关键词: 干扰度, 有机碳, 易氧化碳, 矿化速率, 累积矿化量, 生物结皮盖度

Abstract: Study on correlation between soil physicochemical properties and fungiderived glomalinrelated soil proteins (GRSP) at different depths is helpful to uncover the role of soil fungi in different soil layers. In this paper, 360 soil samples were collected at 5 different depths (0-100 cm) in Songnen Plain cropland to analyze EE-GRSP, T-GRSP, 11 soil  physicochemical properties and their correlations. EE-GRSP and T-GRSP contents were 0.74 and 6.0 mg·g^-1 in surface soil, respectively, and both declined significantly with the soil depth. Moreover, the deeper soil layer (40-100 cm) stored 41.2%-62.8% of SOC, total N, total P, total K, alkalinehydrolyzed N, available P, and available K at 0-100 cm. Soil pH, bulk density, moisture and electrical conductivity also had obvious vertical variation patterns. Obvious differences of correlations between various soil physicochemical properties and GRSP (EE-GRSP, T-GRSP) were found in different soil layers. A significant correlation between SOC and GRSP was found in all layers, and a significant correlation between soil pH and GRSP (P<0.01) was found in all layers except 0-20 cm. Most physicochemical properties  were correlated with EE-GRSP and T-GRSP at 60-80 cm and 20-60 cm, while few of such correlations were found in surface soil. These results showed that GRSP may have better correlations with soil properties in deeper soil layers than in surface layer, which affects the function of GRSP in regulating soil nutrients at different depths. We propose that planting deeprooting ligneous plants that have symbiosis with soil fungi is helpful for bioremediation of nutrientaffluent deeper soil layers.

Key words: biocrust coverage, SOC, cumulative mineralization amount, disturbance intensity, SEOC, mineralization rate.