Article taken from Crop Production Magazine
Hand in hand with making sure tyres are running at the correct pressure and that tractors are balanced, there are some essential steps growers can take to improve the health of their soils, reckons Chris Martin of Agrovista. “A soil that’s in good heart is more resilient to compaction and gives you a wider cultivation window,” he points out.
Less is more
Keeping field traffic to a minimum, especially in the out of crop periods, is one of the surest ways to minimise compaction. “No matter how low your tyre pressure, a pass with a machine will always compact the soil. In controlled traffic farming (CTF) systems you can limit the area of a field travelled to just 20%. CTF doesn’t suit everyone, but there’s a lot you can do to limit field work.”
One of the biggest culprits is baling the straw, he says. “Not only does this mean multiple passes, but these are carried out by contractors often operating on high pressure tyres. Question whether it’s worth baling, and if you need the straw, consider buying it in,” advises Chris Martin.
Move away from rotary
A soil with a healthy organic matter (SOM) content maintains its structure and is more resilient to compaction weather extremes, he explains. “But SOM in arable soils has been in decline for decades – we’ve been mining them for too long. If we want to take yields to the next level, we have to build SOM, and you can’t do that if you beat soils into submission.”
Here he singles out the power harrow as the biggest culprits. “It’s a victim of its own success because you can’t force a seedbed when you shouldn’t really be on the soil at all. So it delivers a double whammy in terms of damage – it’ll knock structure out of vulnerable soils and increase the rate of SOM loss. It’s also the worse implement possible for earthworms.” But growers don’t need an onion standard seedbed, he stresses. “Modern drills can place seed very accurately and achieve excellent seed to soil contact without much surface disturbance.”
Subsoil sensibly
There’s a place for the subsoiler, says Chris Martin, and that’s directly beneath the compaction layer. But there’s only one way to find where that is.
“Get a spade and dig a few holes. Check first that you need to subsoil at all, and then gauge at what depth this should be. There’s a misconception and that the name ‘subsoiler’ means it has to work deep, but the correct depth is often shallower than you think.”
Go too deep and you can actually create a compacted layer, he warns. “You’ll also use more fuel than necessary and increase wheel slippage and surface compaction.”
Build biota
There’s growing evidence that cover crops build SOM, structure, resilience and can even replace a cultivation pass, says Chris Martin. “Harness the sunlight in the post harvest period to grow a crop that will your soil some good and bring it back to life – sun powered roots must be better for soils than iron.”
The prolific roots of crops such as black oats not only provide structure, they feed the soil and the biota that lives in. “Berseem clover – known as the jackhammer – has a more pivotal root structure and tends to grow through compacted layers that oilseed rape roots will avoid. This makes it a good companion planet for OSR,” he notes.
“For best effect, cover crops should be established no later than mid Sept, with a view to following with a spring sown crop. You can count some seed mixes (such as vetch and black oats but not berseem clover) towards your ecological focus area,” he add
Hand in hand with making sure tyres are running at the correct pressure and that tractors are balanced, there are some essential steps growers can take to improve the health of their soils, reckons Chris Martin of Agrovista. “A soil that’s in good heart is more resilient to compaction and gives you a wider cultivation window,” he points out.
Less is more
Keeping field traffic to a minimum, especially in the out of crop periods, is one of the surest ways to minimise compaction. “No matter how low your tyre pressure, a pass with a machine will always compact the soil. In controlled traffic farming (CTF) systems you can limit the area of a field travelled to just 20%. CTF doesn’t suit everyone, but there’s a lot you can do to limit field work.”
One of the biggest culprits is baling the straw, he says. “Not only does this mean multiple passes, but these are carried out by contractors often operating on high pressure tyres. Question whether it’s worth baling, and if you need the straw, consider buying it in,” advises Chris Martin.
Move away from rotary
A soil with a healthy organic matter (SOM) content maintains its structure and is more resilient to compaction weather extremes, he explains. “But SOM in arable soils has been in decline for decades – we’ve been mining them for too long. If we want to take yields to the next level, we have to build SOM, and you can’t do that if you beat soils into submission.”
Here he singles out the power harrow as the biggest culprits. “It’s a victim of its own success because you can’t force a seedbed when you shouldn’t really be on the soil at all. So it delivers a double whammy in terms of damage – it’ll knock structure out of vulnerable soils and increase the rate of SOM loss. It’s also the worse implement possible for earthworms.” But growers don’t need an onion standard seedbed, he stresses. “Modern drills can place seed very accurately and achieve excellent seed to soil contact without much surface disturbance.”
Subsoil sensibly
There’s a place for the subsoiler, says Chris Martin, and that’s directly beneath the compaction layer. But there’s only one way to find where that is.
“Get a spade and dig a few holes. Check first that you need to subsoil at all, and then gauge at what depth this should be. There’s a misconception and that the name ‘subsoiler’ means it has to work deep, but the correct depth is often shallower than you think.”
Go too deep and you can actually create a compacted layer, he warns. “You’ll also use more fuel than necessary and increase wheel slippage and surface compaction.”
Build biota
There’s growing evidence that cover crops build SOM, structure, resilience and can even replace a cultivation pass, says Chris Martin. “Harness the sunlight in the post harvest period to grow a crop that will your soil some good and bring it back to life – sun powered roots must be better for soils than iron.”
The prolific roots of crops such as black oats not only provide structure, they feed the soil and the biota that lives in. “Berseem clover – known as the jackhammer – has a more pivotal root structure and tends to grow through compacted layers that oilseed rape roots will avoid. This makes it a good companion planet for OSR,” he notes.
“For best effect, cover crops should be established no later than mid Sept, with a view to following with a spring sown crop. You can count some seed mixes (such as vetch and black oats but not berseem clover) towards your ecological focus area,” he add