fill the rear tires up with a liquid to add more
ballast weight. and get that extra weight closer to the ground. can help reduce COG (center of gravity) for a tractor.
going SLOW, with plowing, ya going to be in and out of the furrow made from last pass of a plow. and if you hit the furrow wrong ya going to be tipping over. the faster you go, less chance you might be able to steer to keep things going. along with faster you go more likely hitting a bump on high side or going into a hole low side and suddenly tipping over.
many tractors, you can either swap rear wheels (one side for other side) to keep tread in correct direction. and gain a inch or 2. (it is all in the rims) and were things bolt up to the hubs. to get a wider stance.
some tractors ya have to buy spacers. to get a wider stance for the wheels.
they do sale "tilt meters" that mount on tractor. to help "give you an idea" of what angle you are at. it is by no means lets ya drive tractor right up to max degrees before tractor rolls over. but helps give you a better idea of things.
having ROPS (roll over protection system) is always good. (of course wear seat belt when ROPS is up)
do not be confused with FOPS or sunshades. they will not give you any protection in a roll over.
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and of everything, do things in your own limits. if ya do not feel safe. then stop.
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and with texasjohn, has stated do you really need to put in a field at that steep of an angle? it might be better area for a pasture for live stock. than actually growing a crop. erosion can be a killer.