There are other mulching techniques besides using grass clippings. Many gardeners on the mainland use wood chips, but they aren't available here too often. Locally I've seen gardeners using cardboard, newspaper, shredded paper, weed cloth, black plastic, and carpeting. But there's one more thing that most people overlook --- living mulch.
Living mulch is just what it sounds like. It's plants. The idea is to have mulch plants growing as a ground cover. I've heard of some people trying white clover, strawberries, and creeping thyme as a living mulch, but I haven't heard how their results turned out. What I've tried myself is sweet potatoes.
Sweet potatoes are easy for me. They grow year around. They stay fairly low so that other crops can grow through them. They cost me nothing to propagate. I can pull out the excess and feed them to my livestock. I can harvest greens for our own table, plus harvest a few tubers too.
I've only just begun to experiment using sweet potatoes as a living mulch. The first crop I matched to them is taro. Taro is a long season crop, taking 9 to 12 months till harvest, and while taro can't compete with grass and most weeds, my taro seems to do fine with sweet potato vines growing among them. The taro towers above the sweet potato vibes, and the vines do fine in their shade.
My only issue so far is that I'm not brutal enough with the sweet potatoes. I tend to try to avoid stepping on them. But there are times when I need to clean up the taro and remove excess sweet potato greens. I still inwardly cringe when I step on the vines. Eventually I'll get over it, I hope.
While the sweet potatoes don't keep the soil as moist as the grass clippings, nor do they block out other weeds as well, the vibes seem to do pretty good as a living mulch. They definitely shade the soil and protect it from the sun and wind. They let the rain through. And if the soil is already fairly weed free, few new weeds survive to grow up through it. I don't know yet if the sweet potato vibes help the microbes, soil insects, and worms.
I'm fairly optimistic so far with this experiment. I think it's worth repeating, expanding, and trying with some other crops, possibly turmeric, sugar cane, pineapples, and bananas to name a few.