Monday, 15 February 2021

The importance of robust nutrient advice


Without scientifically robust nutrient management advice, farmers’ livelihoods may be impacted. Ravensdown shareholders rightfully expect sound advice from us as it is part of the reason why the co-operative was formed by farmers in 1977.

So, how does Ravensdown ensure our advice is indeed scientifically robust? In terms of understanding the performance of different fertiliser products we are guided by the scientific rigour of respected scientists such as the late Dr Alan Sinclair. In 1991 he published on the importance of recognising biological variability in any field experimentation comparing different nutrient sources.

Dr Sinclair explained that if you were to look at on-farm pasture yield differences from a range of P fertilisers, differing in terms of P availability by say 10%, then you would need to consider 40 replicates to be certain you could determine whether any yield differences were statistically significant with a 90% probability.

By contrast, how often do we see various product claims being made in the farming press with little, if any, supporting evidence with respect to statistically robust replication? 

It will come as no surprise to shareholders that we are regularly alerted to a host of fertiliser product enhancements, both from domestic and international entities, where the benefits claimed are numerous and varied. We rightfully and dispassionately scrutinise each opportunity. The basis for the evaluation is to look for the principal effect and the accompanying science mechanism to establish whether the effect is repeatable and statistically robust. It also needs to fiscally benefit both the farmer and Ravensdown to warrant our involvement. 

 This scrutiny is not without cost, and where the products and/or concepts are seen to have merit, Ravensdown is willing to invest on its shareholders' behalf to undertake the necessary work to prove it is fit for purpose. This approach allows for a range of product enhancements to be evaluated, including those from small promoters who may not have the budget facilities to undertake the research on their own. Most of this evaluation work is undertaken under contract with recognised research providers such as Crown Research Institutes and universities who have the required resources, experience and capability. If we are not satisfied, we politely decline to the chagrin of the promoter, but of more importance, we safeguard our science integrity so our shareholders can have continued confidence in our advice.

The final step is the technical training we provide to our people who then provide the nutrient advice to our shareholders. We have eight university-level training courses being delivered by Massey University staff with a further three in development. This is accompanied by a nutrient certification system involving examinations, audits and continuing professional development requirements.

We believe this approach enables us to deliver robust nutrient management advice to our farmers who have never needed a trusted source of products and advice more than they do today.