Rice Straw Decomposition by Woodlice (Isopoda, Oniscidea) and Millipedes (Myriapoda, Diplopoda) in the Soils of Kalmykia in a Laboratory Experiment

Rice crop residues are one of the recalcitrant agricultural wastes in arid conditions. A laboratory experiment was conducted to decompose rice straw with woodlice and millipedes living in the dry steppes of Kalmykia in Russia. Five individuals of two species of woodlice (Armadillidium vulgare and Protracheoniscus kryszanovskii) or two species of millipedes (Brachydesmus assimilis and Cylindroiulus sp.) were placed in microcosms with soil and 2.5 g of rice straw. The straw mass significantly decreased for all species, by approximately 50% on average for the 4 months of the experiment. The content of organic matter in the soil before and after the experiment did not change significantly, which suggests that the selected species of woodlice and millipedes can consume and, thus utilize, rice straw, at least under experimental conditions.