Characterization of compost grades originated by dry fractionation for various particle size of compost produced by some agriculture residues

Composts are varied in their properties because of the variation in the raw materials and composting management. The current study aims to apply the dry fractionation for three end-product composts of rice straw, bagasse and cotton stalks. In addition to the un-fractioned compost (G0), the fractionation distributed particles into 6 grades in particle size, namely, G1 > 2.8, G2= 2 –2.8, G3= 1.7-2, G4= 1-1.7, G5= 0.6-1, G6= 0.43-0.60 and G7 < 0.43 mm. The compost grades were characterized for agrochemicals and biological properties depending on various particle size. Composted rice straw (SC) displayed the smallest particle size (0.69 mm) with the most homogeneity (2.19 mm) followed by compost of bagasse (BC) and cotton stalk (CC) with particle size 1.15 and 1.26 mm and homogeneity 2.64 and 2.68 mm, respectively. Except bulk densities or pH, the general overall trend indicated significant decreases in electrical conductivity, organic matter, C/N ratio, nitrogen and microbial activity as particle size decrease. The fractions of finest particle size recorded an improvement in the germination present and embryo radicals of cress seeds as compared coarser fractions. From the research that has been conducted, it is possible to conclude that dry fractionation is an appropriate simple technique can be implemented to reform custom-made composts improve and/or overcome less maturity, salinity, orientation, agrochemicals variation and/or financial issues encountered with stakeholders in the field of waste recycling.