Effects of Soil Compaction and Tillage Practices on Carbon Dioxide Efflux in Northeast China: Evidence from an Incubation Study

Abstract

Limited information is available for how soil compaction affects carbon dioxide (CO 2 ) efflux under different tillage systems. To improve understanding of the effects of compaction and tillage on soil CO 2 efflux, an incubation study consisting of no tillage (NT), moldboard plow (MP), and ridge tillage (RT) was conducted to explore the relationships between CO 2 efflux and bulk density, as well as pore size distribution under different levels of bulk densities, and the thresholds of bulk density and the volume of pore size above which CO 2 efflux were affected in northeast China. Results showed that there was a significantly negative correlation (r = -0.990, p<0.05; r = -0.986, p<0.05; and r = -0.992, p<0.01, respectively, for NT, MP, and RT) between CO 2 efflux and bulk density, whereas the correlation was significantly positive (r ranges from 0.75 to 0.85, p<0.05 for each tillage practice under bulk densities of 1.0-1.6 g/cm 3 ) for the volume of small macropores (30-100 µm). The critical value of bulk density for impeding CO 2 efflux was more produced in 1.6 g/cm 3 and the volume of small macropores affected CO 2 efflux variation greatly. Ridge tillage is a better tillage practice for impeding soil CO 2 efflux than no tillage, as evidenced by the lesser volume of small macropores.

Vertical Variation in Temperature Sensitivity of Soil Organic Carbon Mineralization in Changbai Mountain, China: A Microcosm Study

“…Previous research has reported a substantial decrease in organic carbon mineralization with rising BD. This decline could be attributed to the increase in soil compaction, leading to reduced soil aeration and consequently inhibiting the decomposition of soil organic carbon by microorganisms [55,56], consistent with our research. Nevertheless, the effect of BD on carbon mineralization is largely reflected in soil aeration and its impact may vary under the combined influence of different soil textures and water conditions [57].…”

Earthworm Positively Influences Large Macropores Under Extreme Drought Conditions and Conservation Tillage in a Chinese Mollisol

“…This means that earthworm activity has no effect on the small macropores. The reason for this situation was the partial destruction of large macropores by soil disturbance, resulting in the formation of a greater volume of small macropores under MP (Chen et al, 2016). Kay and van den Bygaart (2002) found that shifts from conventional to conservation tillage usually led to a reduction in the volume of small macropores.…”