I'm unemployed.. but I have 6 rai of land...let's follow what I can do.

Look into exploiting the most useless parts of your land (shady parts under the sides of buildings, concrete areas, indoor sheds space not in use) to Vermiculture. It typically involves putting old newspapers and food waste in a barrel cut in half length wise, with a few breeds or earthworm and a little starter soil, to eat the paper and turn it into soil thickly laced with earthworms. You can choose to use it in your own soil or sell the earthworms. It's a fairly easy way to imlroveyour land and profits, and if you fail utterly at it, you are merely out of the cost of time and a barrel, and can still dump the surviving worms and soil back into your farmland.

The farmers I learned this from in Hawaii got a bonus, he got a few soecies of local composting bugs to join in for free and break down the paper and carsboard waste even faster than just the worms alone so he had a higher than expected turnover.

Also look into landscaping products like growing lilies or mantis shrimp (both in combination works). That's just concrete concrete blocks and a rubber liner down the length, gotta check the PH levels occasionally and feed the shrimp if nkt enough mosquito larvae is growing. Rich people like to buy that sort of thing fkr their backyard ponds.