Second-generation biofuels will be developed using cellulosic feedstocks rather than grain or oilseed crops that can also be used for food and feed, but to be sustainable, production of these feedstocks must not degrade soil, water or air resources. Simulation models can be useful for designing sustainable management systems, but field trials are crucial for validating predictions. Removal rates ranging from 0 to 7 Mg ha-1 were achieved in a multi-location corn stover harvest strategy study. Average N-P-K removal was increased by 23, 2, and 29 kg ha-1 for continuous corn and by 36, 4, and 27 kg ha-1 for rotated corn at the Ames site. Glucan and xylan, accounted for up to 60% of the chemical composition, while galactan, arabinan, and mannose constituted less than 5% of the harvest fractions. Drought was a major limiting factor at the Florence, SC location. Storms accompanied by high winds prior to harvest resulted in extensive lodging and major harvest problems throughout MN. Adverse weather conditions also limited the cobs only treatment from being implemented at 2 of 3 sites near Morris, MN. At the Brookings, S.D. site, cover crops did not have a negative impact on corn yield during the 2008 growing season. Soil resource assessment protocols were established and will be shared with baseline characteristics for some of the sites. Photographic images were taken where possible to assess soil cover. A long-range vision whereby multiple feedstocks are integrated into an entire landscape will be discussed as an ultimate goal for sustainable management.
This was presented at the American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America Annual Meeting, Pittsburgh, PA, November 1–5, 2009.