| Arable
Greener for longer is key to yield building
Fine-tuning agronomy to extend green leaf retention at the end of the season is one of the most effective ways of
boosting wheat yields and breaking the yield plateau affecting UK crops.
hat was one of the main
messages from a recent ADASled Yield Enhancement
Network (YEN) event in
Peterborough, where growers,
researchers and industry
sponsors, including leading agronomy firm
Hutchinsons, gathered to examine ways to
enhance wheat yields.
Maximising light, water and nutrient capture
during the summer months is a key way of
narrowing the existing gulf between average
farm yields at around 8t/ha and the “biophysical potential” of wheat, which can be up to
20t/ha on some sites, says ADAS Boxworth’s
Ian Smillie.
“The bio-physical potential tells you what is
theoretically possible, but the focus is what’s
attainable.
“Annual cereal crops by their nature don’t
have the canopy structure to capture all
sunlight available in a season – a typical 11t/ha
crop may only capture 47% of total incident
radiation for example.
“But, establishing slightly larger canopies
early in the season and then keeping them
green for longer could increase interception to
60%. By far the largest proportion of that
T
Agronomic areas to focus on include:
increase comes from 10 days extra greening at
the end of the season,” he explains.
Senescence is partly determined by genetics
of individual varieties, but is also heavily
dependent on water and nitrogen availability,
and on protection from disease, so growers
should find ways of maximising these
throughout the season, but particularly towards
the end, he says.
How this is best achieved on farm is a key
focus of future YEN investigations, but there are
already many things growers can try this
season, says Bob Bulmer from Hutchinsons,
who stresses that every solution must be
tailored to individual situations.
“There are a number of elements that need
to be combined to ensure canopies are
photosynthetically active for longer.
“Good root systems are important for
maximising water and nutrient capture and we
are also investigating the physiological benefits
of SDHI and strobilurin fungicides on canopies
and water use efficiency. The impact of major
and minor nutrients on canopy development is
another area we are studying.”
Dr Bulmer encourages more growers to join
the YEN project, which is now in its fourth year.
He is keen to point out that YEN’s focus is on
identifying ways to maximise the yield potential
of individual sites, rather than simply competing
to produce the highest-yielding crop.
Prof Roger Sylvester-Bradley of ADAS adds:
“Crop productivity has been somewhat lost in
the drive to reduce costs over the past 25
years, but YEN is all about looking at how the
science of yield can be used to develop unique
best practice for every field.
“Focussing on the money and costs means
you often miss ways to enhance yield.”
But he acknowledges the cost-effectiveness
of different measures needs to be factored into
YEN and suggests this could be one project
area to develop in future.
If you are interested in taking part in YEN this
year please go to www.yen.adas.co.uk or
contact Dr Bob Bulmer by emailing:
[email protected].
The YEN project is led by ADAS and
sponsored by Hutchinsons, Adama, AgSpace,
AHDB Cereals & Oilseeds, Bayer, Limagrain,
NIAB-TAG, NRM, NFU, Rothamsted Research,
de Sangosse, Syngenta and Yara.
Fine-tuning agronomy to extend green leaf
retention at the end of the season can
boost wheat yields says Dr Bob Bulmer of
Hutchinsons
• Encourage more root growth and
deeper rooting (ideally down to 2m) to
allow access to more water and nutrients,
particularly in regions prone to drought
stress and early senescence
• Improve soil structure and rooting ability
by:
Reducing compaction (e.g. controlled
traffic farming, minimising travel in wet
conditions)
Minimise cultivations to build natural
structure
Add organic matter (composts, manures,
cover crops) to build soil biology and
improve structure
Encourage vertical biopores (such as
those created by earthworms or FVW&