Digital soil morphometrics of krotovinas in a deep Alfisol derived from loess in Shenyang, China

Abstract

Krotovinas, burrows of small mammals, occur widely in the soils of the steppes. The distribution and effect of krotovinas on soil organic carbon (SOC) stocks were studied in a deep profile (450cm) at an archaeological site of the Palaeolithic period at Shenyang Agricultural University of China. It was found krotovinas occurred at all depths, and there was variation in their distribution and size. The density of krotovinas increased with depth, and was the highest (10/m2) at 250cm depth. The average area of krotovinas' sections in most part of the profile ranged from 100 to 160cm2. Krotovinas covered an area of 7 to 17% of the profile wall. Average SOC concentration in the krotovinas was 5.3g/kg, whereas it was 4.5g/kg in the surrounding soil matrix. SOC stocks at 100 to 450cm accounted for 72% of total SOC stocks at 0 to 450cm depth. Total SOC stock in the whole profile (0 to 450cm) was 295t/ha considering the presence of krotovinas, whereas it was 274t/ha when the krotovinas were excluded. This study shows how krotovinas can be quantified, and that krotovinas can affect SOC concentration and change patterns of SOC distribution. The amount of SOC stored in deep soils should be taken into consideration for evaluating SOC stocks.