Double-cropping with winter camelina in the northern Corn Belt to produce fuel and food

Abstract

Camelina (Camelina sativa L.) can be used as oilseed feedstock for biofuels. Recently, it was shown that fall-seeded winter camelina can be successfully grown in the upper Midwest USA and may be harvested early enough in the following summer to allow producing a second crop. Double-cropping may offer a profitable means of producing a dedicated biofuel crop without jeopardizing food security. To our knowledge no published information exists on exploring double-cropping with winter camelina. Therefore, a 2-yr field study was conducted between 2007 and 2009 in west central Minnesota to evaluate the agronomic and economic viability of producing short-season cultivars of soybean [Glycine max (L.) Merr.], oilseed sunflower (Helianthus annuus L.), and forage millet (Setaria italica L.) after winter camelina in conventionally tilled and no-tilled soil. In most instances, yields of camelina and the second crop in the double-crop sequence differed between years but not by tillage practice. Averaged over both years, total oil yields for the camelina–soybean and camelina–sunflower sequences were 704 and 1508Lha−1. Compared to conventionally produced mono-crops, on average, double-crop soybean and sunflower yielded 82% and 72% of their mono-cropped counterparts, respectively. As expected, double-crop production costs were greater than for conventional mono-crops. However, in 2009 if camelina prices were similar to canola, net returns for double-crop camelina and soybean were $172–352ha−1 higher than for soybean alone, with highest double-crop net returns for conventional tillage. Furthermore, double-crop soybean seed protein content was little affected by late seeding, while double-crop sunflower oil content averaged over both years was about 13% lower than conventional sunflower sown at an optimum time. A winter camelina-food or -forage crop double-cropping system may be viable for the upper Midwest USA.