Markets for high-value agricultural commodities are growing and can contribute to reducing rural poverty. However, the poor may be unable to participate in such markets, and adverse environmental impacts may counterbalance short-term benefits. Hence, policies are needed that help reducing poverty while protecting the environment. We address this challenge using the case of commercial maize production for animal feed purposes in a marginal upland area of Vietnam. We identify determinants of farmers’ degree of participation in maize production using regression analysis and assess farmers’ awareness of soil erosion and their conservation practices. The poorest are particularly specialized in maize but depend on disadvantageous input supply and marketing arrangements to offset infrastructural and institutional deficiencies. High awareness of soil erosion is contrasted by lacking conservation practices due to high opportunity costs. Policies should foster the integration of livestock in the maize-based farming system and promote soil conservation technologies that produce feed.