Planting and Growing Short Rotation Coppice
Picture 1: src ready to harvest (defra)
Best Practice Guidelines 18 December2007
For Applicants to Defra s Energy Crops Scheme
Contents
1. Introduction
2. Why grow energy crops?
3. Eligibility to energy crops scheme
4. What is SRC?
5. Where to grow SRC?
6. Planting
7. General crop management
8. Calendar of activity
9. Harvesting
10. Yield
11. Removal of SRC
12. Carbon Savings
13. Energy value
14. Further environmental considerations
15. Other species for SRC
16. Abbreviations
17. References
18. Contacts
1. Introduction
This booklet explains the energy crop Short Rotation Coppice (SRC) e.g.
willow or poplar and gives guidance for planting within the Rural
Development Programme for England 2007  2013. It gives information on
the most appropriate location, land preparation, planting techniques and crop
management required to grow SRC as a commercial crop for energy use.
Ongoing current research and best commercial practice are also summarised.
The guidance concentrates on the cultivation of willow and poplar SRC, but
also contains a summary of cultivation of alternative traditional coppice
species which are now eligible for support under the Energy Crops Scheme
(ECS) over a longer coppicing rotation. Updates to this information will be
made available via the Forestry Commission Internet pages, so make sure
you visit them to view the latest online versions. They can be found at http://
www.forestry.gov.uk/forestry/infd-6dfk2u This booklet should be read in
association with the Energy Crop Scheme Establishment Grant Handbook
available from Natural England at http://www.naturalengland.org.uk/planning/
grants-funding/energy-crops/default.htm.
There is further information on short rotation coppice available in the Forestry
Commission Information Note  The establishment and management of short
rotation coppice  a practitioner s guide (Tubby and Armstrong, 2002).
2. Why grow energy crops?
The UK Government is keen to encourage sustainable and responsible
growth in the energy crop market in response to the need for atmospheric
carbon dioxide (CO ) abatement.
2
Government targets, aspirations and long-term energy policy are contained in
the Energy White Paper published in 2007, which states  there is a case for
continuing to support energy crops so as to promote the development of an
effective domestic supply chain for this valuable resource.
www.dti.gov.uk/energy/whitepaper/page39534.html
The market for energy crops which are grown specifically to be harvested and
burnt in power stations, combined heat and power (CHP) units or heating
systems is becoming established in the UK. The number of power and CHP
projects developing across England which utilise biomass, including energy
crops such as SRC is increasing.
The UK Biomass Strategy published in May 2007
[www.defra.gov.uk/environment/climatechange/uk/energy/renewablefuel/pdf/u
kbiomassstrategy-0507.pdf] acknowledges the importance of fuels sourced
from biomass grown in the UK in tackling climate change. It suggests that
350,000ha could be suitable for growing perennial energy crops once a
number of constraints have been considered. Our aim is to deliver an
expansion of biomass production with an enhanced, sustainable approach to
land management which will deliver multiple environmental benefits. Biomass
production and processing can be carbon neutral (the CO released when it is
2
used to produce energy being offset by the CO it consumes when growing)
2
and will therefore have a significant role to play in meeting both the EU target
of 20% renewable energy by 2020 and the UK target of at least 60% cuts in
carbon dioxide emissions by 2050. Biomass can also be used to produce
heat, at a range of industrial or domestic scales, electricity and potentially
second-generation biofuels.
Grants
By contributing to the establishment of a perennial crop the ECS aims to
encourage growers to invest in the biomass market and increase the volume
available to meet the EU target of 20% renewable energy by 2020. The
Energy Crops Scheme (ECS) is part of the Rural Development
Programme for England (RDPE). Applications for grants to assist in
the establishment of this crop can be made to Natural England.
Full details of the grant schemes can be found in the ECS booklet
 Establishment grants handbook at
www.naturalengland.org.uk/planning/grants-funding/energy-crops/docs/ecs-
handbook.pdf
3. Eligibility to energy crops scheme
1. Generally, all land in England is potentially eligible for entry into the
scheme, but there are exceptions for:
" land already planted with woodland or coppice,
" land already planted with miscanthus,
" common land,
" Land in some other schemes  see Section 3
" Sites of Special Scientific Interest (SSSIs) Scheduled
Monuments (SMs) Local Nature Reserves, National Nature
Reserves, Registered Battlefields, Special Areas of
Conservation (SAC), Special Protection Areas (SPA), World
Heritage Sites and Ramsar sites.
Forestry Commission regional staff will carry out environmental appraisals on
all SRC applications. The outcome will be a recommendation to the Natural
England ECS Administration Unit. A range of environmental factors will be
considered, including: landscape, historic environment, soil, biodiversity,
access and amenity. For the historic sites and landscapes, the Forestry
Commission will consult with the local authority Historic Environment Record
(HER) and English Heritage where statutorily protected sites are involved, to
assess the impacts of any proposed planting scheme. There are certain areas
that are likely to be considered unsuitable for the planting of energy crops,
including World Heritage Sites, Scheduled Monuments, Registered Historic
Parks and Gardens, Registered Battlefields, on former water-meadows and
within Conservation Areas. Impacts from the crop that are considered include
potential damage from plant roots, planting, harvesting, crop removal
operations and changes to water levels. Shapes of fields, fencing and access
are also considered in deciding eligibility.
4. What is SRC?
SRC (short rotation coppice) consists of densely planted, high-yielding
varieties of willow or, less frequently, poplar, harvested on a 2  5 year cycle,
although commonly every 3 years. SRC is a woody, perennial crop, the
rootstock or stools remaining in the ground after harvest with new shoots
emerging the following spring. A plantation could be viable for up to 30 years
before re-planting becomes necessary, although this depends on the
productivity of the stools. The ECS also permits the cultivation of slower-
growing traditional coppice species on a longer rotation of up to 15 years.
These include Ash, Alder, Hazel, Silver Birch, Sycamore, Sweet Chestnut and
Lime.
