Co-existence at the silo: “Farmers and regional elevator operators need to cooperate”

Interview with François Coleno, research manager, INRA and researcher in Co-Extra Workpackage 2.

François Coleno, INRA
François Coleno, INRA

In order to segregate GM from non-GM crops, co-existence measures are necessary at farm level and include the establishment of minimum isolation distances and the cleaning of machinery. However, during collection, crops from many fields usually are combined to fill the silos of European grain merchants. Therefore, at this stage of the supply chain, management strategies also are important to avoid the risk of admixture. François Coleno, researcher in Co-Extra’s Workpackage 2 (supply chain analysis) uses supply chain simulation models to search for the most efficient form of management while considering the costs involved.

Mr. Coleno, in the context of co-existence of GM and conventional maize, the debate is dominated by the issue of avoiding admixture through the separation of fields. You argue that this focus is not sufficient for evaluation of the real costs of co-existence. Which aspects are missing in the debate?

Coleno: Co-existence generates several problems across the supply chain. On the farm, the use of the same agricultural machinery and the risk of natural cross-pollination between GMO and non-GMO fields can lead to admixture. This risk can be reduced by introducing a time lag between the growing of GM and non-GM crops or by creating isolation distances based on the short flight range of maize pollen between GMO and non-GMO fields.

Maize field: Co-existence measures start here with e.g. minimum isolation distances between GMO and non-GMO fields
Maize field: Co-existence measures start here with e.g. minimum isolation distances between GMO and non-GMO fields

However, a bigger problem lies in the link between the farm and industry – the regional elevator operator, or grain merchant, whose infrastructure is the site of the highest risk of admixture. This can lead to financial losses for the elevator operator, since he pays the farmer a "non-GM" price but may have to resell the same goods as GM – at a lower price. Insuring proper segregation is possible, but cost-intensive. My work focuses on estimating these costs and identifying more efficient collection strategies.

Could you describe the different collection strategies?

Coleno: My model covers the collection period when farmers deliver GM and non-GM maize to elevators in collection silos, forming batches of GM and non-GM maize with the deliveries. These batches are first dried, then stored. The model calculates the quantity of GM and non-GM products at the end of the process, taking into account that non-GM products mixed with GM have to be treated as GM. The model also calculates costs related to collection, such as transportation costs.

I have considered three strategies. The first treats the batches as they arrive. The second is a temporal one that allocates a time period for each group, such as assigning the first month to the collection of GM products and later periods to the collection of non-GM products. The third approach – a spatial strategy – sets aside separate parts of the infrastructure such as collection silos and dryers to each product group. Farmers have to deliver GM to GM silos and non-GM to non-GM silos.

Elevator: Strategies are needed here to reduce admixture risk
Elevator: Strategies are needed here to reduce admixture risk

Which costs result from these strategies?

The first strategy doesn’t lead to any cost increase, but treats only 20-60 per cent of non-GM according to the proportion of GM and non-GM in the deliveries. The temporal strategy also causes no cost increase while allowing the treatment of 72-100 per cent of non-GM products. The spatial strategy causes a 700 to 800 per cent increase in transportation costs alone and treats 90-100 per cent of non-GM. The last two strategies also increase transaction costs between elevator operators and farmers. These costs are not estimated in this work. Additional costs also arise from the fact that regional elevator operators contract with farmers to make sure that these produce what the operators expect. However, companies have to make a trade-off between the different strategies, taking into account the risk of admixture and the costs involved.  

What is your overall conclusion? How can elevator operators overcome the difficulties in segregation?

To overcome segregation difficulties, the infrastructure needs to be specialised, either by timing GM and non-GM deliveries, or by defining GM and non-GM zones in the region and its farming infrastructures. Both solutions are possible, depending on the actual regional situation. However, both will lead to an increase in collection costs, due to higher costs in transportation and lower flexibility in the collection process.

For the optimal collection strategy that takes into account the cost management of segregation in the elevator supply chain and GM land management, there needs to be a debate about land governance. Farmers and regional elevator operators need to cooperate and elaborate a strategy tailored to their situation. The spatial strategy surely would lead to a more homogeneous landscape, minimizing cross-pollination at little cost to farmers.

More information: