I like the National Geographic software.
It works a little different than the others.
Instead of loading a topo into your handheld you load the topo onto your home PC. Plot the points you want as landmarks on the map and download the points to your PC. If you want a map print one with your points on it.
Works in reverse too. After a scouting trip upload your points to your PC. Then you can look at where you've been on a topo.
Each state costs about $100 and comes on 6 or 7 CD's.
I have the delorme PN 40 ,pretty happy with it. Kinda the same deal. Ithink I paid about $30 for unlimited downloads of thier aerial data packs, gives you aerial photos,satallite imagery and usgs7.5 min quad maps. You can go back and forth with your pc with the maps way points etc. It will give you the blm and gmu boundaries. Would be nice with a bigger screen.
I also use the National Geographic desktop software and like the ability to plot points on the map, look at 3D terrain and then upload a track to my GPS. Another nice feature that I realized since starting to hunt in Colorado is the downloadable GMU's. You can overlay the GMU boundaries on the map so you can easily plan your scouting.
Let me start off by saying I am not a farmer.
I am a deer hunter and I do own a tractor and have all of the equipment - but that does not make you a farmer any more than standing in the garage makes you a car - well, you get the picture!
Having said that - and with most of my ineptitude fairly well hidden - I do think that buckwheat is one of the most under rated cover crops out there.
I say cover crop because I see mixed results as it relates to the deer eating the plants.