SRC is planted in the spring using planting material produced by specialist
breeders and equipment specifically designed for the purpose. The SRC will
grow rapidly in the first year reaching up to 4m in height. During the winter
after planting the stems are cut back to ground level to encourage the growth
of multiple stems i.e. coppiced. Generally 3 years after cutback and normally
during the winter, the crop is harvested. SRC is harvested with equipment
especially designed or adapted for the crop. Most operations other than
planting can now be completed using conventional farm machinery. In the UK,
yields from willow SRC at first harvest are expected to be in the range 7-9
oven dry tonnes per hectare per year (odt/ha/yr depending on the standard of
ground preparation and weed control and on annual variations in weather
conditions. Yields should also increase at second and third harvests up to
8-12 odt/ha/yr on better sites. Poplar SRC generally does not respond to cut
back in the same way as willow. Many poplar varieties show strong apical
dominance, often producing only 1 or 2 main stems even after cut back.
However, poplar can produce yields that are comparable with willow on
suitable sites.
Picture 2 SRC
5. Where to grow SRC
Site selection
A general indication of where to site SRC can be found by using the
opportunity maps on the DEFRA website.
www.defra.gov.uk/farm/crops/industrial/energy/opportunities/index.htm. These
maps offer indicative advice only as individual sites may offer substantially
different growing conditions e.g. in terms of water availability, exposure etc.
Local Impact
As a perennial crop, SRC is likely to be in the ground for up to 30 years and
can reach 7-8m in height prior to harvest. Care must be taken to avoid
overhead or underground cables and other services. Its impact on the local
landscape, ecology, archaeology and public access must be considered
alongside the operational parameters. Careful siting of open ground can
minimise immediate impacts, such as having field margins adjoining
neighbours land. Hard access must be available for all machinery involved in
establishing and harvesting the crop. Gate widths should be at least 4.5m but
it is recommended that if new gates have to be installed they should be up to
7.2m in width. Bridge height or weight restrictions should also be considered
where necessary. Ideally areas for transferring and storing the harvested crop
should be adjacent to the coppice as extra transportation of this bulky crop
can reduce the environmental benefits.
Further information and advice can be found in the Joint Character Area
statements at www.countryside.gov.uk/LAR/Landscape/CC/jca.asp. Under the
ECS all application sites are assessed and consultation takes place to ensure
there will be no significant adverse impact on the environment.
Picture 3  SRC growing in the UK (Marian s picture)
Environment
The key determinants of SRC yield are water availability, weed control during
establishment, light and temperature. Willow SRC will produce good growth
where there is sufficient soil moisture available within 1metre of the soil
surface. It can withstand seasonal flooding but not prolonged waterlogging.
Where land is prone to flooding most years, the willow will survive but
consideration must be given to operational requirements, particularly the need
to harvest (c.f. the Cross Compliance Handbook GAEC3
www.rpa.gov.uk/rpa/index.nsf/0/edd25767705ebd0b802570d1005898b4/$FIL
E/XC%20Handbook.pdf). [ Annual rainfall of over 600mm is ideal. A maximum
elevation of 100m above sea level is recommended unless the site is
particularly sheltered.
SRC can be established on a wide range of soil types from heavy clay to
sands. This includes sites reclaimed from gravel extraction and colliery spoil.
Clay and/or sandy loams that retain moisture but are well aerated are ideal
soils. Establishment may be slow on heavy soils (with a high clay content) as
they tend to be cold in spring although, once established, SRC grown on
these soils can be highly productive. Where compaction may prove to be a
problem, sub-soiling to a depth of 40cm could be necessary to ensure
maximum root development. Soil pH should be in the range 5.5  7 for willow
and 5.5  7.5 for poplar, and ideally a P and K index of 2 should be targeted.
Cultivation details for other species can be found in Section 13
Erosion
Another factor to consider is soil erosion. Compared to many crops, SRC has
large areas of open ground within the crop during establishment. On light,
sandy soils this can lead to wind erosion of the soils and also some damage
to the newly emerged shoots due to abrasion. On sloping sites, soils can be
eroded following heavy rain, however this can be reduced by ploughing and
planting rows across the slope (following the  Controlling Soil Erosion
guidance www.defra.gov.uk/environment/land/soil/pdf/soilerosion-
combinedleaflets.pdf and the  Good Agricultural and Environmental Condition
guidance
www.rpa.gov.uk/rpa/index.nsf/0/edd25767705ebd0b802570d1005898b4/$FIL
E/XC%20Handbook.pdf). Once established, however, soil erosion is likely to
be less than if the area is planted with arable crops as the root mat formed by
the growing trees can help stabilise the soil.
Willow roots, which are fibrous in nature, may penetrate and damage field
drains. When choosing a site, the life of the drainage system should be
considered in relation to the expected life of the SRC plantation. Most of the
willow roots, however, grow within the top 20/30cm of the soil with the main
structural roots growing horizontally (Crow and Houston, 2004).
Design
To be eligible for grant the proposed site must be at least 3ha in total,
although this can be made up of smaller plots. To ensure economies of scale
for all field operations larger plantations are better, however this may result in
a loss of habitat diversity and have a detrimental effect on local scale
biodiversity. The most appropriate field shapes are those that minimise the
need for short row lengths or require no changes in direction during field
operations. Choosing fields that can be harvested economically is of critical
importance. For ease of operations the ideal site would be flat or with a slope
of no more than 7%. It is strongly recommended that the slope of the field
should not exceed 15%.
6. Planting
Pre-planting requirements
The importance of efficient land preparation for SRC cannot be stressed too
highly. As SRC is a long-term, perennial crop, ensuring ideal conditions at
establishment will reap benefits at first and all subsequent harvests.
Weed control is a critical part of coppice establishment. Complete eradication
of all invasive perennial weeds is essential prior to planting. One or two
applications of a systemic herbicide, applied at the appropriate rate, should be
carried out in the summer/autumn prior to spring planting. Ideally the first
herbicide application should take place in midsummer with a follow-up
application in autumn to control any further flush of weeds. An additional
application just before planting in spring may be necessary on some sites,
ensuring an interval of at least 10, preferably 14 days before soil preparation.
Spring spraying alone is unlikely to be effective with a large dormant weed
population.
If required the site should be sub-soiled to a depth of 40cm to remove
compaction. It should then be ploughed to a depth of at least 25cm and left to
over-winter (c.f Cross Compliance Guidance for Soil Management [section C]
www.rpa.gov.uk/rpa/index.nsf/0/edd25767705ebd0b802570d1005898b4/$FIL
E/XC%20Handbook.pdf and the SPS Soil Protection Review [section G]
www.rpa.gov.uk). Ploughing across any slopes will help to minimise soil loss
(as detailed in the  Controlling Soil Erosion booklet
www.defra.gov.uk/environment/land/soil/pdf/soilerosion-combinedleaflets.pdf).
