Lasting effect of soil warming on organic matter decomposition depends on tillage practices

Abstract

a b s t r a c tGlobal warming accelerates soil organic matter (SOM) decomposition with strong feedback to atmospheric CO 2 . Such an effect should be especially important for no-till agricultural practices, where SOM accumulates in the topsoil as compared with conventional tillage. We incubated soil samples (0e5 cm) at three temperature levels (15, 21 and 27 C) from long-term till and no-till systems that were in situ warmed and non-warmed to assess the temperature sensitivity of CO 2 efflux, labile organic carbon and extracellular enzyme activities. Thermal adaptation to prolonged warming was observed resulting in a lasting effect on SOM decomposition. On average, 26, 14 and 12% more CO 2 was emitted at each incubation temperature from the warmed soils compared to the non-warmed soils. The Q 10 value was lower for the warmed than the non-warmed soils. Soil microbial biomass C and dissolved organic C declined with warming. The activities of three extracellular enzymes, b-glucosidase, chitinase, and sulfatase, were higher under warming and no-till as compared to non-warmed and tilled soil. We concluded that the increased SOM decomposition due to the stimulation of microorganisms by warming was long-lasting. Predictions of C accumulation in the topsoil by no-till farming should be taken with caution, as this C pool is especially vulnerable to global warming.

Large‐scale soil organic carbon mapping based on multivariate modelling: The case of grasslands on the Loess Plateau

“…Increased temperatures promote soil warming, and warming significantly decreases SOC contents (Fang, Smith, Moncrieff, & Smith, ; Qi et al, ). Increased levels of soil respiration and mineralized C associated with increasing temperature may be responsible for SOC consumption (Allison, Wallenstein, & Bradford, ; Hou, Ouyang, Maxim, Wilson, & Kuzyakov, ; Lefèvre et al, ; Wu, Dijkstra, Koch, Peñuelas, & Hungate, ).…”

Short-Term Response of the Soil Microbial Abundances and Enzyme Activities to Experimental Warming in a Boreal Peatland in Northeast China

“…We previously found that increasing temperature significantly hastens the cumulative CO 2 emission from the decomposition of peat soil MBC and DOC by an incubation experiment [44]. Rinnan et al [45] and Hou et al [46] also found that soil warming negatively affects the soil MBC. One possible explanation for this result is that the cell reserves and labile substrates for microbes are depleted under warming [46].…”

“…Rinnan et al [45] and Hou et al [46] also found that soil warming negatively affects the soil MBC. One possible explanation for this result is that the cell reserves and labile substrates for microbes are depleted under warming [46]. The results of our study indicated that warming exerted no evident effect on soil TC, which is consistent with the results of Chen et al [47].…”

Soil organic carbon temperature sensitivity of different soil types and land use systems in the Brazilian semi‐arid region

“…Q 10 is the proportional change in soil respiration for a 10°C increase in temperature and may be used as an important approach to enhance our understanding of SOC dynamics. It allows the evaluation of different aspects, such as the role of the SOM lability, the temperature impact on the sequence in which organic material compounds are decomposed (Conant et al., ), the activity of soil microorganisms (Hou et al., ) and of soil texture (Wei et al., ). Our findings for the Q 10 index are consistent with studies that have addressed similar topics (Conant et al., ; Plante et al., ; Xu et al., ), where the most studied situations gave larger values of Q 10 for more resistant soil carbon.…”

“…More studies on SOC dynamics in semi‐arid conditions are needed, as temperatures above 30°C (INMET, ) are relatively common and can easily reach 40°C at the soil surface (Hamdi et al., ). Therefore, among the several variables that regulate the SOC decomposition, temperature has certainly gained attention (Conant et al., ; Cui et al., ; Hou, Ouyang, Maxim, Wilson, & Kuzyakov, ; Plante et al., ), and this theme has been approached in several aspects, such as the role of substrate availability (Hamdi et al., ); different soil types and tillage systems (Birge et al., ; Hou et al., ; Zhang, Li, Yang, & Sun, ), moisture levels (Richardson et al., ), and the responses of different SOM fractions (Carrillo, Pendall, Morgan, & Newcomb, ; Fang, Smith, Moncrieff, & Smith, ; Hou et al., ; Plante et al., ; Xu, Zhou, Ruan, Luo, & Wang, ).…”