Here is a A Field of Oats

Stock Photo of Oats
Stock photo of a field of oats.

I found 1304 images for the term "Grain" at Acclaim Images.com.
They offer a variety of royalty-free, high resolution formats to choose from, and you can even order prints and posters through them!

You might also try clicking on any of the terms below to see related images:
agriculture,  field,  farming,  oats,  crop,  grain,  crops,  oat crops,  just oats,