From the USDA:
In our never-ending quest to satisfy the agricultural community’s and general public’s thirst for information, USDA Market News is collaborating with data.gov to add custom reports to our portal websites
USDA’s Agricultural Marketing Service (AMS) collects and publishes a high volume of market information for five major commodity areas. With the addition of the custom reports feature, we are offering tools that will help farmers, ranchers, and businesses be able to manage, sort, and view our data in a more meaningful way. You can drill down and generate tailored historical reports that include only the data points you need and also download it in a variety of standard formats, like XML or plain text.