Plant Soil Environ., 2020, 66(11):598-605 | DOI: 10.17221/426/2020-PSE

Active carbon pool-size is enhanced by long-term manure applicationOriginal Paper

Meng Wei¹, Aijun Zhang¹, Zhonghou Tang¹, Peng Zhao¹, Hong Pan², Hui Wang², Quangang Yang², Yanhong Lou^*,2, Yuping Zhuge^*,2

¹ Xuzhou Institute of Agricultural Sciences of the Xuhuai District of Jiangsu Province/Xuzhou Sweet Potato Research Center of Jiangsu Province, Xuzhou, P.R. China

² National Engineering Laboratory for Efficient Utilisation of Soil and Fertiliser Resources, College of Resources and Environment, Shandong Agricultural University, Taian, P.R. China

We studied the dynamics of soil organic carbon (SOC)-pool mineralisation in agricultural soil. A laboratory incubation experiment was conducted using the soil from a long-term experiment involving the following fertilisation regimes: no fertilisation (CK); mineral (NPK); organic (M), and combined organic-inorganic fertilisers (MNPK). SOC mineralisation rate decreased as follows: MNPK > M > NPK > CK. Cumulative SOC mineralisation (C_m) ranged between 730.15 and 3 022.09 mg/kg in CK and MNPK, respectively; 8.81% (CK) to 20.45% (MNPK) of initial SOC was mineralised after a 360-day incubation. Soil C_m values were significantly higher under NPK, M, and MNPK compared to those under the CK treatment. Dynamic variation in C_m with incubation time fitted a double exponential model. Active carbon pools accounted for 2.06-6.51% of total SOC and the average mean resistant time (MRT₁) was 28.76 days, whereas slow carbon pools accounted for 93.49-97.94% of SOC, with an average MRT₂ of 8.53 years. The active carbon pool in fertilised soils was larger than in CK; furthermore, it was larger in M- and MNPK- than under NPK-treated plots. SOC decomposed more easily in long-term fertilised plots than in non-fertilised plots.

Keywords: macronutrient; land use management; decomposition; fluvo-aquic soil; long-term fertilisation; organic carbon mineralisation

Published: November 30, 2020  Show citation