dogleg

Hi All.
I haven't turned a sod since I was a kid but have been reading this forum with growing interest. Thanks to all contributors.

To get me started, the missus has about 4.5 rai with coconut palms planted in a six metre grid. They are from 2 to 10 years old.
The bigger trees leaves touch and I guess they all will eventually - if I don't kill them first!
Thing is, I think, they are not producing much and I reckon the petrol for the strimmer cost more than the coconuts bring in.
Does anybody have any ideas what a thick, lazy type like me could plant {and almost forget} in between the 'nuts with the aim of helping the soil, maybe displacing some weeds and possibly getting something edible even.

Apart from rain, as it is now, water would have to be hand carried in.
BIL tried to grow cassava their a few years ago but didn't grow too well.

Thanks,
dogleg

edit: near Huay Yai, Chonburi.

Sorry for ignorance, but have seen 'EM' mentioned all over the place ref fertilizing/composting. What the heck is it?

Just to warn anyone using the new PPT station on Huay Yai Road (at the south end of the railway road).
The attendant attempted to rip me off for 200B yesterday evening by entering 800B in the pump and hoping that I would hand over 1000B that I he had confirmed I wanted.
I thought it was strange that he asked me to pull forward more than normal for my filler cap position. Then he stuck his head in the rear window instead of the open front window - keeping his body between me and the pump display (maybe he had already caught me with the 50B already on the counter scam?) and went for gold. After confirming my order for' neung pan' - 1000B - he swiveled round and started up the pump. At the same time, his side-kick appeared at my front window and attempted, pathetically, to engage me in a distracting conversation.
Luckily this odd behavior alerted me so I got out of the car to see that he had entered only 800B. When challenged he immediately 'remembered' the 'neung pan' and added another 200B of petrol.
I'm sure this isn't the first, or last time for this to be tried. Another time I may well have been distracted enough to just hand over the money expected and drive off.
Be Warned!