Soil arylsulfatase (ARS) is an important enzyme that controls the acquisition of organic sulfur and thus the soil sulfur cycling. However, compared to those enzymes that involved in the acquisition of organic carbon, nitrogen, and phosphorus, ARS activity and its regulations have rarely been investigated.
To determine the major controls on soil ARS activity, researchers from the Institute of Subtropical Agriculture (ISA) of Chinese Academy of Sciences investigated ARS activity in cropland, grassland, shrubland, secondary forest and plantation forest underlain by three lithology types, i.e., limestone, dolomite and clasolite in a region of southwest China.

The team found that soil ARS activity increased from cropland through to forest following post-agriculture succession, and was significantly lower in clasolite than in dolomite or limestone.

Among 14 studied soil variables, five variables (i.e. soil pH, exchangeable calcium, organic carbon, clay and silt) showed significant relationships with ARS activity, and these relationships were non-linear.

Path analysis further showed that the activity of soil ARS was most controlled by soil pH and soil texture, but soil calcium and organic carbon only had indirect or spurious effects on ARS activity.

"Differing from most previous studies that used linear analysis, our results highlight that non-linear analysis is a better way for exploring the controlling factors of soil ARS activity, and we suggest that at the regional scale, soil pH and soil texture may be the most sensitive indicators of soil ARS activity.” said CHEN Hao, an associate professor at ISA and first author on the paper.

The work was funded by the National Key Research and Development Program of China (2016YFC0502404), the National Natural Science Foundation of China (31872691, 41877094), Natural Science Foundation of Guangxi Province of China (2017GXNSFAA198038), and the Chinese Academy of Sciences through its "Light of West China" Program to Hao Chen.

The study entitled “Controls on soil arylsulfatase activity at a regional scale” has been published online in European Journal of Soil Biology. This article is available for download at https://doi.org/10.1016/j.ejsobi.2018.11.001.

Contact: LI Dejun

E-mail: dejunli@isa.ac.cn

Institute of Subtropical Agriculture, Chinese Academy of Sciences