On lighter land it may be more appropriate to spring plough. Power harrowing
of the site should be carried out immediately before planting. Sludge cake,
well-rotted farmyard manure or other bulky organic manure with a low
available nitrogen content can be incorporated into the soils prior to
ploughing. This is particularly beneficial on light soils where it will increase
moisture retention and help to condition the soil. The Defra Code of Good
Agricultural Practice to protect water, soil and air quality [as amended  these
are currently being revised] must be adhered to when applying organic
manures. In Nitrate Vulnerable Zones (NVZs) the amount of manure applied
should not exceed 250g/ha in any one field over a 12-month period, and
should not exceed the amount of nitrogen required by the crop, to avoid run-
off. Guidance is available on the Defra website at
http://defraweb/corporate/regulat/forms/agri_env/nvz/nvz5.htm
Rabbits, if present, must be kept out of the crop at least during the first two
years and ideally up to first harvest, to allow the crop to mature beyond its
vulnerable stage. Rabbit fencing should be erected to British Standard, buried
and turned out to deter rabbits from burrowing underneath. Defra and the
Department for Business, Enterprise and Regulatory Reform (BERR) have
produced a leaflet on rabbit management techniques for SRC (McKillop &
Dendy, 2000) which is available via their website at http://www.berr-
ec.com/cgibin/priamlnk.cgi?
MP=A^GINT64&CNO=1&SEARCH=rabbit&SORTBY=DESC&REVERSE=1
Planting material
Access to the ECS is not restricted to specified varieties of willow. Poplar
varieties are controlled under the Forest Reproductive Material (FRM)
Regulations. Several varieties have now been bred specifically for use as
SRC energy crops, and selected to ensure high yields, erect growth habit and
resistance to, or tolerance of, disease. Planting a mixture of resistant varieties
reduces the impact of pests and diseases (see Pests and Diseases, section
7)[
European Plant Breeders Rights protect the majority of varieties and crop
harvested on the farm cannot be used as planting material. Further
information can be obtained from suppliers listed at the back of this guide.
" Cuttings: cut fresh from rods and between 18  20cm in length, at
least 9mm diameter (depending on the type of planter used)
SRC is planted as cuttings. Only licensed producers are allowed to propagate
cuttings.. Cuttings are taken from one-year-old material that is harvested
between December and March when the plants are dormant. They must be
either planted immediately or stored at -2 to -4°C, where cuttings will remain
viable for several weeks. Once delivered to the planting site, they should be
kept moist and shaded prior to planting. If cuttings are left in temperatures
above 0°C a break in their dormancy will occur, adventitious roots will develop
and the buds may burst. This will lead to a reduction in water and nutrient
content and consequently reduced viability. Poplar cuttings should have a
healthy bud about 1cm below the top cut; willow cuttings can produce shoots
along the length of the cutting. Other species should generally be grown from
locally-produced seed when available.
Planting should ideally take place after the last frosts but as early as February
if soil conditions allow. Planting can be successful as late as June but late
planting is best avoided as the longer the first growing season the better in
order to take the plants successfully into winter and cutback. Another factor is
that late planting has to rely on planting material from cold store, i.e.
harvested earlier in the year. This will restrict the material available, especially
as cuttings start to lose viability after a few weeks in storage. Late planting is
also more subject to failure from drought in a dry summer.
The site should be rolled immediately after planting to consolidate the soil for
effective herbicide application. Pre-emergence residual herbicide should be
applied within 3-5 days of planting. If the site was previously grassland or
long-term set-aside, leatherjacket control should be applied if large numbers
of larvae are present in the soil. For commercial reasons it is better to apply
the insecticide at the same time as the pre-emergence residual herbicide but
ensure that it is before root or shoot development.
Plantation design
After location, plantation design is one of the key factors that will determine
the environmental impacts of an energy crop. The plantation design should fit
in with the surrounding landscape and advice relating to this can be obtained
from Forestry Commission Guideline Note 2 (Bell & McIntosh, 2001).
Operational requirements must also be taken into account. Headlands of at
least 8m in width are necessary at both ends of the rows to allow for vehicle
turning. Where only one trailer will be available at harvest or the harvester has
an integral trailer, row lengths should be restricted to a maximum of 200m to
avoid the need to reverse along the rows to offload. Where two or more
trailers will be available, row lengths can be longer. However, if liquid sludge
is to be applied using an umbilical system, the maximum row length should be
400m. Applications should not exceed the levels set in the Code of Good
Agricultural Practice, and should be reduced in NVZ and if the land already
has a high level of organic nitrogen. Rides of at least 4m should be left along
the edges of the crop to allow machinery access for beetle control if required.
All these issues will be considered during the assessment of the application.
SRC should be planted in twin rows 0.75m apart and with 1.5m between each
set of twin rows. This spacing allows standard agricultural machinery fitted
with wide tyres to work across the crop. A spacing of 0.59m along the rows
when planting cuttings will give a planting density of 15,000/ha, the
commercial standard.
Picture 4 - Barbara Hilton s 2 weeks post planting
Planting equipment
Willow SRC is planted as cuttings cut fresh from rods by specifically designed
planting machines which can plant 2, 4 or 6 rows in one pass. Rods of
1.5-2.5m length are fed into the planter by 2 or more operatives depending on
the number of rows being planted. The machine cuts the rods into 18-20cm
cuttings, inserts the cuttings vertically into the soil and firms the soil around
each cutting. This method is not recommended for poplar as the point of cut
may not coincide with the healthy bud. 15,000 cuttings per hectare is the
current standard commercial planting density using this method. Lower
density planting may lead to thicker stems and consequently larger chip size.
For small areas of willow planting, or for planting poplar, modified cabbage
planters can be used for planting cuttings directly.
Picture 5  Barbara Hilton s planter  Egedal 5
7. General crop management
Establishment year management
From each cutting 1  3 shoots will arise and reach up to 4m in height by the
end of the first growing season, depending on soil conditions. No fertiliser
should be applied during the establishment year.
The coppice should be monitored carefully for pests, weed growth and
general health during the establishment year. If remedial weed control proves
necessary, a hooded band sprayer, specifically designed for use on SRC,
should be used.
