GET SOIL CONDITION RIGHT IF YOU WANT TO GET THE MOST OUT OF NO TILL10 January 2017
Managing the transition from traditional cultivations to a no tillage approach can have a critical effect on the success of the system, visitors to a ProCam Prochem soil conference have been told. Taking time to correct soil problems such as compaction and poor drainage beforehand could have a profound effect on future cost savings and yields, ProCam technical director Dr. Tudor Dawkins told the audience.
“Growers changing to no tillage typically experience a yield loss but there is a lot that can be done to reduce this with much of it revolving around soil management.
“The better the condition of the soil before you start, the lower the initial yield reduction will be and the more likely this will improve as the system beds in over subsequent years.”
Drainage was one of the first issues that should be looked at, he pointed out.
“Black grass survives very well in wet conditions and it takes a huge amount of energy to raise the temperature of wet soil in the spring so crops can start growing.
“Anaerobic conditions in wet soils also have a detrimental effect on essential soil bacteria and microflora.
“So, check the drains, repair them where necessary and make sure water drains from the profile. Mole draining can be useful if your soil has a good stable sub-surface to hold the mole.”
Since 2012 there had been a lot of problems particularly with soil ‘slumping’ due to the wet conditions and sub-surface compaction, he added.
“Compaction has a big effect on root development and yields with considerable differences between crops. Legumes are very sensitive to poor soil structure whereas cereals are generally more tolerant.
“Just a single trailer wheeling at harvest, particularly when conditions are wet, can cause significant sub-surface compaction which has a major effect on water infiltration rates.
“A good soil has plenty of roots and active bacteria and a sound practical assessment of overall soil health can be made simply by counting the number of earthworms present.
“If you want to get serious you can use a penetrometer to establish where impeding layers exist in the profile or use more specialist techniques to work out the bulk density of your soil.”
Taking care over cultivations designed to break up compaction layers was critically important, Dr. Dawkins said.
“Varying plough depth is a good way of avoiding formation of pans but where any do exist you must work below this level to break them up.
“The better the soil structure before you start, the greater the chances of success with no tillage subsequently. But don’t throw away the plough, you will need it occasionally.”
Professor Dick Godwin of Harper Adams University said those growers that had tried a no tillage approach in the past and had experienced disappointing yield results in wetter areas with less structured soils should probably reconsider the situation – particularly with regard to the overall economic, labour and environmental benefits.
“The biggest thing that has changed in recent years is the quality of the equipment now available.
“The typical yield loss seen by growers switching to no tillage is around 1.0t/ha but the gap should narrow as the years goes by as it does take time for soil to recover from an intensive system.”
Andrew Mahon of Bromborough Estates in Northamptonshire told delegates that careful management of the changeover to no tillage for their 1000ha of combinable crops kept the yield drop for wheat to less than 0.3t/ha with high quality cover crops playing a valuable role in achieving this.
“Harvest 2012 was the turning point for me. We experienced 30% drop-off in yield, quality was horrendous and we simply couldn’t harvest some fields.
‘I knew something had to change and in 2013 we planted our first cover crops straight after harvest and invested in a Mzuri drill. In 2014 we a second hand bio drill and Carrier to establish cover crops and have just bought a 5.0m cross slot no till drill .”
Less time cultivating, reduced overall costs, better soil condition and improved crop establishment are key benefits of the no tillage approach, he said.
“The Mzuri drill moves a lot of soil and whist we didn’t see any drop off in yield, we did get a flush of black grass from the soil disturbance which is why we have now moved on from this.
“Even though we’re now fully no tillage, when I look at 3 and 5 year average yields I would say we’re between nought and 0.3t/ha down on where we were and the cost savings far outweigh this.”
Much of this is due to strategic use of cover crops with DSV TerraLife mixes and their wide variety of different rooting depths playing a leading role in soil conditioning.
“Compaction and poorly drained soils are the biggest enemies of no till systems, but I can honestly say it’s something we just don’t have a problem with.
“We’re real advocates of using roots not iron to break up soil – even our very heavy clay soils fall apart now and there are visibly more worms and more roots.”
If you go too cheap with mixes and they just won’t do the job you want them to, he pointed out.
“We try and spend around £35/ha on cover crops which is roughly the same cost as a cultivation pass but the results are much better.”