That’s a phenomenal opportunity for growers to improve water-use efficiency. If you’re at the bottom, we can now show you how to improve."
NIAB-EMR department leader Dr Mark Else, who has been responsible for much research on the topic, tells Horticulture Week: "Precision irrigation is getting the right amount of water to the right place at the right time in order to optimise resource use. There can be a 13-fold difference in that use from day to day.
"Some varieties are sensitive to unplanned deficits, others not. Over the last 10 years we have gained an understanding of plants’ response to varying levels of irrigation, which has already meant working with the partners in technology and telemetry demonstrated here."
More than 20 commercial trials in recent years "have already shown positive results in both water and fertiliser use", he adds. "We can show here that as well as saving 20% on water use, you can cut your energy use as you are pumping less water around," bringing savings estimated at £2,400 per hectare per year.
"Not only that, by optimising water availability to the plant, you can get a more consistent crop and a higher class-one yield, with better firmness, flavour, shelf life and phytonutrient content," says Else. "There are so many advantages beyond just using less water, and this shows how it can be integrated on a commercial scale."
Although the focus of the WET Centre is on the EMR-bred Malling Centenary variety, Else says: "Different varieties respond differently to things like water deficit, so you need to develop bespoke regimes for each variety."
Initially the new centre will trial the Precision Irrigation Package (PIP) that monitors moisture levels and irrigation performance in real time and provides fully automated irrigation to maintain moisture at precise levels and optimise water use.
"Growers need the confidence that they can accurately control the irrigation of their crops and avoid the impact that over or under-watering can have on the consistency of fruit," Else explains.
Factoring in the cost savings, and assuming a 5% improvement in yields, the WET Centre’s partners estimate the system would benefit a grower producing 20 hectares of strawberries by £6,600 per hectare per year, or an increase in net income over three years of £396,000.
Wet Centre partners and further support
- Grower group Berry Gardens Growers
- Delta T Devices
- irrigation specialist Netafim UK
- New Leaf Irrigation
- Growing media supplier Cocogreen
- Variety marketer Meiosis
- South East Water
- Kent County Council
Cocogreen commercial director Thomas Ogden says: "We are looking to expand our support service to growers and will use this as an education resource, inviting staff here, providing data and using that to support decision-making."
Officially opening the facility, farming minister George Eustice said: "A lack of water is presenting itself as a challenge around the world. The government is having to look at tricky issues around water abstraction, and part of the solution will be technical advances that allow more precise use of water. This is critically important for soft fruit in particular."
The Government’s proposed reforms to the abstraction regime include measures to better link abstraction to water availability and to introduce quicker and easier trading of abstraction permits. It says it wants to use a "twin-track" approach of managing both water supply and demand.
Currently, 6% of freshwater bodies in the UK are reckoned to be over-abstracted. Yet demand for abstracted fresh water is expected to rise by 9% over the next 30 years, due mainly to population growth, which is forecast to be concentrated in areas already classified as "water stressed", particularly in the South East, where fruit production is concentrated — a problem likely to be further exacerbated by climate change.
The Government has so far avoided committing to a timetable, but phased implementation is expected in the early 2020s, with abstractors previously exempt from licensing, including trickle irrigators as well as mines, quarries and ports, among the first to be integrated into the new system.
A Defra report last year warned: "Indirect effects of ending exemptions could include increased food imports and impacts on jobs and production, if agriculture and mining operations move overseas because of uncertain future water supply."