 Beating-up or filling in gaps can be undertaken in the first year after planting
if a low proportion of the cuttings have failed to establish. It should be noted,
however, that partial or complete replanting of poorly established SRC stands
due to lack of ground preparation is an expensive and wasteful exercise.
Growers would be expected to replant at their own expense.
Cutback
During the winter following planting the willow is usually cut back to within
10cm of ground level to encourage the development of the multi-stemmed
coppice. The work should be carried out as late as possible in the winter but
before bud-break, generally late February/early March. Wide flotation tyres
can help minimise rutting if the ground is wet although cutting back when the
land is dry or frozen is recommended if possible. The most effective machines
are modified mowers/reapers as these give a clean cut to the stems. Standard
drum or disc mowers can be used but they need to be kept sharp and moved
forward slowly to avoid root damage or lifting of young plants. A contact
herbicide should be applied after cutback to control those weeds that have
grown during the establishment year. It is important that the herbicide is
applied before coppice bud-break otherwise the crop will be damaged.
Generally the use of systemic/translocated contact herbicides should be
avoided due to the risk of crop damage although some have been shown to
be safe when applied before bud-break. The use of species-specific targeted
sprays can be useful. Another option is to use a mix of contact and residual
herbicide after cutback. The addition of the residual herbicide helps maintain
weed-free conditions until canopy closure. Again, if used, this mix must be
applied before bud-break.
Pictures 6 & 7   cutback 1 & 3 months post cutback (Barbara Hilton)
Defra s Pesticide Safety Directorate has given off-label approval for herbicides
used for cereals, grass and maize to be used on SRC. Visit:
http://www.pesticides.gov.uk/. Since there are no label recommendations, all
products are used at the users own risk. Users should ensure compliance with
instructions on the product label and the Code of Practice for using Plant
Protection Products (http://www.pesticides.gov.uk/safe_use.asp?id=64)
5  20 shoots will emerge from each cutback stool depending on the variety.
Within 3 months of cutback, canopy closure will have occurred providing
natural weed control due to reduced light at ground level.
Headlands and rides
Headlands and rides should be allowed to naturally regenerate or sown with
species-rich fine grass mixes and cut once a year. This regime provides some
support for vehicle movements at harvest whilst also encouraging the
establishment of beneficial flora.
Fertilisation
Digested, i.e. treated, sewage sludge can be applied to SRC as a fertiliser if it
is considered feasible by the local Water Company under UK sludge
regulations and their own guidelines. Accurate nutrient requirements of the
crop are still under research but where treated sewage sludge has been
applied the subjective view of growers is that it is beneficial. Under the
Protection of waters against pollution from agriculture (currently under
consultation www.defra.gov.uk/corporate/consult/waterpollution-
nitrates/consultation.pdf), no more than 250kg organic nitrogen/ha/year can
be applied to agricultural land. SRC has a low demand for nitrogen (N) and
under UK growing conditions, N fertiliser is not usually applied during or after
establishment i.e. from planting until after the post-cutback herbicide
application has had time to be effective.
Due to the growth form of SRC and the equipment currently available,
fertiliser application can be difficult in year 2 of the harvest cycle and
impossible in year 3. Opportunities to work over the crop usually have to be
taken in year 1 after cutback and, where possible, in year 2. However, treated
sewage sludge in liquid form can be applied using a dribble bar fed by an
umbilical system. This allows the sludge to be applied directly to the ground
surface through a series of pipes fed from the dribble bar with no
contamination to the crop and it can be used on coppice up to 2.5m in height.
The use of composted sewage sludge applied using standard agricultural
spreaders is being investigated to assess the benefits of applying up to 3
times the annual limit of total N, i.e. 700-750kg N/ha, in 1 application. Once
SRC has an established root system, the uptake capacity is well above 100kg
N/ha and between 100 and 185kg N/ha is taken up without leaching. The
potential of composted sludge is that it could be applied after cutback and
again after harvest when there are few practical difficulties with working over
the crop, although the height of the stems must be less than 50cm. Only
5-10% of the nitrogen would be released per year, i.e. during the growing
season when temperatures rise the composted sludge would provide up to
70kg N/ha/yr for each year of the 3-year harvest cycle. The remaining
nitrogen is held within the organic component of the compost and is not
leached out.
It should be noted that different varieties of SRC willow and poplar show wide
genetic variation for nutrient-use and water efficiency and will perform
differently in different environments. This needs to be taken into account when
assessing need for and levels of nitrogen application.
Nitrate Vulnerable Zones
Although from research to date SRC will prove to be a beneficial crop for
planting within Nitrate Vulnerable Zones (Goodlass et al. 2004), it is essential
that all Defra regulations relating to these zones are complied with.
A mature SRC plantation, i.e. after establishment, will have a dense,
widespread root system and this, combined with a long growing season,
enables the crop to efficiently utilise nutrients. Research, in the UK and areas
of Scandinavia with similar growing conditions, has shown that the uptake of
available nitrogen by SRC is very effective and, consequently, nitrate leaching
is much lower than that from fertilised grassland or arable land. Also with SRC
there is no soil disturbance to promote mineralisation.
Nitrate leaching has been recorded in the following situations:
" after green cover removal in the land preparation phase,
" during the establishment year where nitrogen has been applied as fertiliser,
and
" after final removal of the crop.
It is therefore important that no fertiliser is applied during the establishment
year, i.e. after planting and before cutback The root system will not have fully
developed and would not be able to utilise the additional nutrients.
Pests and diseases
Rust is the most important disease of SRC, caused by a number of species of
fungi called Melampsora. Rusts can infect both willow and poplar and, when
severe, can lead to crop failure. The most important way of controlling rust is
to plant a mixture of resistant varieties. Willow and poplar are highly diverse
and there is a large gene pool for rust resistance. Over the years, plant
breeding programmes have been successful in producing high-yielding SRC
varieties that are resistant to rust.
Picture 8 & 9  Ming Pei s leaf & Marian s willow afflicted with rust
Monocultures of SRC, i.e. block planting of single varieties, can be highly
vulnerable to rust damage, as the pathogen can adapt to changing
circumstances and breakdown host resistance. Research findings in the UK
suggest that planting host genotype mixtures can be highly effective in
reducing rust impact and sustaining biomass yield. It is recommended that at
least 6 different varieties be planted in a random mix at each site. The use of
fungicides is not recommended for economic, practical and environmental
reasons.
