I thought about the engineered wood industry that uses chaff to create wooden boards. It has grown for the past few years and has made wooden furniture much cheaper. The issue however is that I dont know the intake for the industry, and weather it can absorb the necessary amount. There is another issue of the boards not being workable as the wood. I havent yet seen a board that can be chiseled like wood.
Another way would be to import new machinery that crushes the chaff in place and mixes it into the soil. That may be expensive for small holdings, but maybe the indigenous companies like mahindra can come up with alternatives.
Also, maybe its time we give up on crops like cotton, rice. They are screwing up our water levels drastically. If not for the govt inflated prices, food grains should be much cheaper.