I just have bronchiectasis and my MAC test turned out negative though my CT’s look like I have it.
I asked my doc last year if I can garden. Keep in mind…VERY tiny scale compared to you. He said he didn’t think he should forbid gardening if I enjoy it, but I should be careful… wearing mask, etc.

It’s known that soil and water, especially if sprayed/aerosolized, contain MAC. Wearing a mask, long sleeves and glasses and gloves would decrease exposure. I do these and if I’m doing dirty work, I wear a face shield. The shields don’t stop the tiny aerosols, but do block larger droplets and provide splash protection. Sue, a moderator here, gardens avidly and I use some of her ideas and take off the clothes I worked in before coming into house. I try to avoid emptying bags of soil and wet them from a few feet away to Cut down on dust.
If you can get someone to help with the higher risk things that would decrease your exposure and risk.
Tracestew had good ideas.