Chrysomelids (willow and poplar beetles) are the most important insect pest
of SRC. Their numbers can build up rapidly in spring and, as both adults and
larvae feed on the leaves, they can cause considerable damage to the crop.
For example, removal of 90% of the leaves in summer can reduce the yield by
as much as 40%. Adult beetles overwinter in rotting wood, under the bark of
trees and in similar habitats short distances from the coppice. As
temperatures start to rise in the spring, the adults move into the edge of the
coppice, start feeding, mate and then gradually move further into the crop. If
beetle numbers reach 100 adults or more shaken from the canopy per square
metre of ground surface, then either a local application of an appropriate
insecticide directed specifically to where the beetles are congregating within
the crop or a spray applied from the edges of the coppice if the beetles are
more dispersed, will save the crop from further damage. Overspraying a
mature plantation would prove costly, not only financially but also ecologically
as the insecticides used are not specific to their targets and would therefore
damage many non-target and beneficial insects. Beetle populations tend to
fluctuate between years so a large infestation one year does not necessarily
mean that it will occur again. Planting a mix of varieties is therefore
recommended as the beetles tend to feed preferentially on some varieties
before moving onto others and this slows their spread through the coppice.
Picture 10 & 11 - Willow aphids (Rothamsted)
The Game Conservancy Trust has produced a booklet describing integrated
pest management techniques for SRC (Tucker & Sage, 1999) which includes
sections on willow and poplar beetles and rust.
Browsing animals such as rabbits and deer can also cause damage to mature
SRC but the main risk is during establishment i.e. the first 18 months from
planting.
8. Calendar of activity
The following table provides an indication of the timing of major activities during the first two harvest cycles of a willow SRC
plantation under a 3-year rotation.
Year Period Activity
PREPLANTING
" Consider site selection and liaise with neighbours, local authorities, archaeologists,
-1 Jan - Jun
ecologists etc.
" Prepare evidence of market for SRC
" Prepare and submit Defra ECS Establishment Grant application
Jun-Sep
" 1st application of systemic herbicide
" 1st or 2nd application of systemic herbicide
Oct-Dec
" Incorporate sludge cake if appropriate
" Sub-soiling (if necessary)
" Ploughing
" Ordering cuttings
ESTABLISHMENT
Jan 
" Erect rabbit fencing where necessary
1 Mar
Mar 
" 2nd or 3rd application of systemic herbicide
May
" Power harrowing and planting
" Rolling and application of pre-emergence residual herbicide (together with leatherjacket
control if necessary)
" Monitor for pests and check rabbit fencing
Jun-Dec
" Monitor for pests, maintain rabbit fencing and check overall crop health
" Remedial weed control if required
2 Jan-Feb " Cutback (willow) and gap up as necessary
Feb-Mar
" Application of contact herbicide
Apr-Jun
" Apply liquid sludge/sludge pellets/fertiliser as appropriate
" Monitor for pests and check rabbit fencing
Jun-Dec
" Monitor for pests and diseases and maintain rabbit fencing
3 Mar-Aug
" Apply liquid sludge/sludge pellets/fertiliser if appropriate
" Monitor for pests, particularly willow beetle
4 Mar-Aug
" Apply liquid sludge/sludge pellets/fertiliser if appropriate
" Monitor for pests and diseases, treat as necessary
Oct-Dec
" Agree harvesting dates and delivery schedule with end user
" Harvesting and delivery to end user as fresh material
" Harvesting, storage and drying
5 Jan-Feb
" Harvesting, storage and drying
Feb-Mar
" Apply contact herbicide if necessary
" Apply liquid sludge/sludge pellets/fertiliser as appropriate
" Storage and drying of harvested material
" Delivery of chip to end user
Mar-Aug
" Monitor for pests, particularly willow beetle and spray as necessary
" Summer harvest if site unsuitable for winter harvest
" Storage and drying of harvested material
" Delivery of chip to end user/processor
6 Mar-Aug
" Apply liquid sludge/sludge pellets/fertiliser if appropriate
" Monitor for pests and diseases, treat as necessary
7 Mar-Aug
" Apply liquid sludge/sludge pellets/fertiliser if appropriate
" Monitor for pests and diseases, treat as necessary
" Summer harvest if site unsuitable for winter harvest (not between 1 March and 31 July for
bird protection
Oct-Dec
" Harvesting
9. Harvesting
Harvesting generally takes place on a 3-year cycle, the first harvest being 3
years after cutback. The work is usually carried out during the winter, after
leaf fall and before bud-break, mid-October to early March. No cutting should
take place during the bird nesting season (1 March to 31 July.) The Wildlife
and Countryside Act 1981 prohibits the disturbing or destruction of birds nests
while they are being built or in use. Certain wild birds have additional
protection year-round under the Natural Environment and Rural Communities
Act 2006.
SRC can be harvested as rods, chips and billets (see definitions below). End-
users or processors will generally require the fuel in the form of wood chip, to
a maximum size, so it is important to check your customers requirements
prior to harvesting. SRC can also be sent for pelleting to produce a compact
and convenient fuel for domestic use. Customers may also need the wood
chip dried to a particular moisture content (MC). For example, willow is
generally in the range 45-60% MC at harvest but customers may want a MC
below 30%. The type of harvesting machinery used will depend on the end-
user s requirements. Details of the latest machinery available to buy or hire
can be obtained from the Biomass Energy Centre (see  Contacts section).
Product Definitions
Chips: Cut material, up to 5 x 5 x 5cm in size
Billets: Cut material, 5  15cm long
Rods: Harvested stems up to 8m in length
Picture 12  harvest 4a (Barbara Hilton)
Direct-chip harvesting
Specifically designed SRC headers for direct chipping of the crop are fitted to
forage harvesters: the stems are cut, chipped and then blown into an
accompanying trailer. Storage and drying of the fresh wood chip can cause
problems; stored, fresh wood chip can heat up to 60°C within 24 hours and
start to decompose if not stacked correctly. During decomposition, calorific
value, i.e. the energy value of the fuel, is lost. Also the fungal and bacterial
spores produced during decomposition constitute a health hazard. As the fuel
will be needed all year, storage, drying and prevention of decomposition must
be considered. The use of grain driers, ventilated-floor-driers and low-rate
aeration using ducts have all been investigated (Garstang et al, 2002). It is
currently considered uneconomic to dry wood chip by any method other than
natural air-drying, where the moisture content will normally go down from 50%
to 30/35% within a few months, unless the end-users require a moisture
content of 30% or less. It is important to ensure that the energy used in
producing wood chip for fuel is kept to a minimum.
