Along with installing a driveshaft Slip Clutch to protect from overloading the front wheel drive system on Belarus 400-series 4x4 tractors (420A, 420 AN, 425A, 425AN, T40A, T40AM) Wheel Weights, Tire Ballast & Drawbar Ballast also help in that regard by transferring a lot of weight & torque to the rear wheels especially with heavy loader use. Anyway, all tractors need traction and that's what you get with heavy Drawbar Ballast.
The simplest & cheapest Drawbar Ballast is probably sticking a 1" bar through a 55 gallon drum & filling it with concrete. A concrete filled drum weighs about 1,125 lbs but is pretty awkward to work with and has a high center of gravity unlike this 1280+ lb Steel Drawbar Ballast Box. This Ballast Box is especially useful for logging as the chains run nicely over the top yet it raises the lift point for large logs. It also serves well as a back stop & to push chained-on logs backwards when needed. It's also handy to step on to fetch chainsaws & tools up by the seat.
With this box I usually only need tire chains on ice & it also serves as an auxiliary safety/parking brake...& makes a pretty good Nutcracker too...come to think of it it'll crack most anything you drop it on.
13" wide x 15" tall x 26-1/4" long (nic bars, 32-1/4" long after adding lift bars)
1) 3/4" x 12" x 24" (weld to four verticals);
2) 3/4" x 12" x 15 (weld to 3/4" bottom);
4) 1/4" x 2-1/2" x 15" (weld to 3/4" ends);
2) 1/4" x 2-1/2" x 25" (weld to top of 1/4" verticals);
2) 1" dia x 3-3/4" (I drilled 1" holes in the 3/4" thick sides 5-1/2" from top & welded but a good weld will work if you don't feel like drilling out the sides...in which case the two bars can be 3" long).
17) 3/4" x 12" x 24"
1) 3/4" x 12" x 17-1/2" (leftover length welded to top weight). The top weight can be welded in to prevent spilling the weights but I keep a small chain on it to be able to borrow the 3/4" plates for other uses.