The farmers in this community raise corn, soybeans, wheat and alfalfa/hay. If you're going to include crops in your artwork, please use these crops - other crops wouldn't make sense. As for color use, please stay away from corporate colors for John Deere, Case IH and Ford New Holland (all farm implement/tractor companies). If you don't know those color palettes, please look them up online first before providing your color recommendations.
In conversations I've had with the client, I've been told they prefer typefaces with serifs over those without serifs. That's not a mandatory requirement, but goes to their more "conservative" nature, I think.
One last thing ... in my previous logo contests, I've had artists submit work that was either a direct copy of a logo easily found online or a direct variation of another logo design submitted by a competing artist. I've made this contest a "blind" contest for that reason. I will review each logo I like through Google Image Search to make sure the logo/mark is not already in existence. If I find work that is a copy or direct derivation of existing work, I will ban the artist from the contest.
So please submit original designs only, please.