You can find scholarly research by searching a large multidisciplinary databases or by a searching smaller, agricultural database.
There are advantages to each database. If I'm really trying to be thorough, I will utilize several databases.
Note: There may be significant, but not complete, overlap in coverage within these databases.
Best Databases for Finding Agriculture and Food Science Research
Washington State University Libraries' Catalog (Search It) locates pretty much everything you'd hope to find on a subject. This includes journal articles, books, newspapers, multimedia, extension resources, archival materials, etc.
Web of Science is a very powerful, mostly STEM, database. It is great for finding scholarly research. There is also a lot of useful advanced functionality for those who want to dive deeper.
AGRICOLA is an agriculture specific database provided by the U.S. National Agriculture Library. There is a paid version that links to full-text access. There is also a free version called SEARCH.
If you are interested in a full list of databases available from WSU, check out this list.