Picture 13  building chip pile (Barbara Hilton)
Billet harvesting
Intermediate between rod and direct chip harvesting is billet harvesting. The
stems are cut whole, cut further into billets and blown into an accompanying
trailer. Due to the spaces between the billets, natural ventilation occurs within
storage piles preventing the difficulties associated with chip storage. However,
depending on the fuel specification of the end-user, the billets may need to be
chipped prior to use.
Rod harvesting
Rod harvesting is currently not in commercial practice in England. Harvesters
cut loose rods which need to be off-loaded into heaps on the headlands or on
farm. There is some wastage with this method as rods are left in the field and
after collection from headlands. However, loose rods do dry by natural
convection and do not deteriorate with time.  Bundler harvesters cut whole
stems, bind them and then cut them into bundles 2.5m long. The bundles can
be stacked on headlands or on farm and can dry down to approximately 30%
MC in 3-4 months. Chipping of dried whole rods or bundles tends to result in
shattering of the material rather than chipping; therefore, where chip size and
quality are important, chipping fresh material is recommended.
10. Yield
SRC yields will vary according to the location of the site and the efficiency of
land preparation. Soil type, water availability and maintaining soil moisture,
general husbandry, and pest and weed control will also affect yield. Yield
following the first harvest of a number of commercial sites was in the range
7-9 odt/ha/yr. Yields should also increase at second and third harvests up to
15 odt/ha/yr on better sites. Breeding programmes continue to produce
varieties that out-perform older varieties. Poplar coppice stools tend to
produce fewer heavier stems compared to willow resulting in lower annual
yield increments in the first 2 years but larger increments in years 3 and 4.
Poplar can produce yields that are comparable with willow on suitable sites.
11. Removal of SRC
After the final winter harvest, the stools should be left and allowed to shoot the
following spring. When shoots of more than 15cm in height have developed,
the entire coppice should be over-sprayed with a systemic contact herbicide
to kill the willow. Running either a sub-soiler or a large diameter disc along the
rows close to the stools will sever the main structural roots, which run
horizontally from the stools. When the shoots have died back, the stools
themselves can be mulched by use of a bush-hogger (heavy-duty grass-
topper or pulveriser) into the top 5-10cm of soil. The field can then be grassed
for the first year following removal and (if appropriate) used for standard
arable cropping the following year. Using this method, final harvest to re-
seeding, will take 18-24 months.
To shorten the process, the final harvest can be taken in late summer/early
autumn and the stools again allowed to shoot. When the shoots are 15cm or
more in height, the herbicide should be applied, the structural roots cut and,
following death of the shoots, the stools mulched. Depending on soil type, the
stools can be ploughed in prior to winter. This will allow an early re-seeding
the following spring.
12 Carbon savings
As they photosynthesize, energy crops capture CO from the atmosphere,
2
storing carbon in their stems, roots and leaves and returning oxygen to the
environment. This stored carbon is released back to the atmosphere when the
biomass is used to produce heat and/or power. Managed sensitively, only
small amounts of fossil fuel derived CO are emitted to the atmosphere during
2
ground preparation, harvesting and haulage operations associated with the
crop. As a result, using SRC to displace fuels such as oil, gas and coal can
bring about significant carbon savings. Care should be taken to maintain
those savings as far as possible by minimising energy inputs to the
processing and transportation of the SRC.
13. Energy Value
SRC has a net calorific value, on a dry basis, of 17 to 18 MJ/kg. The energy
value of 20t of dry SRC would be equivalent to that of 8t of coal. Growing
SRC as a fuel is very energy efficient, with a high energy and carbon balance
(outputs:inputs of up to 30:1 is claimed).
SRC can be used for a range of end-uses - from co-firing in coal power
stations, to large-scale electricity power stations and for small scale heat
production. Potentially, it could also be used as a feedstock for second-
generation biofuel processes if these are developed. Information on the full
range of biomass derived fuels and associated conversion technologies is
available from the Biomass Energy Centre www.biomassenergycentre.org.uk.
14. Further Environmental considerations
Biodiversity
Despite the fact that it is essential to maintain low densities of weeds during
the establishment of SRC, once the crop is mature the growth of a ground
flora is beneficial. Ground cover encourages the presence of some
invertebrates, which in turn leads to an increase in the number of small
mammals and birds found (Cunningham et al, 2004 & 2006). High numbers of
bird species are also found throughout the year and over the 3-year harvest
cycle. Species of high conservation value such as reed bunting and song
thrush have been noted to regularly hold territories in SRC during the
breeding season although there is little data on breeding success. Rotational
harvesting, i.e. maintaining several different age classes within one area of
coppice, provides the optimum sustained habitat. However, large continuous
plantings of SRC that reduce the mix of previous land-uses will quickly reduce
the biodiversity benefits. Hence current best practice if planting large areas of
energy crops, is to plant a patchwork of fields interspersed with conventional
arable or grass crops.
Picture 14  two plots (Rothamsted)
Headlands and rides provide further habitat opportunities for a wide range of
plants and animals, for example, 14 species of butterfly have been recorded
on SRC headlands. Many of the species that use the habitats associated with
SRC (i.e. hedges, scrub and woodland) will predate pest species. For
example, one of the birds commonly associated with SRC, the willow warbler,
is one of the most important consumers of defoliating invertebrates.
Therefore, any management practice that enhances the conservation
potential of the crop is likely to prove valuable for pest management.
15. Other species for SRC
Why grow broadleaved coppice instead of SRC willow/poplar for
energy?
Before the Industrial Revolution, and the consequent use of coal, gas, oil and
electricity for heating and power, wood based fuel was the main way in which
our forbears heated their dwellings and cooked their food. The decline in the
use of such fuels over the last two hundred years is, at least in part, a
reflection of the declining forest area of the British Isles and the availability of
cheap alternative fuels and timber supplied from abroad. By contrast, the use
of wood for energy has been maintained in many countries of central and
northern Europe where wood using industries have been a more consistent
component of the rural economy. Thus, investing in broadleaved energy crops
can be seen as a return to more traditional and sustainable forms of land use.
