Design and development of a two wheel tractor driven coconut fertilizer applicator

Coconut (Cocos nucifera L.) is a perennial tree crop with about 60 years of economic life span. Decreasing soil fertility over several decades due to inadequate replenishment of the exhausted nutrients is a major problem affecting coconut production. The annual yield from a single tree can be increased from 50-70 nuts up to 100-125 nuts by proper application of fertilizer. There is no efficient method to apply fertilizer to coconut estates at present except manual application, which is laborious. The general objective of this research was to investigate an efficient method for applying fertilizer to coconut estates. After investigating physical properties of raw materials and their influences on the performance of fertilizer application, a two-wheel tractor driven granular fertilizer applicator was developed. Main components of the applicator are hopper, opposite-direction screw, two sets of furrow openers, fertilizer tubes, and a furrow closer. Power transmission from the engine to the applicator was done by chain and sprockets. The applicator was designed to apply 5 kg of fertilizer mixture per palm at an optimum speed of 1.1 km/h. The fertilizer applicator was evaluated in a coconut estate and received satisfactory results. It performed at a fertilizer feeding capacity of 0.45 ha/hr with 72.7 % efficiency. Compared to the traditional method, this fertilizer applicator could save 96.5 % of time and 94 % of the cost of fertilizer application per hectare. COCOS Vol. 20: 27-37 (2013