Assuming you have many coconut trees, I suggest
Drip irrigation in coconut
Root zone of coconut for moisture absorption is concentrated in a circular area of 200 cm radius around the base of coconut tree up to a depth of 100 cm. Irrigating coconut trees by a set of four drippers set equidistant in a circle 100 cm away from the base of the tree and discharging water at the rate of 30 l/h for 2.5 h with a irrigation frequency of 8 days can maximize the wetting area of soils in the effective root zone of coconut increses yield and also mulch the base to avoid water evaporation.
The manuring depends on the age of the plant. For complete details please refer the coconut Board website.