Quality assessment test on the way

17 October 1997




Quality assessment test on the way

IDEALLY an extra method is needed for assessing quality, says Mr Annis.

"Currently there are moves within Europe to develop a standard reactivity test. This laboratory exercise measures the amount of acid neutralised by a sample within a given time. From it, a reactivity value can be calculated which takes into account both neutralising value, size and relative hardness of the lime.

"As expected, the work to date shows conclusively that materials which are finely ground or which are geologically soft have higher reactivity values.

"But the test must mirror what happens in the soil," he stresses. So the results are being compared with extensive Norwegian pot trials carried out over many years using a wide range of liming products.

The Norwegian trials produce reactivity values based on true soil reaction and plant growth, he explains.

"So far there has been good correlation between these trials and the laboratory reactivity test. So the lab test could provide a reliable and worthwhile assessment of a materials value.

"We hope that the reactivity test can be perfected and introduced as a European standard. It could be a valuable aid to growers when they buy this essential input."


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