Minimal cultivations to stem loss & lift profits
Minimal cultivations to stem loss & lift profits
By Charles Abel
POOR soil management is being blamed for significant environmental damage as up to 2.3m tonnes of soil is lost from farmers fields every year. But minimal cultivations can slash such losses and boost farm profits too.
That is the view of the newly-formed Soil Management Initiative (News, 26 Nov), which aims to promote best cultivations practise, with backing from Monsanto, Simba, ADAS and the Environment Agency and three-year funding from the EU.
A recent MAFF survey suggests 44% of arable land is prone to damage, losing up to 2.3m tonnes of soil per year. That compares with previous estimates that just 9% was at risk, releasing 0.9m tonnes.
"We now know sandy soils on gentle slopes and heavy soils on moderate slopes are at risk as well as sandy soils on moderate and steep slopes," says Tim Harrod of the Soil Survey and Land Research Centre at Cranfield, Beds.
Such losses may not be as intense, but they are much more extensive, he notes. "Significant losses may occur once in five to ten years, rather than every year. But over a period they could average 1t/ha/year."
Falling fish stocks as sediments interfere with breeding, increased pesticide and fertiliser residues in water and cloudy streams which used to run clear can all be attributed to soil losses, says Richard Smith of the Environment Agency. "Join all those together and the problem is worse than was realised before."
Legislation to force better soil management is unlikely, but payments to encourage it may come under stewardship programmes, suggests SMI chairman Dr Andre Carter of ADAS. A greater push is likely to come from food assurance schemes as end users demand best practise, she says. Marks & Spencer is already showing interest.
Ill-timed field traffic and cultivations, plus the use of powered cultivators and excessive cultivation are most likely to cause damage.
Provided the right minimal or no-till systems is adopted and management practices are adjusted accordingly minimum tillage can suit all soil types, says Lower Input Farming and the Environment project manager Vic Jordan of IACR-Long Ashton.
"The key is not just to replace one machine with another, but to rethink the whole system. Youve got to start straight behind the combine, incorporating straw into the top 10cm to start its microbial breakdown and to stimulate weed chit."
The stale seed-bed cuts grassweed problems and drilling at 4cm (1.8in) minimises slug problems, even where trash is a worry, he claims.
Beneficial earthworm numbers rise, soil porosity improves, so reducing run-off, sediment losses fall, phosphate losses drop by almost two thirds and isoproturon losses cease altogether. Nitrogen losses drop significantly as mineralisation caused by ploughing ends.
Alastair Leake, co-ordinator of the CWS/Hydro/Profarma Farming in Focus project agrees. "Farmers need to work the top few inches with skill, not the whole soil profile with horsepower."
• First year results from an HGCA-funded ARC trial near Cirencester gave no statistical difference in yield between no-till, minimal cultivation and ploughed plots which yielded 8.8, 8.3 and 8.1t/ha (3.6, 3.4, 3.3t/acre). But the trend was clear.
"We expected no-till to be cheaper and maybe not to cause a yield loss. But this yield trend is exactly the opposite of what we would expect and clearly needs further investigation," says site manager Nick Poole.
SMI
• Better soil care goal.
• Minimum cults best.
• 2.3m tonnes/year lost.
• Big enviro impact.
• Scope to cut costs.
• Management skill needed.
• Workshops and demos planned.
• £35,000/year start-up funds from EU for 3 years.
• £35,000/year for 3 years hoped for from EU to finance demos etc.
* Key players – ADAS, EA, Monsanto, Simba.
SOIL CARE
• Better soil care goal.
• Minimum cults best.
• 2.3m tonnes/year lost.
• Big enviro impact.
• Scope to cut costs.
• Management skill needed.
• Workshops and demos planned.
• £35,000/year start-up funds from EU for 3 years.
• £35,000/year for 3 years hoped for from EU to finance demos etc.
• Key players – ADAS, EA, Monsanto, Simba.