You can keep extremely dusty operating conditions from reducing injector life very simply by using a better filter on the fuel-tank vent. A 2-micron breather filter is inexpensive, because air comes through it very slowly. The $15 filter normally requires replacement only once per year, and it can double the life of secondary fuel filters working on the worst sites.
Breather filters should be located near the top of the fuel tank's standpipe. Standpipes should have adequate height and extend deep enough into the tank to prevent fuel from sloshing into the filter.