General background to the management of traditional coppice woodlands can
be found in Harmer and Howe (2003).
That said, the productivity of the other broadleaved species considered in this
guidance will be appreciably less than can be obtained with the willow and
poplar cultivars now widely used for SRC. Therefore their planting is likely to
often be as part of a wider SRC scheme where these species can be used to
provide habitat continuity, possibly by linking other areas of woodland to
create a network in the wider landscape. They may also be used if some of
the area identified for SRC has pockets of poorer soils or corners that are
awkward for machine working. Lastly, some people may wish to create new
areas of broadleaved coppice woodland to provide sources of wood fuel for a
rural enterprise, possibly as small logs to be used in modern efficient
woodburning stoves.
The species
A number of broadleaved species are covered by this guidance, namely:
" Common or black alder (Alnus glutinosa)
" Silver birch (Betula pendula)
" Hazel (Corylus avellana)
" Ash (Fraxinus excelsior)
" Small-leaved lime (Tilia cordata)
" Sweet chestnut (Castanea sativa)
" Sycamore (Acer pseudoplatanus)
All are native species to Britain except for sweet chestnut which was
introduced in the Roman era and sycamore which was introduced in the
Middle Ages. These species provide the framework for most of the
broadleaved woodlands that were the natural cover of much of lowland Britain
(Rackham, 1990). Because these trees are mostly native to Britain, they
provide a natural habitat for many species of wildlife including some that are
suffering because of intensification of land use over the last 50 years. Some
general notes on each of these species are given below.
A point to note is that all the species listed above are normally grown from
seed and there is a much wider genetic variation contained within the planting
material than in the clonal varieties of willow and poplar which are the basis of
SRC. Furthermore, at the present time, there is no genetically improved
material available for any of these species so that plantings are, in some
sense, recreating wild populations of trees. Also, that it is often recommended
to use trees that are grown from seed obtained from sources close to the
locality which should be adapted to the local climate (Herbert et al, 1999).
Species Characteristics Soil preference
(with estimated
yields)
Common alder Found widely on stream Tolerant of wide range of
(3-5 odt/ha/yr) sides and on poorly drained soils, preferably moist ones
areas. A tree that can grow with a pH of more than 6. It
up to 30m tall but coppices should not be used on acid
well and grows rapidly when peats or badly aerated soils.
it is young. Can fix nitrogen If this species (or other
through association with the alders  see below) is being
micro-organism Frankia planted to improve soil
which forms nodules on the fertility, then planting stock
root systems. This means should be carefully
that the species is often inspected to ensure that the
used on degraded or roots show good nodule
impoverished soils to development.
improve fertility.
Silver birch A rapidly growing pioneer Well suited to more acid
(2-4 odt/ha/yr) species which can grow into soils that are often dry and
a tree 25m or more tall. It is sandy. On wetter soils, the
a less reliable coppicing closely related downy birch
species than most of the (Betula pubescens) may be
others listed in this table. If more suitable, but this tends
it is grown for coppice, it is to be slower growing than
important that the stools are silver birch.
cut close to the ground.
Coppice stools tend to be
relatively short-lived.
Hazel Normally found as a shrub A wide range of fertile soils,
(1-2 odt/ha/yr) species in the understorey but best where there is
of native broadleaved some moisture e.g. clay-
woodland. Coppices reliably loams. Not as productive on
and stools can survive for acid and dry soils.
several centuries. Tends to
produce a number of small
diameter stems which may
not be easy to harvest.
Ash A fast growing tree which A species that is site
(3-6 odt/ha/yr) can exceed 35m in height. demanding, growing best on
Coppices well and the moist deep fertile loams,
stools are often long lived. and some lime in the soils.
The whitewood produced is Does not grow well on drier
a favoured firewood, in part soils.
because of the relatively low
levels of moisture in fresh
felled wood.
Small-leaved A tree that can grow to over Suited to most fertile soils
lime 25m tall. Coppices well and from sandy loams through
(2-4 odt/ha/yr) the stool can persist for to clay loams, but is not
many years. It was never a suited to very moist or
favoured coppice species, shallow, dry soils.
in part because of the poor
quality of the firewood.
Sweet chestnut A tree that grows to 30m or Prefers deep acid sandy
(3-6 odt/ha/yr) more. An excellent loams with good drainage,
coppicing species which is and is not suited to poorly
found particularly in south- drained or calcareous soils.
eastern Britain. Smaller
sizes of timber can also be
used to make cleft chestnut
paling.
Sycamore A tall tree reaching over Suited to a wide range of
(3-6 odt/ha/yr) 35m tall on suitable sites. fertile and deep soils, but
Coppices well but stools are growth is poorer on acid or
often quite short lived. poorly drained soils.
Should not be planted close Tolerates exposure better
to native broadleaved than any of the other
woodland of high species on this list.
conservation value in case
the regeneration colonises
the understorey. Often
damaged by grey squirrels.
This guidance is a distillation of more detailed information that can be
found in a number of texts. For more specific guidance consult, amongst
others, Harmer and Howe (2003), Savill (1991), Rodwell and Patterson
(1994) and the interactive information available provided through the
Ecological Site Classification Decision Support Systems
(http://www.forestry.gov.uk/fr/infd-5v8jdg)  see also Pyatt et al. (2001).
For further details of the establishment and culture of these other species,
please see the detailed guidance provided on the Biomass Energy Centre
website www.biomassenergycentre.org.uk.
The estimates of yields are based on experience gained from discussions
with practitioners and other reports in the literature, but readers should be
aware that there is a lack of comprehensive experimental trials with
growing these species on coppice regimes and so these estimates should
be treated with caution.
If the soil is impoverished, and the use of alder species is desirable to
improve growth, then there are three other non-native alder species which
could be considered, namely grey alder (Alnus incana), Italian alder (Alnus
cordata) and red alder (Alnus rubra), all of which have been widely used
on reclamation schemes. These have similar or slightly greater
productivity than common alder. Grey alder and Italian alder are better
suited to drier soils and Italian alder will also tolerate calcareous soils: red
alder performs best on alluvial or moist clay-loams.
