Site for instructions, albeit in German. But a big big thankyou goes out to them for making it available. I had already found how to put a few crops in prior to this but the instructions were not as good as these turned out to be, though both worked.
Basically you MUST INSTALL IN A MOD GAME, not directly. I'd do all work in an unzipped fresh game in a test folder on the desktop, that's how I did mine.
If you do proceed with this it is at your own risk. I cannot read German, but because of my prior attempts I know how it's being done so I can give you a few pointers to help.
You are supplied with a huds folder, a scripte folder (leave the "e" on the end) and a foliage folder. Let's assume you have a game called myGame and you unzipped it to a test folder on the desktop, so it would have map folder, vehicles folder and a few other files in the first window. Open the map folder and your game map would be in there with some other files, that is where you place the hud folder (it has some crop icons in it). You also place the scripte folder in there too as a folder on it's own not as a subfolder to one of the others. In your textures folder is a "foliage" sub folder, copy the contents of the supplied foliage folder to that one.
Now it's time to get down and dirty. Open your map.i3d in Notepad ++. You will deal with 3 specific areas and all are at the back of the present areas so easy to find. All files in there have ID numbers and the beauty of this is higher numbers than are already present in yours are initially used. Then if your game successfully starts with the new crops the program will change your high numbers to normal ones, unfortunately not as in an ordered list as you give it.
So we search for;
/Files
and because of the switch you're sent to the back or bottom of that section, best to perform a search to see if any of your proposed numbers have been used already, then change them to suit-I didn't have to do this in mine. Make a space by putting your cursor to the left of the /Files and hitting ENTER (not too hard). So you're pasting in some more files and you may need to tidy up a little, if you don't understand how any of this works then please do not attempt it at all. It could take years to explain it all, so it's better for people who are used to changing this stuff and know what to do. If you carry on, again at your own risk, go through the German examples and use copy/paste to paste in the files only at this point.
Once those are in and tidied (mostly all in a straight line for the files, 1 tab only may be needed for alignment). Do a search again but for /Materials this time. Once again you're at the end or bottom. Paste in the samples from the German stuff but only the Materials at this point. Once again tidy up as you think necessary to keep alignment with the rest of the Materials in there.
Finally I used <FoliageSubLayer as my search term, manually moved to the bottom of the FSL and pasted in there. this is the one to take the most care and time with. Some spaces between sections to takes out, vertical alignment to sort. Not forgetting the first line calls the procedure and 1-2 lines or so are the procedure then the last line is the end of the procedure so those insets need to be just right but they are easy to spot if you worked on this stuff before. Once tided go through them once again but IMPORTANT, the "densityMapTypeIndex" must increment by 1 only. So if yours has 1-8 in you're lucky since I think the German stuff starts at 9, 10, 11 etc. If not then you'll need to change them to 10,11, 12 etc if yours ends at 9.
Ok, now keep your old zip file to the right of the bin and rezip this one to put in your mod folder. Try it and if it doesn't work go back to the file to the right of the bin knowing that will still work. Either give up at that point or use that file to start over. Be aware one of my game plays didn't work with this, 3 of them did so the supplied details are pretty darned good. Just be careful and take your time. No offence but if you're mot practiced at stuff like this then don't go ahead.
If it does work then smoke a cheroot and put cher feet up. But not for long cos ya gotta fine seeders, harvesters, wagons, storage, sell points.....so STOP LOAFING ABOUT will ya? This is a WIP people...... Their's also allegedly a tool or 3 on the way to do it for you but that could be a while off yet.
I lost the addy again while writing this, but hey it is 4am ish. If not this one then just search for neue-fruchte 2013
http://www.modhoster.de/mods/neue-fruchte-fur-ls-13
Have fun.....