Straw from production of wheat is available for conversion to bioenergy. However, not all of this straw is available for conversion because a certain amount must be returned to the soil for conservation. County and state-wide inventories do not account for variation within farm fields. In this study, a technique is described that applies information from on-combine crop sensors into estimation of straw yield across fields. Straw yield could be predicted to within 350 kg ha^-1 (R² > 0.90) using grain yield, grain protein, and crop height as regression estimators. When validated in the field, the straw yield model provided a modest fit to the data (R² = 0.58). Further testing and development is needed to improve this technique and draw conclusions.