Weeds used for good in tree establishment
By Charles Abel
TREES ON SET-ASIDE
farmers weekly readers qualify for a £5 discount for a conference examining all aspects of planting trees on set-aside, to be held at the NAC, Stoneleigh, Warwicks, on Thurs, Oct 12. Reduced prices are £20 for RASE members and £25 for non-members. Contact the RASE: 01203-696969.
TREE establishment without the hassle of weed control and fencing against deer and rabbits, yet with the scope for a small profit after five years.
If it sounds too good to be true, you havent heard of Temperate Taungya.
The technique was pioneered by Joe Watson of Cirencester-based Cotswold Estate Services (Forestry), who has also patented the approach. The name is derived from a Burmese re-afforestation technique.
At its heart is the idea that weeds protect developing trees, rather than compete with them. "I know that turns most forestry principles on their head, but provided you keep perennial weeds out, it works," claims Mr Watson.
By sowing tree seeds with the preceding arable crop a high population of young seedlings is established. Once the nurse crop is harvested the long stubble provides further protection, ensuring up to 10,000 trees/ha (4000/acre).
So, unlike a conventional plantation where trees are planted to a stand, high losses can be tolerated without endangering the woodland grant scheme target. That is 1100/ha for regenerated plantings – half the planted tree target.
Mr Watson is convinced the weeds encourage sapling growth, helping them reach 30-45cm (12-18in) within three years to qualify for the second instalment of woodland grant scheme money.
Most spring cereal can be used, with the husbandry of the arable crop unaffected, apart from avoiding a herbicide after Apr 15.
The economics look attractive. A typical 3ha (7.4-acre) plantation, which could now count towards the flexible set-aside requirement of arable land, would cost £2850 to plant. That compares with traditional planting cost of £8030 – £6600 for planted, staked, guarded trees, plus £770 for two sprays and £660 for administration, reckons Mr Watson.
The conventional plantation would then attract £2385 as 70% of the planting grant, plus £1800 for a better land supplement and £750 from the farm woodland premium scheme. Taungya grant income would be similar, although the planting grant is discretionary, amounting to £2034. But there would also be the spring crop – typically generating £1223 net, including straw and area aid.
That means in year one the taungya is almost £3000 in the clear, whereas the conventional approach lingers £2645 in the red.
In the following five years spraying and planting-up costs could top £4000 in the conventional example, whereas Cotswold Estate Services would not spray and offers a guaranteed stocking and maintenance fee of £3000, again keeping the right side of the typical £5000 grant income.
"So far, interest in taungya has run at about 20ha a year. But with the set-aside link and clarification of rules the prospects look good," says Mr Watson.
• Sow broad-leaved tree seeds with previous crop and leave plants in stubble ex-harvest.
• Up to 10,000 trees establish, giving good scope for losses, without beating up costs.
• Weeds encourage growth and protect trees from weather.
• Rabbit and deer tolerated.
• Scope to thin to suit biomass or timber need later.
• Offers small profit instead of loss after establishment.
Undersowing high populations of trees into the arable crop before set-aside gives saplings a good start, says Joe Watson. Later weed growth need not be controlled – it protects plants and encourages stem growth, he claims.