Here are a few of the outstanding resources they share with teachers EVERYWHERE (not just in VA).
Math Ag-tivities contains more than 130 pages of lessons and reproducibles for grades K-6. Each lesson incorporates interesting information about agriculture along with the mathematics concepts. Students gain skills to solve math problems while learning agricultural facts about livestock, various commodities, and plant growth.
The Garden Chef: Cooking Through the Food Groups provides teachers with a cooking and activity book that incorporates skills from the core subject areas. This book is divided by the five major food groups: Grains, Vegetables, Fruits, Milk, and Meat & Beans. The recipes feature nutritionally wholesome foods and contain extension ideas for teachers to use in elementary school classrooms.
Barnyard Banter is a collection of quick lessons and activity ideas to accompany 29 different books with an agricultural theme.
Jump Start Your School Garden is a guide intended to help educators integrate the use of the garden - whether it is an outdoor garden or an indoor container garden - into their science and mathematics curriculum. Additionally, tips and suggestions have been included for schools who hope to begin a garden or to enhance an existing one.
You'll find many more resources, like a searchable lesson plan database and extensive booklist, on their Teacher page. On the Volunteer page you'll also find some quick, fun activities.
I know I've left you much to explore, but before you go, have a bit of fun with the Peterson Brothers and think about how important agriculture is to each and every one of us.