Soil incubation data of fencing and grazing grasslands with 13C-glucose addition

This dataset records basic soil information and its corresponding incubation data from five pairs of fencing and grazing sites in the temperate grasslands of northern China.Ten soil samples were collected from fencing and grazing sites of five temperate grasslands on the Inner Mongolian Plateau, China, in August 2021. Before sampling, plant aboveground biomass was measured using the dry weighing method. At each site, soils of the top 20 cm layer were sampled and passed through a 2 mm sieve to remove visible stones, roots, and other plant debris. After homogenization, soil texture, SOC, and MBC content were measured. All soil samples were stored at -20 °C until the incubation experiment started.During the incubation, 13C-labeled glucose addition treatments were performed and four replicates were conducted. Soil samples equivalent to 20 g air-dried soil were added to 250 ml mason jars. All soils were incubated in the dark at 25 °C and a relative humidity of 60% for 102 days. After a 7-day pre-incubation, 13C-labeled glucose (99 atom% 13C) was added at a dose of 0.4 mg C g-1 soil. On days 1, 3, 6, 12, 19, 34, 47, 78, and 102 of the incubation, each jar was flushed with CO2-free air for 3 minutes. After that, the CO2 emission rate was measured using an infrared gas analyzer (Li-8100A; Li-COR, USA) within 3 minutes from the headspace. The average cumulative respiration of the four replicates and its standard error (SE) are provided in the dataset. After the last gas measurement, soils were destructively harvested and stored at -80℃ for the subsequent soil carbon (C) pools measurements.The chloroform-fumigation-extraction method was used to determine MBC contents. The POC and MAOC content were assessed through the particle size fractionation method. 13C isotope of each C pool were analyzed using an Isotope Ratio Mass Spectrometer (Delta V Advantage, ThermoFisher Scientific, America). Further, the contributions of glucose-derived C to the MBC, POC, and MAOC pools were calculated using the isotopic mixing model.