At-Harvest Yield

The "At-Harvest Yield" product provides an end-of-season simulation of yield in production per acre assuming that future weather patterns are going to be similar to an area's climatology. Like the At-Harvest Acreage product, the At-Harvest Yield product becomes available in the latter part of the growing season. In contrast to the apparent yield, the at-harvest yield will vary up and down in value as the season progresses. However, as the season comes to a close, the apparent yield will gradually be the same as the at-harvest.

As mentioned in the introduction to the products, CropForecaster uses deterministic models to estimate crop development and growth, with yield being an output. These deterministic models simulate the properties and processes of crop phenology including its stage, biomass, leaf area index (LAI), and production per acre. The models work on the premise that there is a theoretical "phenotypic" yield, which represents the most attainable production for an area's climatic history, soils, and best management practices. If weather resources are limited in a given season, then the at-harvest yield will be less than the phenotypic or maximum value. The CropForecaster deterministic models use the real-time, forecast, and climatological patterns to compute a yield relative to the phenotypic value across the US. An example of the At-Harvest Yield product in map form is shown below at the county scale for the conterminous US on June 30, 2008.

The CropForecaster service is unique in that it provides a daily estimate of the at-harvest yield well in advance of harvest. Furthermore, all the products are integrated through the structure of the models. For example, as at-harvest acreage is reduced relative to the at-planting acreage through the season due to abandonment, because of weather or economic events, the at-harvest yields will reflect these changes in acreage.