July 9, 2013
Research-led agronomy brings 15T/HA wheat within reach
Commercial winter wheat yields of 15t/ha are well within the grasp of UK growers, visitors to this year’s Agrii wheat technology event near Marlborough were told. But a thoroughly integrated approach with the best research-led agronomy will be essential if they are to be reliably achieved; not least in the face of growing climatic variability and the progressive loss of plant protection chemistry.
Speaking to more than 300 growers viewing the latest AgriiFocus Technology Centre developments on the 18 ha winter cereal trials site, the company’s head of technology and services, Clare Bend said: “From our 2011 trial work we know we can achieve 15t/ha with the right combination of variety, agronomy and conditions here at Aldbourne.
“Our team’s Best of British Wheat 15t/ha Challenge crop on the chalk near Salisbury delivered 12.7t/ha from enhanced agronomy on a far larger scale in last year’s disappointing national harvest; a good 2t/ha more than the standard agronomy regime alongside it.
“What’s more, despite one of the wettest winters and coldest springs on record, the 2013 Challenge crops of up to 50 ha we’re currently growing with customers on a number of southern farms this season have both the ears/metre and grains/ear they need to meet the target. So we just need sufficient grain fill.”
Like last season, Clare Bend fully appreciates the wild card the weather always plays in this and other respects. Especially so with the increasing frequency of intense weather events we seem to be having these days. That’s why Agrii’s on-farm 15t Challenge work is backed by fully replicated trials into the key agronomic building-blocks of performance and how they can best be integrated to minimise agronomic risk.
“More resilient systems are essential if we’re going to produce 15 tonne wheat crops on a consistent basis,” she stressed. “So the focus across our network of R&D sites is on both the individual ingredients of genetics, nutrition, crop protection, soil improvement and rotation and, most importantly, the ways in which they interact with one another. “Amongst other things, our trials are highlighting the dramatic crop performance and margin improvements possible through enhanced fungicide, PGR and crop nutrition regimes on a prescriptive basis. This ensures crops receive the inputs they need at exactly the right time and in the right balance for the particular conditions they face.
“Alongside conventional crop assessments and analyses, we’re exploring exciting new field techniques like chlorophyll fluorescence to measure photosynthetic capacity,” she added. “This offers our agronomists the opportunity to identify and alleviate crop stress before it becomes apparent to the eye and our researchers the opportunity to pinpoint varieties with more tolerance to both disease and environmental stresses for greater resilience.”
Further improvement opportunities highlighted at the event as part of Agrii’s Best of British Wheat efforts include better-planned T(-1) seed treatments, increased crop performance in the first 30 days, alternative fungicide approaches, using protected nitrogen and phosphate, and managing resistant grass weeds.
“Grass weeds are the biggest single threat UK wheat production faces today,” pointed out Clare Bend. “Growing black-grass resistance and increasingly limited chemistry, indeed, mean we could struggle to grow winter wheat on a good 20% of our current national wheat area unless we apply the most intelligent and integrated solutions.”
Investigating micro-nutritient essentials
Enhanced trace element nutrition delivered an extra 1.05t/ha of wheat in the absence of visible deficiency symptoms in last season’s AgriiFocus systems trials, underlining the value of balanced micro-nutrient applications in improving overall crop productivity.
This uplift came from a combination of zinc, added copper, phosphite and boron in addition to the standard trials programme of manganese, copper and magnesium. And it was associated with a marked increase in the duration of green leaf area. “This year we’re examining which micro-nutrients are having the greatest effect and in what ways,” explained agronomist Andrew Richards in the trial plots. “Guided by last year’s experience and current soil and leaf tissue analyses, we’re looking closely at B, Zn, extra Cu and various combinations of the three in parallel plots of KWS Santiago and Horatio at two nitrogen levels and with both standard and enhanced fungicide regimes
“Despite adequate levels on soil analysis in January, tissue samples in April showed a marked shortage of boron, confirming recent suggestions from our agronomists that this element might be short on chalk soils. It will be very revealing to see what the yields and our detailed crop measurements tell us on this score in particular.”
Soil understanding to the fore
The excessive rainfall of the past year is concentrating growers’ minds on the need to understand their soils in far greater depth, reported Agrii decision support services technical manager, John Lord at one of the event’s specialist mini-seminars.
“The risk we run from too much soil working with too little soil intelligence has become crystal clear in serious problems that will take a lot of overcoming,” he stressed. “As a result, we’ve seen a surge in demand for our SoilQuest precision agronomy service across the country.
“The addition of laser texture analysis in our laboratory soil sampling is proving particularly valuable. It means we can provide precise silt, clay and sand contents for each of the management zones into which our conductivity scanning divides every field.
“With a 5-10% difference in clay content undetectable by conventional hand estimates yet critical to the workability of a soil, this extra precision is really helping growers get the greatest possible value from our detailed soil mapping.”