Article taken from Agronomist & Arable Farmer
Agrovista is offering a new service that measures soil organic matter content to help growers pinpoint areas for improvement
The decline in soil organic matter levels in UK arable rotations has been well documented over the past few years, to the point where scientists from Sheffield University predicted in 2014 that if current cropping practice continued, the UK had just 100 harvests left. Although the loss of organic matter is only part of the story, and there are moves afoot on some farms to turn things around, the message cannot be ignored. With all this in mind, for the past three years Agrovista has been examining the use of cover crops and alternative rotations to help farmers improve their own particular situations, says head of precision technology Lewis McKerrow. ""One key point to note is that basing decisions on average field levels of organic matter isn't good enough," says Mr McKerrow. ""Over recent decades, fields with quite different soil types that would have been managed very differently have been amalgamated. ""It is unusual to find a completely homogeneous field in the UK; often organic matter levels can vary significantly across a field. The problem is that we have been unable to quantify this variation without resorting to impractical levels of laboratory analysis."" However, a new service from the Plantsystems technology arm of Agrovista is about to change all that. The service uses a novel machine from US firm Veris Technologies called the MSP3 that can measure pH, electro-conductivity (an indicator of soil type) and organic matter. These three components are key indicators of the yield drivers within a field and indeed across a farm. The machine can also be used to produce detailed zones of nitrogen leaching and water holding capacity. ""The beauty of this MSP3 is that it collects all this data as it is towed along behind a tractor," says Mr McKerrow. ""The job is very quick — the machine is pulled at up to 16 km/hr, typically in 12m bouts, so a massive amount of data can be captured in a day:'
Electro-conductivity and organic matter readings are measured constantly, while the pH is read about 15 times per hectare via a shoe that is raised and lowered into the soil. At the end of each field a number of locations are selected within it where pH/electro-conductivity/organic matter readings were among the lowest and highest. These areas are sampled by hand and sent to a laboratory. ""This ground truthing enables accurate calibration of the remote-sensing data, enabling it to be interpreted and analysed as precisely as possible," he explains. ""The data can then be assessed and used for either variable rate applications or management decisions about where to target inputs such as organic manures and cover crops:'
ELECTRO-CONDUCTIVITY MAPS
There is a strong case for organic matter being correlated to yield, although other soil parameters can be as significant, or greater, drivers of yield, says Mr McKerrow. Soil variations highlighted by electro-conductivity maps are often very close to where yield variations occur. That said, one soil with a high electro-conductivity and high organic matter can per-form very differently to the same high electro-conductivity soil which has low organic matter, he adds. ""There is no doubting that knowledge is power," he concludes. ""But to gain that know-ledge, information has to be analysed correctly and managed well. The risk of data overload is very real for many, but the evolution of better software solutions such as Agrovista's MapIT Pro software helps make sense of it all:'