As with many things in life, regular maintenance yields better results than waiting until a problem requires serious attention. The same can certainly be said for pH correction.
And as growers approach the spring with stressed, underperforming soils – the result of poor autumn conditions – focus will switch to recovery and how to build resilience.
Nutrition will play a vital role, but equally, ensuring what’s applied is effective and available to the plant will also have to be addressed. However, achieving this to the maximum of its potential is only possible when soil pH is at 6.5, says Omya’s David McLellan.
“Acidic soil has a significant impact on crop productivity and soil health – Professional Agricultural Analysis Group (PAAG) data suggests that 40% of arable land is below the recommended pH level of 6.5.
“This is a problem as when pH becomes more acidic, nutrient availability in the soil drops, reducing the uptake by plants. This is because nitrogen stays in forms that are difficult for the plant to assimilate, or are lost through leaching,” he explains.
Alleviating lock-up
David says another outcome of acidic soils is the lock-up of phosphates, which again become inaccessible to the plant. Potassium can also remain fixed to the clay fractions of heavy soils.
Although farmers are familiar with pH correction, he believes it’s the frequency in which they’re doing so which is hindering results. “The classic approach is to apply agricultural lime around once every five years. But the lime is slow to correct soil acidity because it can take months to break down.
“This can be overcome by switching to granulated lime which is made from micronised particles with a high surface area which dissolve quickly in soil moisture. The higher the surface area, the faster the reactivity.”
Maximising spring fertiliser
Omya Calciprill (calcium carbonate) is a 2-6 mm granulated soil conditioner which promises to correct soil pH within weeks, delivering results in the first season of use. According to David, applying the product now will maximise spring fertiliser applications while providing calcium nutrition to the crop.
“Growers also benefit from improved soil structure through flocculation – calcium pushes clay particles apart which aids aeration and water flow.
“It can be applied using standard spreader equipment when convenient so contractors aren’t required. Annual applications of small amounts of Calciprill is an effective management approach and maintains an optimum pH for optimum NUE and yields” he says.
