2 March 2023 - Flipbook - Page 35
NEWS
FARMWEEK
JANUARY 28 2021
Feed trees to
sheep to cut
greenhouse
gases, study
suggests
FODDER: The use of tree fodder as an
alternative source of food during periods of
drought may become increasingly relevant as
the climate changes
I
NTRODUCING tree leaves to a sheep’s diet
could play an important role in reducing
harmful greenhouse gas emissions, suggests
research presented at the Intercropping for
Sustainability conference.
Scientists from the Game & Wildlife
Conservation Trust (GWCT) monitored four
groups of six Abereld x lambs, half of which
were fed around 200g of goat willow leaves
each per day. When their urine patches were
monitored, they found signicant reductions
in both nitrous oxide and carbon dioxide in
those groups which fed on willow leaves.
The work, part-funded by the Woodland
Trust, also found lower emissions of ammonia
from urine patches where lambs were fed
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willow.
While cutting branches to feed to livestock is
labour intensive, a move towards agroforestry
with livestock (also known as silvopasture)
would allow the direct browsing of coppiced
trees if livestock access is managed to ensure
sustainability.
The use of tree fodder as an alternative
source of food during periods of drought
may become increasingly relevant as the
climate changes, but these results suggest
that a supplementary benet of incorporating
willow into grazing ruminant systems may be
a contribution to climate change mitigation, as
well as air quality improvement.
Defra has recently made it clear that
agroforestry is eligible for support through the
Basic Payment Scheme (BPS), including both
silvoarable (trees planted at wide spacings
and intercropped with a cereal or bio-energy
crop) and silvopasture (trees combined with
forage grassland and livestock production).
The Committee on Climate Change estimates
that agroforestry could result in carbon
emissions savings of 5.9 MtCO2e per year by
2050, approximately 13 per cent of the total
current emissions from the agriculture sector.
Professor Chris Stoate undertook the
research and is encouraged by the ndings:
“This study is a novel application of the
specialist expertise and equipment we have at
the Allerton Project and builds on our recent
research on grass and livestock systems. The
results are preliminary, but they provide an
exciting indication that feeding willow leaves
to ruminants may contribute to national
targets for both climate change and air quality.
It certainly warrants further investigation.”
Despite decreasing by 16 per cent since 1990,
farming in the UK contributes 10 per cent of
the country’s emissions. Any ambition to
reach net zero, which the NFU has set as a goal
for 2040, will require novel solutions.
It is estimated that one kilogramme of N2O
warms the atmosphere about 300 times
the amount that one kilogramme of carbon
dioxide does over a 100-year timescale, so
any potential reduction is worth serious
consideration.
The benets to air quality of the apparent
reduction in ammonia is an added bonus.
Livestock grazing of winter cereals
G
RAZING livestock on winter
cereals could help aid soil
biology, allow for earlier
drilling dates, control pests
and diseases and inuence
yield potential, according to recent
results from a trial carried out on a
mixed farming enterprise in Angus.
The project, which looked at
grazing winter cereals with sheep,
started as a Rural Innovation
Support Service (RISS) group,
facilitated by Peter Lindsay and
Zach Riley of SAC Consulting, part
of Scotland’s Rural College (SRUC).
“The project was developed to
gain a better understanding on
whether grazing livestock on winter
cereals could have a detrimental
effect on, for example, disease
control and yield potential,” said Mr
Lindsay.
Trials were carried out by Balgay
Farming Partnership, a partnership
between Iain Graham and Iain
Wilkinson, after the dry spell
during the summer of 2018 severely
reduced grass growth.
Mr Lindsay explained that Balgay
Farm is run as a mixed farming
business with combinable cropping,
beef and sheep. “The impact of
drought on grass growth during
2018 prompted us to look at ways to
utilise arable land to aid livestock
performance, but also help soil
biology.”
The trial consisted of two-hectare
blocks drilled with winter wheat,
winter barley and winter oats.
Each crop block was split down the
middle with an electric fence and
sheep were allowed to graze one
GRAZING: Farmer Iain Wilkinson with lambs grazing this year’s winter
wheat.
half, but not the other.
Mr Wilkinson said that the results
from the trials were very promising
and demonstrated that the grazing
of winter cereals can provide
valuable winter forage for sheep
and also have a benecial impact on
crop yield.
He added: “We introduced sheep to
the crops at the end of October 2018
and they ate the winter barley right
down to the bone before moving
onto the winter wheat and winter
oats. We were concerned we had
been too hard on the winter barley
and it would have a detrimental
impact on the crop.
WHEAT: Lambs on this year’s winter wheat.
“However, come August, when
the crop was combined, the results
for the winter barley, in particular,
proved to be very positive with an
increased yield of around 0.5-0.75
tonnes per hectare on the grazed
strip.”
The results from the trials also
indicated potential benets to soil
structure and giving the scope
to drill winter crops two to three
weeks earlier.
Mr Lindsay, who is also involved
with the Farming for a Better
Climate’s Soil Regeneration Group,
said many farmers on heavier land
in Scotland struggle to get winter
crops drilled on time due to the
short, often wet weather window
experienced between September
and October and that grazing sheep
could allow for an earlier drilling
date to be achievable without
affecting the crop.
“Traditionally, Iain Wilkinson
would begin sowing winter crops
around the rst week of September,
but with the farm situated on very
at, heavy carse clay, the land can
often be affected by heavy rain.
This year we decided to bring the
sowing date forward to 17 August,
with the aim of getting all the crops
in the ground before the weather
broke and not being force to drill
the problem elds last as is usually
FIELD: Iain Wilkinson standing in a field of winter wheat which had been
grazed hard by lambs until it was fairly black looking. The image was taken
one week later having recovered well.
the case.
“Sheep have recently been put
onto this early sown wheat to graze
back the leaves and hold growth
development, whist at the same
time adding some biology to the
eld.”
With no obvious detrimental
effects to crops highlighted during
the RISS project, SRUC has been
awarded additional funding through
a new MIXED EU project, which will
explore different types of mixed
agricultural systems, including resilience to climate change, sustainability, and agroforestry.
Christine Watson, Professor of
Agricultural Systems at SRUC, who
is leading the MIXED project, said:
“We are delighted to receive funding
through the new EU research
project to help continue to research
and develop evidence on the impact
of grazing livestock on winter
cereals. The project is led by Aarhus
University and involves networks
of both organic and conventional
farmers and research institutions
from 10 countries.
“In agriculture, as in so many
other industries, there has been a
tendency to specialise in certain
areas such as crop or livestock
production. However, great advantages might be achieved from
increased collaboration between
farms and less specialisation on
the individual farm, at landscape
level, or in the supply chain. Our
hypothesis is that systems with
mixed production systems are often
both economically efcient and
sustainable in terms of climate and
environment. They are also more
adaptable to change.”
The new project will see trials
carried out on SRUC and other farms
across Scotland and will combine
the evidence and knowledge already
gathered by the RISS project to
look at other key factors, including
drilling dates, timing of grazing,
grazing intensity, and the benets
to soil structure.
Prof Watson concludes: “We are
more and more dependent on
collaboration across systems and
on being resilient to change. We
hope that this project can continue
to develop knowledge exchange
and solutions to help increase
collaboration within the industry
as well as sustainability and
resilience.”