16. Abbreviations
BERR Business, Enterprise and Regulatory Reform (formerly
the DTI)
CHP Combined heat and power
Defra Department for Environment Food and Rural Affairs
ECS Energy Crop Scheme
ha Hectare
kg Kilogram
MC Moisture content
MJ Mega-joule (one thousand joules)
MW Mega-watt
MWe Mega-watt electrical capacity
odt Oven dry tonne
RDPE Rural Development Programme for England
17. References
Bell S, McIntosh E 2001. Short Rotation Coppice in the Landscape. Forestry
Commission Guideline Note 2. Forestry Commission, Edinburgh
Crow P, Houston TJ, 2004. The influence of soil and coppice cycle on the
rooting habit of short rotation poplar and willow coppice. Biomass and
Bioenergy, 26, 497-505
Forest Reproductive Material (Great Britain) Regulations 2002. HMSO 3026
www.opsi.gov.uk/si/si2002/20023026.htm
Forestry Commission (2007) Forest Reproductive Material - regulations
controlling seed, cuttings & planting stock for forestry in Great Britain. Forestry
Commission, Edinburgh. www.forestry.gov.uk/PDF/fcfc003.pdf/
$FILE/fcfc003.pdf
Garstang J, Weekes A, Poulter R, Bartlett D, 2002. Identification and
characterisation of f actors affecting losses in the large-scale, non-ventilated
bulk storage of wood chips and development of best storage practices. URN
02/1535 www.berr.gov.uk/files/file14947.pdf
Goodlass G, Green M, Hilton BS, McDonough S, 2007. Nitrate leaching from
short rotation coppice. Soil use and management, 23, 178-184
Harmer R, Howe J. 2003. The silviculture and management of coppiced
woodlands. Forestry Commission, Edinburgh.
Herbert R, Samuel S, Patterson GS 1999. Using local stock for planting
native trees and shrubs. Forestry Commission Practice Note 8, Forestry
Commission, Edinburgh.
Johnson P 1999. Fertiliser requirements for short rotation coppice. ETSU
report B/W2/00579/REP/1
McKillop IG, Dendy JA 2000. Advice on rabbit management for growers of
short rotation willow coppice. BERR publications URN 00/1609
Pyatt DG, Ray D, Fletcher J 2001. An ecological site classification for forestry
in Great Britain. Forestry Commission Bulletin 124, Forestry commission,
Edinburgh.
Rackham O 1990. Trees and woodlands in the British landscape. J.M. Dent
and Sons Ltd., London.
Rodwell J, Patterson GS 1994. Creating new native woodlands. Forestry
Commission Bulletin 112, HMSO, London.
Savill PS 1991. The Silviculture of trees used in British Forestry. CABI,
Oxford. 143 pp.
Sludge (Use in Agriculture) Regulations 1989. HMSO (1263)
Sludge (Use in Agriculture) (Amendment) Regulations 1990. HMSO
Tubby I, Armstrong A 2002. The establishment and management of short
rotation coppice  a practitioner s guide. Forestry Commission Practice Note.
Forestry Commission, Edinburgh
Tucker K, Sage R 1999. Integrated pest management in short rotation
coppice  a grower s guide. Game Conservancy Limited, Fordingbridge,
Hampshire
Cunningham MD, Bishop JD, Watola, G, McKay, MV, Sage RB (2006) The
effects on flora and fauna of converting grassland to SRC. DTI report URN
06/1094
Cunningham MD Bishop JD, McKay, MV, Sage RB (2004) ARBRE monitoring
 ecology of SRC. DTI report URN 04/961
18. Contacts
For more information on the Energy Crops Scheme, visit the Natural England
internet site www.naturalengland.org.uk/
For more information on policy developments on energy crops and industrial
crops contact:
DEFRA
Crops for Energy Branch
Area 5a
Ergon House
Horseferry Road
London SW1P 3JR
Tel [phone]
Visit www.defra.gov.uk/erdp/schemes/energy for information on the Energy
Crops Scheme.
" The DEFRA Code of Good Agricultural Practice for the Protection of
Water, Soil and Air Quality (currently being updated)
www.defra.gov.uk /corporate/consult/cogap-rev/index.htm
" Controlling Soil Erosion
www.defra.gov.uk/environment/land/soil/pdf/soilerosion-
combinedleaflets.pdf
" Nitrate Vulnerable Zone Regulations
www.defra.gov.uk/environment/water/quality/nitrate
" Cross Compliance Guidance Handbook
www.rpa.gov.uk/rpa/index.nsf/0/edd25767705ebd0b802570d1005898b
4/$FILE/XC%20Handbook.pdf
" SPS Soil Protection Review
www.rpa.gov.uk
" UK Biomass Strategy
www.defra.gov.uk/environment/climatechange/uk/energy/renewablefue
l/pdf/ukbiomassstrategy-0507.pdf
" SRC opportunity maps
www.defra.gov.uk/farm/crops/industrial/energy/opportunities/index.htm
" Biomass Energy and historic environment
www.helm.org.uk/upload/pdf/Biomass-Energy.pdf
" Bioenergy:Environmental Impact and Best Practice
www.wcl.org.uk
" Protection of waters against pollution from agriculture (currently under
consultation)
www.defra.gov.uk/corporate/consult/waterpollution-
nitrates/consultation.pdf
Contacts for advice, planting material and equipment
" ADAS Renewable Energy www.adas.co.uk
" Biomass Energy Centre
www.biomassenergycentre.org.uk
" Business, Enterprise and Regulatory Reform (BERR):
www.dti.gov.uk/energy/sources/renewables/index.html
" Bioenergy West Midlands www.bioenergywm.co.uk/
" Bio Energy Group East Midlands www.bioenergygroup.org/
" ESD Biomass www.esdbiomass.co.uk
" Game Conservancy Trust: www.gct.org.uk/
" John Amos & Co www.johnamos.co.uk
" Renewable Fuels Ltd www.renewablefuels.co.uk/
" National Non Food Crops Centre www.nnfcc.co.uk
" RegenSW www.regensw.co.uk/
" Renewables East: www.renewableseast.org.uk
" Renewable Energy Association www.r-p-a.org.uk
" Renewable Energy from Agriculture www.refa.org.uk
" Renewable Energy Growers www.energycrop.co.uk
" Rothamsted Research www.rothamsted.ac.uk
" RSPB www.rspb.org.uk
" Strawsons energy www.strawsonsenergy.co.uk
" The Carbon Trust: www.thecarbontrust.co.uk
" TV Bioenergy www.tvbioenergy.co.uk