August 1, 2014
Soil-centred OSR improvement on show
Simon Collins and his team at the Giffard family’s Chillington Estate near Codsall have made great progress in overcoming a number of typically West Midlands mixed farming barriers to oilseed rape production over the past six years.
By focussing their improvement attention firmly on crop establishment through better soil management, timeliness and precision, they are well on their way to pushing yields across their 120 acres of winter OSR from an historic 1 t/acre or less to 1.5 tonnes and beyond. And, most importantly, to doing this on a consistent, whole farm, over-the-weighbridge basis.
As visitors to the special Agrii OSR Establishment Demonstration Day the Estate is hosting this August will discover, farm manager, Simon and his agronomist, Peter Jones have a whole host of further improvements in mind over the next few years to build on their achievements to date.
“What we need more than anything else is a fast establishment system that combines the sub-soiling we insist upon before rape with sort of quality seedbeds we currently rely on our plough and power harrow/drill combination to deliver,” Simon explained.
“We need to get our oilseed rape off to the best possible start to give it enough of an edge over the game birds and pigeons we have in abundance, courtesy of well over 800 acres of woodland criss-crossing our 1200 acre arable area.”
“But this has always been challenging. The rape has to go in after wheat in our four year arable rotation as we need the barley ground to grow stubble turnips for our 1500-ewe lamb enterprise. Add to this the fact that all our straw is baled, so we can never drill as early as we’d like. Our largest field is 28 acres, which means we can’t drill nearly as fast as those with wide open arable spaces. And soils varying from pot clay to blow-away sand don’t do us any favours either.
“On our Demo Day we’re really interested to see how a number of different establishment systems cope with the sort of challenges our ground – along with a lot of land in this area – presents this autumn. Certainly, it will be far more revealing that seeing the same equipment at work in East Anglia !”
Central to the winter OSR improvements being made at Chillington is a far better understanding of the estate’s soils, driven by the values and experience – not to mention organic degree – Simon Collins’ gained while managing an organic conversion in the Cotswolds.
Much of the land is decidedly hungry, the estate doesn’t have access to useful supplies of FYM and baling all the straw is a further challenge to organic matter as well as potash levels. However, valuable contributions to fertility come from lambs grazing the 120-140 acres of stubble turnips grown each autumn and winter beans sown after them as the main winter wheat entry.
Perhaps the biggest soil-based obstacle to oilseed rape performance identified by Simon and Peter early on in their improvement efforts – with the help of test pits dug with Agrii oilseed rape specialist, Philip Marr – was serious compaction built-up over the years on the sandy ground, in particular. They overcame this by introducing sub-soiling into the rotation as a routine ahead of every OSR crop, despite the extra time pressures it placed on establishment.
Since then SoilQuest scanning by John Lord and his team has revealed the true extent of the variation in the estate’s glacial deposit soils. Each 20-25 acre field, for instance, typically has four or five different soil types with pHs down to well below 6.0, and TSP recommendations varying from zero to 145 kg/ha. This makes the variable rate P, K and lime applications – which have now also become a matter of course – especially valuable. What’s more, the precision technology is paving the way for variable seed rates. And it offers the opportunity to vary nitrogen applications too.
“Allowing for our challenging soils and the serious winter bird damage we almost always get, we haven’t dared go below 50 seeds/m2 even with the vigorous, fast-developing hybrids, DK ExPower and Excalibur we’ve switched to growing,” explained Peter Jones.
“These are an immense improvement on both the pure lines grown in the past and the hybrid we originally tried for its apparent lack of palatability to pigeons. Now we have the varieties with early get-up-and-go we need, varying their sowing rate to individual management zones should really help us achieve the 20-25 plants/m2 we’re after with far greater consistency and less risk across every part of every field.
Varying the nitrogen we apply – both to the seedbeds in the autumn and in our two spring splits – could also give us useful advantages in securing the even, well-branched canopies we want from our modest 150-160 kg N/ha total, ” he added. “In so many ways, precision agronomy looks like being a real game-changer here.”
Interestingly too, precision agronomy has given the Chillington team a valuable edge in tackling another of their major OSR establishment challenges – poppies.
“Small, awkwardly-shaped fields with a good sprinkling of parkland trees meant we’d never been able to use a pre-em in the past,” pointed out Simon Collins. “Instead, we’d always had to wait until the crop showed us the tramlines before going in with our first spray. “With GPS guidance from our Patchwork box, though, we’re now able to get the pre-em applied just when it needs to be, with no overlaps or misses. So we’re nowhere near as vulnerable to the weather holding-up post-em spraying as we used to be.”
All the ingredients have really come together well with winter rape at Chillington this season. Good, compaction-free seedbeds, precision fertilisation, fast-developing hybrids and very much better early weed control are really proving their worth in allowing the crop to take full advantage of the favourable growing conditions. Add timely nitrogen, trace element, fungicide and PGR use and the result is a robust, pod-filled crop that looks set to break all performance records.
Even so, following particular success with the alternative last season, Simon and Peter have given themselves a valuable extra string their bow by introducing spring rape into the cropping regime – as a permanent fixture for the most difficult fields and a fall-back for any that can’ reasonably be drilled in a difficult autumn. That way they hope they’ll never have to face what used to be the regular task of ripping out winter rape through poor establishment.
“We’re making winter rape establishment so much better and more reliable these days,” concluded Peter Jones. “And with the right one-pass system we’re sure we can improve performance and reduce risk still further. But, should the weather turn against us or we run out of time, we’ll just stop drilling and leave things for the spring rather than muddling-in the crop more in hope than anything else.
“It’s very much a work in progress here. Not least, because the goal posts keep on moving. With the scale of the flea beetle threat posed by the large area of brassicas grown each year in stubble turnips for the sheep and game cover for the shoot, for instance, establishment without neonics promises give us an even greater challenge from this autumn. So, continued improvements in our OSR establishment agronomy will be all the more vital.”