Unfortunately, the article text provided is incomplete and does not contain enough information for me to generate a comprehensive summary. The article excerpt starts with a section heading "The crop model: cash and bioenergy crops" but does not provide the full text of that section. To create a meaningful summary, I would need access to the complete article text. Please provide the full article, and I will be happy to generate a well-organized, concise summary that captures the main points and key details while adhering to your specified guidelines.