Use of carbonized rice hulls as a horticultural amendment for an organic soil

Abstract

The advance of plasticulture requires the optimization of horticultural substrate. Organic soils, as peat, are used internationally as a standard material in the making of substrates. However, they can show limitations, as high water retention and low pH values. This study measures the alterations in chemical and physical properties of peat "lagoa-dos-patos" (Viamão/RS) brought about by the addition of rice hulls. The pure materials (T and C) and the mixtures (1TIC, 2T1C, 1T2C) were characterized by bulk density, particle size, dry matter, total porosity, air space, water holding capacity, pH value, soluble salt contents, cations exchange capacity and organic carbon content. Carbonized rice hulls improved the peat "lagoa-dos-patos". In the proportion 2:1 (C:T) the pH value was increased from 4.2 to 5.3. The particle size of the mixtures was more homogeneous, the air space was increased and the residual water holding was reduced.