September 26, 2018
Cultivating Extra Understanding – Revesby Farms Event
Put as much thought into buying and setting-up a £40,000 cultivator as you would a seed drill more than five times its price, growers from across the eastern counties were urged at a recent Lincolnshire cultivations practice day. And do so with an understanding of your subsoil as much as topsoil condition if you want to avoid doing more harm than good with even the shallowest of tillage.
Speaking at the Revesby Farms/Agrii event involving working demonstrations of 18 different cultivators from a dozen leading manufacturers on the Wiggins-Davies family’s Estate near Horncastle, independent soils and tillage specialist, Philip Wright stressed that the sheer range of tine, disc and packer combinations available in today’s kit makes the right choice especially important. Particularly so for those wishing to have the greatest flexibility to deal with both soil and seasonal variations and get the best results from late- autumn sowing to combat black-grass.
“The tilt and spacing of tines and the width and design of their points on the one hand and the type, size, shape, tilt and sweep angles of discs on the other all make a major difference to the extent, type and depth of soil movement,” he pointed out.
“So choosing the best cultivator for your farm and operating it correctly depends on knowing your ground and what it needs each season to set it up for drilling. Otherwise, regardless of the drill you have, you can all too easily make it difficult to get your crops in and away evenly and reliably.”
“There’s absolutely nothing you can do to change the texture of your soil – its balance of sand, silt and clay – and very little short-term effect you can have on its organic matter content,” noted Agrii regional technical adviser, David Felce. “So the whole point of cultivating is to achieve the best balance between the other 50% of your soil that is air and water.
“This is critical for both the establishment of your crops and their resilience in coping with the sort of climatic extremes we seem to be seeing far more of these days.
It’s important to remove any compaction that will impede drainage and rooting, and create a seedbed that makes the most of your drill. In doing this, though, you simply must avoid over-cultivation which is easy to do even with minimal tillage regimes.”
David Felce insisted that all the soil mapping and analysis in the world is only of value if you understand what lies beneath the ground. He illustrated this with SoilQuest laser texturing data from the event field and some of his own arable ground at Midloe Grange Farm near Huntingdon.
Both have quite similar contents of sand, silt and clay at around 25%, 55% and 20% respectively. But while the soil at Revesby sits on chalk, his own is over chalky boulder clay. Which means they behave very differently and have quite different cultivation requirements.
“You need to dig a hole to see exactly what you’re working with,” he insisted. “Digging into this particular Revesby spring oat stubble shows we have a nicely structured soil with no restrictions to rooting right down to the chalk which provides such a good reservoir of moisture. So we only need the bare minimum of surface cultivation, if any, to set it up for the estate’s Horsch Sprinter drill.
“The worst thing we could do here is over-work the ground. It’s lack of clay content means that too much tillage will only serve to increase compaction from traffic and make it more vulnerable to slumping and tightening with rain ahead of the planned late-October-sown wheat. And if the autumn turns really wet this could seriously get in the way of drilling.
“In contrast, we often need to target our cultivations at home on the silt that washes down and builds-up in a layer above our boulder clay to ensure the best drainage and access for rooting.”
Knowing your soils and the sort of cultivation they are likely to need is, of course, only the first step. The critical question is what type of cultivator will do the best job for you? And, equally importantly, what kit will give you the flexibility you need to reliably deal with both the range of soils and conditions you have and the weather variability you will almost certainly get.
“Providing your combine straw chopping and spreading is effective, tine-based equipment is likely to be your first consideration in most cases,” reasoned Philip Wright. “Not least because even shallow-working discs can cause serious problems on soils with a significant clay content if things turn wet.
“Where you wish to incorporate FYM or biosolids or need to deal with significant amounts of above-ground material like volunteers or cover crops which can block tines, though, disc-based cultivators should also be considered.
“Another factor here is the type of drill you have. A disc-based drill can, for example, often be best complemented by tine-based cultivation and vice-versa, rather than both tillage actions being either disc or tine based.”
Alongside the precise type and configuration of tines and discs you have to move the soil, Philip Wright is adamant that the press rollers you use to put it back afterwards are an equally important consideration. As well as good consolidation for the best soil structuring, these need to adequately weatherproof the surface, allowing water to percolate rapidly and evenly across the field; especially where the ground is to be left for an extended period before drilling.
“Overall, I firmly believe you need to put as much thought into your choice of cultivation kit as you would with your very much more expensive drill,” he said. “After all, the success of your establishment depends at least as much on the conditions you are drilling into as the capabilities of your drill.”
Cultivators which can be configured and adjusted as easily as possible to changing soil and weather conditions are of obvious value in Philip Wright’s view. Even so, in most cases, for the greatest flexibility he considers it better to have two different cultivation options available rather than putting all your eggs in a single basket.
As well as a machine that best matches the needs of your ground and system, he suggests having one with complementary capabilities to your existing kit which should then be kept on as a back-up. It may mean having less to invest in the new equipment, he accepts. But it will mean far greater flexibility for the same overall level of cultivator investment.
“Investment in good quality wearing parts is never wasted,” added Philip Wright. “Wear changes the geometry of things like tine angles which significantly alters performance.
“Time setting-up your cultivator is never wasted either. The best way of doing this is to work a small stretch of ground then run a spade across each section of your cultivation to check its depth and consistency. This is something you should do as a matter of course in every field and whenever conditions change.”
Fine-tuning Revesby Cultivations
Six years of consistent soil health and structural improvement at Revesby Estates have enabled manager, Peter Cartwright to progressively reduce the scale and depth of cultivation across the 1220 ha arable business. So much so that a set of points on the primary Horsch Terrano cultivator now does 600 ha rather than the 400ha of the past.
At the same time, he and his Agrii agronomist, Richard Butler are finding increasing areas of the estate requiring little, if any, cultivation. So, as part of their move into a 10m controlled traffic farming system, the estate has invested in a Horsch Sprinter 10W drill with low disturbance coulters and impressive abilities to direct drill or work across a wide range of soil conditions.
“Six years ago I’d have dismissed the idea of CTF here out of hand,” Peter told the growers and agronomists at the event. “But now it’s the logical next step to build-on our soil improvement efforts by minimising trafficking.
“So we’re looking for a 10m cultivator able to work much shallower than the Terrano, setting-up our ground for the pre-planting glyphosate and late-October drilling that’s such an important part of our integrated black-grass management regime.
“Effective re-consolidation of the surface with the best weather-proofing is a key consideration for us, especially on our heavier ground. Getting a good level surface for the Sprinter to drill into without interfering with the soil structure we’ve built-up beneath is also a particular priority.
“Because we’re far from CTF purists, we’ll be keeping-on our 6m Terrano so we continue to have the ability to cultivate at greater depth and more thoroughly wherever and whenever we need to in our rotation. After all, getting the right degree of cultivation has to be our Number One priority.”