There is a lot of great information available on the open web, users just have to be diligent about being sure they are looking at reputable and reliable information. On this page are some resources to consider for your topic.
One of the keys to ensuring that you find reputable information through Google is to take advantage of the many search tricks available. For example, if you know you want information made available by the U.S. Department of Agriculture, you can limit a Google search to the USDA's domain by typing in:
This will ensure that all of your results come from USDA websites.
Test it out! and if you're interested in other tricks to using Google effectively, click on the infographic below.