不同施肥处理下我国典型农田土壤 对可溶性有机碳的吸附特征.

In order to provide a theoretical basis for the evaluation of carbon sequestration potential, we analyzed the adsorption characteristics and influencing factors of dissolved organic carbon（DOC）in typical farmland soils with different fertilization treatments in China. Four typical farmland soils, namely black soil, gray desert soil, fluvo-aquic soil, and red soil, were selected to apply different fertilizer levels of no fertilizer（CK）, chemical N fertilizer（N）, chemical NP fertilizer（NP）, chemical NPK fertilizer（NPK）, and NPK plus organic manure（NPKM）to determine the DOC adsorption capacities by the equilibrium adsorption method. The results showed that the DOC adsorption capacities of different types of soils at the same equilibrium concentration were very different, and were generally in the order of gray desert soil and red soil>black soil>fluvo-aquic soil.Q max appeared in the order of red soil>gray desert soil>black soil>fluvoaquic soil in various soils. Among them, the adsorption characteristics of each soil type were quite different under different fertilization treatments. The general trend ofQ max in the gray desert soil and fluvo-aquic soil under different fertilization treatments were NPKM>NPK> NP>N>CK and in red soil was NPKM>N>NPK>NP<CK. TheQ max values of the NPKM and NPK treatments were significantly higher than those of the other fertilization treatments in black soil, and that of NPKM was increased by 15.2% compared with that of CK. The K values in the four soils under different fertilization treatments showed that CK treatment was higher than other treatments. The desorption potential （b）values in the four soils increased as the soil organic matter（SOM）increased, and the b value of black soil was far higher than those of the other soil types. Redundancy analysis showed that soil properties could explain 90.61% of the total variation of the DOC adsorption characteristic parameters. The first redundancy factor explained 82.79% of the total variation, which was mainly related to the silt content, clay content, and pH, whereas the second redundancy factor explained 7.82% of the DOC adsorption characteristic parameters, which was mainly related to the SOM content. The results of this paper showed that different types of soils with more clay particles have greater adsorption capacity for DOC, and the same type of soil with more organic matter content has greater adsorption capacity for DOC. [ABSTRACT FROM AUTHOR]