Physico-Chemical and Physical Properties of some Substrates Used in Horticulture

Abstract

This study was carried out in 2001 using some organic (peat moss, peat, sawdust) and inorganic (perlite, pumice, creek sand) substrates. pH, electrical conductivity, cation exchange capacity, carbonates, organic matter, particle size distribution, bulk density, water retention characteristics and pore size distribution of substrates were determined. The amount of water retained at the low tensions (< pF 2.52) in pumice, sawdust, peat moss, perlite, peat and creek sand was 62.6, 59.2, 57.1, 53.7, 53.0 and 28.9 based on % of volume, respectively. However, among the organic-organic, inorganic-inorganic and organicinorganic mixes, those values were highest in peat : sawdust (60.0 %), perlite : creek sand (40.1 %) and sawdust : perlite (57.2 %). Among the organic, inorganic, organic-organic, inorganic-inorganic and organicinorganic mixes, the highest amount of macropores (> 100 μm) supply aeration were 56.9% (sawdust), 60.2% (pumice), 56.0% (peat : sawdust), 34.4 % (perlite:creek sand), 52.6 % (sawdust : perlite). The lowest bulk density of substrates were 0.086 g cm–3 (peat moss), 0.118 g cm–3 (perlite), 0.121 g cm–3 (peat moss : sawdust), 0.325 g cm–3 (perlite : pumice) and 0.099 g cm–3 (peat moss : perlite), respectively. pH values of substrates varied from 5.1 (peat moss and peat) to 7.6 (pumice). The highest electrical conductivity, cation exchange capacity, carbonates and organic matter values of substrates were 1.065 dS m–1 (peat), 206.4 cmol kg–1 (peat moss), 0.75 % (pumice) and 95.0 % (peat moss), respectively.