The final yield tally after dedicated energy crops are harvested gets a majority of the attention when evaluating these crops. Standing next to 12 foot tall grass and realizing big yields once the crops are harvested is always impressive, but Genera Energy appreciates the importance of waist high grass during the spring season as well.
Farming would be made much easier if every year was a bumper crop year, but realistic expectations and preparation for those extreme weather years when yields will be negatively impacted will make these challenges a bit more bearable. In an effort to plan properly, accurately assessing biomass supplies throughout the growing season ensures that we are able to predict yields as early as possible and successfully supply feedstock to our biomass conversion customers. Unexpectedly coming up short due to low yields is not an option. Unanticipated shortages could prove detrimental to operations and lead to unnecessary facility shutdowns and unstable operational costs. By projecting crop yields well in advance of harvest operations, any supply shortfalls can be predetermined and necessary preparations to source secondary feedstocks can be made.
At my prior job with USDA NASS, I worked as a crop yield statistician to estimate the yields of row crops throughout the year. You can only imagine how closely this data was watched by the livestock industry and commodity traders. The relatively young bioenergy industry, however, lacks the access to historical and monthly yield reports for crops like switchgrass and miscanthus. To ensure that we have a full understanding of the crops we produce, Genera Energy has developed an efficient and accurate method to estimate feedstock supply prior to harvest.
Several methods for estimating harvestable biomass have been established, with varying levels of accuracy, effectiveness, and feasibility. Remote sensing data can provide a high level of accuracy but can be very expensive and sometimes difficult to obtain. In-field sampling of clippings has also proven to be an accurate method of measuring harvestable biomass, but this method is destructive, laborious, and very time consuming. The visual obstruction (VO) method, however, integrates both height and density and has been vetted by several researchers as an effective tool for quickly, and more importantly, quite accurately predicting biomass yields.
By incorporating VO measurements as well as several other yield monitoring techniques into our crop monitoring program, Genera Energy has cataloged a history of several bioenergy crops’ growth curves throughout the year allowing us to make accurate yield projections and ultimately to make informed biomass supply chain decisions.
By Lance Stewart, Supply Chain Manager
