Abstract
Aim: To evaluate the physical and hydrological properties of different graded coir pith and composted coir pith (CPOM) following the Keen-Raczkowski box and Brunauer-Emmett-Teller (BET) analysis. Methodology: The coir pith was collected and composted by PITH PLUS (Pleurotus-sajor-caju). Thereafter, the coir pith and composted coir pith were segregated into different groups based on the size of the particles as 1.0 mm (1000 microns), 0.5 mm (500 microns), and 0.25 mm (250 microns). Based on particle size, the hydrological properties of coir pith and composted coir pith were determined. The physical and hydrological properties were estimated by the Keen-Raczkowski box method and Brunauer-Emmett-Teller analysis. Results: Different graded coir pith and composted coir pith of size 0.25 mm showed the highest bulk density (0.60 and 0.48 g cm-3), followed by 0.5 mm size coir pith and composted coir pith, respectively. The highest particle density (0.18 and 0.19 g cm-3) was registered in 1.0 mm coir pith and composted coir pith whereas the lowest particle density was observed in 0.25 mm size coir pith (0.15 g cm-3). The water-holding capacity (817.93 % and 806.97 %) and water in air-dry substrate (25.03 % and 36.094 %) was high in 0.25 mm coir pith and composted coir pith. Interpretation: A 0.25 mm grade of coir pith and composted coir pith showed highest water holding and retaining capacity due to a greater number of small particles being compactly arranged and holding more surface area, and innumerable micropores than other graded particles. Key words: BET analysis, Coir pith, Composted coir pith, Water holding capacity