Influence of particle size on physical and chemical properties of coconut coir dust as container medium

The influence of particle size (diameter between < 0.125 mm and > 2 mm) on the physical, physico-chemical and chemical properties of a coconut coir dust from Mexico was studied. Particle size significantly affected the physical properties, especially the air-water relationships. Air content increased and water-holding capacity (total and readily available) decreased with increasing particle diameter. The easily-available water content did not reveal a clear pattern of variation, showing the largest value in the fraction 0.125-0.25 nun. Particle size equivalent to 0.5 mm brought about an important and highly significant change in the physical properties studied. Coconut coir dust particle size also affected the physico-chemical and chemical characteristics, but to a lesser degree. Both the electrical conductivity and the available macro- and micro-element concentrations were significantly higher in the smaller size ranges, the largest values being obtained in the finest particle size fraction (< 0.125 mm).