Robert Lawton was probably one of the first farmers in the UK to start precision farming and has been manually zoning and adjusting fertiliser rates for more than 25 years.
But the advent of better technology has made the job far easier, with the financial and environmental benefits stacking up with every extra improvement.
The first ever Linking Environment and Food (LEAF) demonstration farm, North Farm, Aldbourne, Wiltshire, extends to 1,500ha. Mr Lawton grows just under 1,215ha of wheat, barley, oats, oilseed rape, linseed and forage crops.
Although the downland soil is predominantly chalky, there is great variation within fields, which is where the biggest savings can be made through precision technology, says Mr Lawton. “Our average field size is 20ha, and we can have up to five different soil types in one field.
“We started out by manually adjusting fertiliser applications, which was very tedious and boring – but effective. If you take an average phosphate and potash level across a field, it will be made up of vast areas that don’t need any fertiliser, and smaller bits that do, so the savings can be absolutely huge. We saved about 50% on phosphate and potash costs alone. And, of course, alongside every financial saving is an environmental one.”
More recently, Mr Lawton joined forces with Vince Gillingham from the Courtyard Partnership, helping him to develop a complete package of precision technology that would be easy to use on farm. Intelligent Precision Farming (IPF), which includes soil mapping, yield mapping and an online tool to download GPS files for variable fertiliser, spray and seed rates, is now being used by more than 400 farmers.
Although Mr Lawton mapped his farm eight years ago using soil samples, Google Earth and crop records at a cost of £6.50/ha, it is now possible to do the same using soil brightness scanning at a cost of just £2/ha. Once the management zones are mapped, soil samples are analysed, leading to the creation of variable-rate plans for fertiliser, sprays and seed.
“We work directly with Robert and his agronomist, and offer advice on what’s worked well elsewhere, but the actual decision making is farmer-driven,” says Mr Gillingham. “As all the information is online they can log in and access files whenever they need them, download the information to a memory card and put it straight into the tractor’s computer.”
As the tractor travels across the fields, application rates are adjusted automatically, to reduce seed rates on fertile valleys and increase them on shallow chalk, for example. The aim is to get a more even crop, rather than save on seed costs. “Our wheat seed rates can vary from 150-350 plants/sq m,” says Mr Lawton. “And we have seen yields improve as a result.”
Over the past two years, Mr Lawton has used satellite images of the crop canopy, taken between February and May, to help identify nitrogen fertiliser requirements. He also has a yield mapper on the combine, meaning he can overlay yield maps with the seed and nutrient maps, to see how successful the programme has been.
“One of the key aspects to getting the most from precision farming is pulling all the information together properly,” says Mr Gillingham. “Too many people print yield maps off and put them in a drawer, but they are very useful in showing where the benefits are, or where they’ve been applying more inputs and getting no return. It’s a very useful discussion point at the end of each season, to identify what we can do better next year.”
Adopting every part of the IPF toolkit is also beneficial, he adds. “If you just do the variable seed rates, or fertiliser, or yield mapping, you won’t get as much benefit. It doesn’t cost a lot more to do all of it, and small percentages add up to a big change at the end of the year.”
Perhaps surprisingly, many farmers are already using machinery that has variable-rate technology. “It’s worth checking, as 50-60% of farmers who think they can’t do precision farming because their machinery isn’t up to it actually already have the equipment installed. Even if you’ve bought second-hand machinery, if it’s less than about eight years old it will be installed as standard.”
Installing GPS receivers on all the farm’s tractors costs between £2,000 and £15,000, depending on the size of the enterprise, says Mr Gillingham. It is also possible to retrofit variable-rate technology to older machinery, at a cost of about £1,500 for a fertiliser spreader, and slightly more for a drill. “Only about 60% of our customers have a yield mapping combine – you can retrofit one for £2,000-2,500, but most will opt for it when they upgrade their combine.”
Annual running costs range from £5.50-6.50/ha, depending on which firm farmers use, with soil sampling carried out about every three years. “Average savings for our clients across 40,000ha are £24/ha in phosphate, potash and magnesium fertiliser, £20/ha in nitrogen fertiliser and up to 10% improvement in yield through variable seed rates,” he adds.
At North Farm, Mr Lawton has taken precision farming one step further, by introducing precision driving. With the help of an R4F grant, he installed GPS on the farm machinery two years ago, to ensure centimetre-accurate fieldwork. “With more accurate tramlines we are no longer get any overlapping of seed or sprays, and we’re not missing any areas either. We’re saving 10% on fuel costs, which is a significant amount over our acreage.”
|Even more precise overseas|
The next step in precision farming evolution could be greater use of in-furrow fertiliser when sowing crops – something that is already widespread in Australia and America.
“It is becoming more common for people to apply fertiliser to oilseed rape at the time of drilling, especially where they are cultivating in seed bands,” says David Langton, technical manager at Agrii. “Placing fertiliser where the seed is, and not in the gaps in the middle, is proving to be beneficial as you’re feeding the crop and not the weeds.”
Australia firm Liquid Systems has developed a range of equipment to furrow-inject liquid fertiliser, trace elements, inoculants, fungicides, and other fluid products at seeding time. “By using our equipment which can be easily integrated with field mapping systems, farmers are maximising their productivity and minimising their input costs,” says chief executive Peter Burgess.
“Liquid starter fertilisers help kick the seed out of the ground, particularly when it’s cold – and in-furrow application of both fungicides and trace elements is a more effective and cost-efficient method than post-emergent spray applications.”
Liquid banding is particularly beneficial in dry soils, and also means farmers can apply pre-emergent spray, liquid fertilisers, fungicides and other products in just one pass, he adds.
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