Recently, financial assistance to farms has been widely under scrutiny. Agricultural assistance has an important impact on farmers' production decisions and those decisions in turn affect resources use or environmental quality. Surprisingly, the impact of agricultural policies on agro-biodiversity has been relatively neglected. This paper purports a novel framework to analyze the role of crop biodiversity on the mean and the variance of farm revenues. Further, the potential use of this framework in studying the impact of farm financial assistance to crop biodiversity loss is investigated.