I am a hobby grazier, always out working in the paddock, fencing, picking up fallen timber, burning, digging and sweating. I currently plait my hair to wear under my hat, and use water only to rinse the sweat and dirt out every day.
I wash it with homemade tallow shampoo bar once per week.
Any tips for hair care on the farm?
I've had a pony tail of varying length for about 25 years. When it's short, I just tie it with an elastic hair tie band. When it's long, I tie it, braid it, and tie the end. Braiding it keeps a lot of grass clippings, dust, dirt, etc, out of it. If it's loose, it gets into stuff, and easier to get caught on things like tree branches, nails in rafters, ductwork supports, etc.
Take it out and wash it every morning (or evening if I'm sweating all day). If it's long and I'm working around moving machinery, I wrap it up and tie it short. If I'm working around moving machinery often, I'll cut it shorter for safety reasons.
Both of my daughters had long, blonde hair down to their knees when they were small. We had to wash it, brush it, and re-braid it when wet to make it easier. Almost nightly ritual. When they go 10ish years old we made them take care of it themselves. Once they had to do that, they soon asked if they could donate their hair to Locks of Love, a charitable organization that provides hair prosthetics to children free of charge.
Get to Know Us Mission & Vision Locks of Love is devoted to helping every child suffering from medical hair loss, thus we do not discriminate as to the cause of hair loss. We list the following information in an attempt to explain types of hair loss and specific needs of individual recipients...
locksoflove.org
They've each donated several pony tails to that organization over their lives. Maybe 10 between the two of them.
My shampoo of choice for about 30 years....

(why are the emoji's bald?)