Trickle system scores highly inirrigation trial
By Edward Long
TRICKLE irrigation has given a Suffolk farmer higher yields of potatoes with a more uniform pre-pack sample. But the question now is how rapidly to extend the high-tech approach to replace rainguns and a boom irrigator.
Philip Mayhew of AW Mayhew Farms tried trickle for the first time on part of his 60ha (150 acres) of potatoes at Home Farm, Wolverstone, near Ipswich, this year.
Other crops on the 1000ha (2500 acre) lightland farm which is run with father Jim and brothers Chris and Geoff include cereals, sugar beet, linseed and spring beans.
Neutron probes determine when to start using the four hosereel rainguns and the boom irrigator. The aim is to maintain a maximum SMD of 1cm (0.4in) at tuber initiation for scab control then to relax it to 2.5cm (1in) for the rest of the season.
"We decided to try trickle this year because we felt that with water use restrictions likely in future it was time to look for more efficient ways of using this valuable resource," Mr Mayhew says.
He is also chairman of Hereward Growers, an 18-member group supplying Fenmarc which packs for Asda. "Some members have used trickle successfully, so I felt it was our turn to assess its potential value. We are not short of water, but want to use it wisely."
Trickle was used on 3.6ha (9 acres) of Maris Piper grown in an awkward shaped field bordered on two sides by public roads, which make it difficult to irrigate without offending neighbours. T-tape was laid into the top of every 90cm (36in) wide row at planting. A close hole spacing of 20cm (8in) was chosen to ensure efficient scab control.
"It was a lot easier to manage than anticipated, and highly effective. We lifted 22t/acre of pre-pack quality tubers across the whole field. What impressed me was the uniformity of yield and evenness of the sample."
In recent seasons variable output from raingun irrigation, particularly in Nadine, has been a frustration. "Wind upsets the water distribution pattern and in some parts of the crop we lift 35t/acre, but in others only 25t."
Using trickle also reduces blight pressure, he notes. Watering soil rather than foliage reduced canopy humidity and less travel through the crop cut disease establishment.
"The cost of disposable T-tape was £170/acre. So with the depreciation share of the valves and filters the overall cost was about £200/acre. But it is important when growing for packing to achieve good uniformity and tuber quality across the whole field," Mr Mayhew says.
"This year when a chipping sample of Piper was worth £80/t a pre-pack sample was worth at least twice as much. So T-tape could play a valuable role in helping us to grow a good crop. We plan to use it again next season for all or part of our 30 acres of Piper." *
• Efficient water use.
• More uniform sample.
• Expansion plans for 1999.
Dont miss the national irrigation event – Water for Farming 98.
If you are in the business of exploiting limited water supplies to produce top quality potatoes and vegetables this is the event for you. Organised by farmers weekly and Fusion Events it takes place at Newark Showground on Tues Nov 10.
All the UKs top irrigation equipment will be on show, plus the most up to date advice. A detailed seminar programme will address issues including licensing, storage and efficient application. Tickets are priced £5 each, but are available free by ordering in advance from Fusion Events, PO Box 58, Kendal, LA9 7GD (01539-734725, fax 01539-740485 or e-mail firstname.lastname@example.org).