Encyclopedias provide broad factual information on a topic. They can be particularly helpful when you don't know a lot about your topic. Gather important terms and concepts related to your topic to use as keywords when you begin searching for books and journal articles in the catalog and databases.
The easiest way to find encyclopedias in the Library is to browse our print Reference Collection. The Reference Collection is on the first floor of Hale Library, directly across from the elevators. Of particular interest for you will be the agricultural materials, mostly prevalent in the 'S' call numbers.
You can't check out materials in the Reference Collection but there is a scanner next to the collection that you can use to scan the article you need (for free). (And don't forget to also scan the title page so you have everything you need to make your citation.)