Sri Lanka just didn't have any kind of fertilizer, neither organic nor inorganic. Of course that doesn't work, especially not on farm land that had been heavily

Sri Lanka just didn't have any kind of fertilizer, neither organic nor inorganic. Of course that doesn't work, especially not on farm land that had been heavily fertilized in the past. The ground is dead for years because chemical imbalances can only be corrected in the short term with additional fertilizer. Yearly crops don't root deep so after a harvest the next rain will just remove any remaining nutrition, which at that point is heavily one-sided anyway. You have to practice long term crop rotation and you cannot use the field every year. That will obviously use more land. Plants do grow better if you shower them with nitrogen but there still are ways for agricultural growth without regularly poisoning the soil. But yes, that will inevitably mean more expensive food. They just accelerated their plans "slightly" because there was no money for fertilizer, inorganic or not.