Granular lime can be spread all year round
By Andrew Blake
A NEW form of lime offering several advantages over other materials used to counter soil acidity has been launched.
G-Lime from Lafarge Redland is similar to a granular fertiliser and, unlike most ground limestone and chalk, can be applied accurately through conventional distributors.
A key benefit, according to one supplier, Richard Burt of Worcs-based Acorn Arable, is that it can be spread any time of the year when ground conditions allow.
Liming contractors are finding it much harder to fit their main workload into the shrinking autumn post-harvest/pre-sowing window, says Mr Burt who farms 1400ha (3460 acres) of arable near Pershore.
"We are harvesting later and drilling earlier." The new German material means growers can do the job themselves when more convenient, he says. "It cuts the hassle of lorries delivering heaps to field headlands and helps reduce compaction."
Created from screened and compressed ground limestone G-Lime contains only particles below 100µ diameter. This means all its calcium, magnesium and trace elements are available to crops within three years, says Lafarges Bill Brogden. Depending on source conventionally produced lime usually has only 20% of its particles that fine. "Anything above 150µ doesnt become available for at least three years. There is a sliding scale of efficiency."
Because of its effective concentration, application rates of G-Lime are likely to be a fifth or less of that normally needed to achieve the same neutralising effect. "Our standard recommendation is that if you have been using 1t/acre you need only 3cwt," says Mr Burt.
The new product is sold in 0.5t bags and at £98/t is priced to compete with the average "delivered and spread" cost of conventional materials. Minimum order is 0.5t, which could make it especially attractive to grassland farmers and vegetable growers needing to sweeten small areas without resorting to contractors, he adds.
Environmental pressure on dusty operations like traditional lime spreading is growing, says the Agricultural Lime Association.
Granular lime, which is much less susceptible to wind blow and costs less to haul, is widely used on the Continent and in the US, says Mr Brogden. "The main problem in this business is the transport cost. The recent rise in diesel price caused major problems."
Mr Burt believes granules will prove particularly useful in precision-farming techniques based on detailed soil mapping. Acorn already offers the SOYL system, correcting specific potash and phosphorus deficiencies with straights applied by satellite-guided applicators. "We use triple superphosphate and muriate of potash. G-Lime is the missing link for correcting pH on the go." *
• Granular pH correction.
• For normal fertiliser spreaders.
• No need for contractor.
• Less soil compaction.
Richard Burt (left) and Bill Brogden say granular lime (inset) means growers can easily correct pH themselves.