From what I can see and from my limited experience, you will be better off replanting coconut trees. I don’t think they are in a condition to yield 100 nuts per tree on average, whatever fertilizer you use. Moreover, coconut trees take about 3 years to fully respond to any manure/ care.
Here is what I would suggest:
- There can be up to 45 trees in an acre (Biju, correct me if I am wrong). You can start planting new saplings where you have space (ensure about 27-30 feet gap between trees).
- You can cut down the worst of the lot (10% of the total) and plant new saplings in their place. Do the same every year. This way, you will have a new set in 10 years. In case some trees respond to your care in the meanwhile and start yielding well, you can leave them alone.
- You definitely have to start intercropping. Bananas would be ideal. They have an annual payback and that can get you cash regularly. There can be 500 odd banana trees per acre.
- In addition to Banana, you can go for smaller plants like turmeric, chillies in between the banana plants so as to fill up the space. Do not leave any empty space.
- You can also start growing pepper on the more healthy trees. That way, you will have one more income source.
With this plan, you will continue to get cash from intercrops while the coconut trees recover. Coconut alone will never give you enough returns on the land cost anyway.
Disclaimer: I am no consultant/ hot shot farmer. I started farming about 3 years ago and inherited 100 sick trees that yielded 800 nuts a year. Now I am at 2400 nuts a year (at 24 nuts per tree, this is still way below what Biju quoted), I haven’t had to cut a single tree yet. Take a call after talking to more people.
Best of luck! Let me know if you execute a better plan.
This way, you will have a model