I hereby declare it Underappreciated Combinations of SI Units Day.
To start with, what could you justifiably measure in meganewtons per hectare?
In reply to @christianp
A herd of cows coming in for milking.
A cow weighs about a tonne, or 1000kg, so a herd of 100 cows would apply a force of about 1 meganewton to the ground. When they're coming in for milking , I reckon they could all fit in a 100m×100m area, or a hectare.
In reply to @christianp
What could you justify measuring in microgram-metres per second?