Article taken from Agronomist & Arable Farmer, June 2017, written by Chris Lyddon.
David Wakefield's Cambridgeshire farm is being used by Agrovista to test which of the latest precision farming techniques work best in a real-world situation.
Lewis McKerrow, Agrovista's head of precision technology, said the aim of the PTRx trials (the PT stands for Precision Technology) was to discover how these techniques integrate into the agronomy of the farm.
Wakefield explained that, like many, at one point the farm was very profitable with a very short wheat and rape rotation. ""We just milked the system for 30 years," he says. ""Black-grass has come to kick us in the teeth. We are now trying to get out of the mess.
""Chemicals don't work. Some of the best black-grass chemicals have been withdrawn from the market.
""We have gone to three crops now, starting with first wheat after a break crop. The second break is winter wheat if at all possible, but if the black-grass pressure is too great, spring wheat or spring barley, followed by a true break crop.
""At the moment we are growing winter beans. This year we have got linseed in the ground.
""Brown rust is the controller of what is actually put in the ground. ""As much as half could be spring cropping if blackgrass is bad. ""We are seeing a big reduction in black-grass. Ploughing is very expensive, but it is working and if I don't spend money on chemicals, I can spend it on ploughing.""
Wakefield notes that spring beans are effective at smothering black-grass due to the speed of growth, while different techniques have had varying degrees of success. He started deep cultivation in 2002, which was 'successful for a while' before switching to min-till.
""The black-grass got horrendous," he says. ""The top two or three inches went rock hard under direct drilling. We did some trials with the plough and we did seem to be sorting it out.""
Wakefield praised the three-crop rule, but he does have concerns over greening regulations on the cost of cover crops. ""We cannot see how three months in the soil with a little plant is going to have any advantage," he says.
Wakefield started to yield map his farm 13 years ago, covering all the soil. Without a variable rate sprayer, he was able to manage the rate of application by adjusting the speed he drove the tractor.
His enterprise is now fully guided after investing in a Trimble system, in which guided tractors are linked to sprayers, fertiliser sprayers and drills. They had been using an N-Sensor, but now they're trying out an Isaria device, which provides information on how much nitrogen to apply.
""We have got to farm the old-fashioned way, but using new technology.
""You've got to have history, though," Wakefield adds. ""There's no point having a one-year map. We have got 13 years of maps.""
McKerrow explained that the PTRx trial would be beneficial for gaining an insight into how the technology works on farm and gathering real-world data.
He says: ""Precision technology relies on the distributor doing a lot of the research and development. It is more about a system or strategy approach.""
For example, soil conductivity scanning would have no return on investment without a use strategy, or a drone flight would have no ROI if you don't use the data.
""What is the overall return on investment of these components?," he asks. ""We really need to get back to attention to detail. We need to be as efficient as possible.
""We employ our (Veris) MSP3 soil zoning machine.
""There is a lot of data that we collect with that one pass over with the machine. The first port of call was variable rate of seed.""
The base seed rate was about 130 kg a hectare, with 165kg/ha at the top end and around 100kg/ ha at the bottom.
Plant data was collected at six points, which revealed the highest seed rate produced just 47% germin ation.
McKerrow notes that although the spring had been cooler than the long term average, it was 20% warmer on the previous year. The dry conditions saw lighter land get short of water while heavier land did much better. A day of heavy rain prior to our visit increased the soil moisture to ""levels where'd we want it to be"", McKerrow says.
""What I see expanding is the connectivity area and the data transferred to one from these machines," he adds. ""If you look at what they are doing in America, the term 'trusted adviser' is used."" In other words the farmer has to give permission for use of the data, as it is - after all - their data.
McKerrow highlighted the difference between a strategy meant to 'imp rove' with higher input/higher output and an 'optimise' strate gy, designed to maintain output with reduced inputs.
An improve strategy had improved yield by two tonnes a hectare in one zone, while the optimise strategy had generated a field saving of £450 on inputs.