October 10, 2007
When Fife farmer John Weir started using SOYL's precision nutrient management service to test his land's nutrient content, he was amazed at the variance across similar soil types.
John Weir called in SOYL to test his land at Lacesston Farm, Gateside, Fife for P, K and pH levels in 1997 and by variably applying nutrients ever since he is saving money on inputs, while ensuring crops receive exactly what they need.
"Potatoes are a mainstay of the rotation here and I was concerned that we were over-applying lime ahead of the crop. Too much free lime in the soil can increase the risk of scab and I was keen to ensure this was managed correctly," he says. "When we had the first results it was amazing to see the variability across similar soils."
Results of SOYL's soil tests on Mr. Weir's land revealed potassium levels showed the most variance followed by quite variable pH levels. Although the phosphate content was quite even, the tests confirmed his own suspicions that, because he grows potatoes, it was actually quite high. This gave him the confidence to reduce P applications on grass and other crops.
"In the first few years I had a contractor apply the P&K on the most variable land using an automatic, GPS-linked spreader, while I applied the fertiliser to the less variable land myself, making manual adjustments according to the recommendations on the colour-coded maps. A contractor also variably applied the lime, according to SOYL's maps," he explains.
By 2005 Mr. Weir was so convinced of the variable spreading benefits he bought a new spreader to do the work, plus a Patchwork BlackBox that provides the GPS positioning and varies the application rates according to the treatment plans.
"The connection from the BlackBox to the spreader works very well," he adds. "SOYL emails me the map and I upload that into the unit via its docking station. It is very simple to use."
The SOYL treatment plans are based on soil tests, previous cropping and off-take as well as future requirements and the rotation. Mr. Weir now purchases straights and another benefit of the system, he adds, is it even calculates the total amount of each he needs to buy to match the variable applications. This handy service, he says, not only saves time but is very accurate, too.
Lime is still applied by a contractor, but only once in the rotation. Mr. Weir applies P&K variably himself, either annually or every other year depending on the conditions and the rotation. While Mr. Weir says it is hard to determine whether the technique has lifted yields, the recent addition of a yield monitor on his combine and mapping will help monitor any changes.
"But we have definitely saved fertiliser costs. Firstly by buying straights we are only applying exactly what the crops require and also we have saved phosphates right across the farm. The potash is also targeted more precisely," he adds.
The costs of variably applying the fertiliser, with the new spreader he says are probably no higher because he would have upgraded to a more accurate machine anyway. Also the BlackBox doesn't just control the spreader; he also uses it for guidance and it provides irrefutable proof of what has been applied and where.
"I really need this for the crop assurance schemes and by using the SOYL recommendations I can justify and prove that quantity of P&K we are using is required by the crop. We are applying no more or less than it needs. Also we are in a Nitrate Vulnerable Zone, and I reckon it won' be long before this is extended to other nutrients as well," he concludes.
Lacesston Farm, Fife
80ha Spring barley (Oxbridge, Optic)
50ha Potatoes (Ware for pre-pack)
20ha Winter wheat (Robigus)
20ha Oilseed rape (Castille)
Winter wheat - 9 t/ha
Oilseed rape - 4 t/ha
Spring barley - 6.2 t/ha
Soil types: mainly sandy loam across rolling hills.
Ability to target inputs more effectively
Cost savings and more effective use of fertiliser
Savings through effective targeting of lime
Full justification for the application rates
Precise record keeping
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