The Sorting Process

While we hope our research leads to viable low-cost strategies that allow insurance providers to assess pasture conditions quickly and with a relatively low amount of effort, much needs to be done by hand first to validate the accuracy of new methods.

To determine whether there is sufficient correlation between satellite-gathered NDVI readings and healthy, growing grass, our researchers begin by collecting grass from sample sites located around Alberta. The grass is clipped and put into paper bags labelled to tell the researchers precisely where and when that bundle of grass was collected.

Paper bags offer a few advantages: They’re cheap, can be easily written on, and are eco-friendly. They also make it easy for us to dry the grass before sorting—because the bags are porous (as opposed to their plastic alternative), we can keep the grass packaged and labelled while drying in the furnaces at the federal research station in Lacombe, AB.

Once the grass has been dried, it’s time to sort. This is where the real research is done: Each bag is completely emptied into a tray for a researcher to sort (blade-by-painstaking-blade) into piles of green grass, carry over material from past seasons, and forbs. It can take 1-2 hours to pick through one bag.


Researcher Rick McConnell sorting grass into piles of healthy grass, carry over, and forbs.

After sorting, the grass is weighed by the gram. By taking the average weight of all the grass collected from a specific pasture on a specific date, the researchers can calculate an estimated pound-per-acre of pasture production.

This information is carefully recorded in a ledger, as well as kept electronically.

The lb/acre measurement is crucial. It is against this number that our researchers compare NDVI. The hope is that as more green grass is grown on a pasture, the NDVI reading will reflect that growth with a correlating number. As the lbs/acre increases, so too should the NDVI.

If adequate correlation is found between lbs/acre and NDVI, researchers and insurance providers may be able to rely on the NDVI reading alone. That would make years of collected retrospective data accessible, and save others from having to deal with… this:

Plenty of work still to be done…

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