The effect size and composition of bioreactor from sand and compost to porosity purpose of bed

Abstract

Abstract Population increase causes the need for products from plants also to increase and land is decreasing so a certain process of intensification in agriculture needed. One of them is by making a plant bioreactor that can be modelled as a fixed bed composed of compost and grains of sand. The spatial structure of the bioreactor can facilitate the presence of water, air, root system development, and life systems of various soil biota so that they are create a mechanism of production on demand for plants. The purpose of this study was to obtain the effect of bed variations on the porosity parameter (ԑ). Bed variations consist of size variations (not sifted; 4 - 2 mm; 2 - 1 mm; 1 mm - 500 μm; 500 - 250 μm and 250 - 125 μm) and composition variations (100:0; 25:75; 50:50; 75:25 and 0:100) from compost and sand. The results showed that the addition of compost would increase the porosity of bed. The bed consisting of sand and compost with a ratio of 25:75 with a diameter of 4 - 2 mm is a good composition to increase porosity of bed with a porosity value around (ԑ) of 0.7.