Soil respiration characteristics in different land uses and response of soil organic carbon to biochar addition in high-latitude agricultural area

Abstract

The farmland tillage practices changed the soil chemical properties, which also impacted the soil respiration (R s ) process and the soil carbon conservation. Originally, the farmland in northeast China had high soil carbon content, which was decreased in the recent decades due to the tillage practices. To better understand the R s dynamics in different land use types and its relationship with soil carbon loss, soil samples at two layers (0-15 and 15-30 cm) were analyzed for organic carbon (OC), total nitrogen (TN), total phosphorus (TP), total carbon (TC), available nitrogen (AN), available phosphorus (AP), soil particle size distribution, as well as the R s rate. The R s rate of the paddy land was 0.22 (at 0-15 cm) and 3.01 (at 15-30 cm) times of the upland. The average concentrations of OC and clay content in cultivated areas were much lower than in non-cultivated areas. The partial least squares analysis suggested that the TC and TN were significantly related to the R s process in cultivated soils. The upland soil was further used to test soil CO2 emission response at different biochar addition levels during 70-days incubation. The measurement in the limited incubation period demonstrated that the addition of biochar improved the soil C content because it had high concentration of pyrogenic C, which was resistant to mineralization. The analysis showed that biochar addition can promote soil OC by mitigating carbon dioxide (CO2) emission. The biochar addition achieved the best performance for the soil carbon conservation in high-latitude agricultural area due to the originally high carbon content.

Influence of Biochar on Soil Nutrient Transformations, Nutrient Leaching, and Crop Yield

“…30,43 Sigua et al, 44 conducted a field study using switch grass biochar and found that biochar additions to soil increased N immobilization and decreased in total inorganic N in soils due to the wide C/N ratio of switch grass. These researchers also observed a significant increase in cumulative and net CO 2 flux implying biochar simulated switchgrass mineralization and accelerated decomposition of resident soil C. 44,45 Similar observations such as increased respiration rates have been recently reported; 46 however, Jones et al 47 suggested that increased CO 2 evolution immediately after biochar addition partially originates from the emission of inorganic C within biochar itself. Therefore, the influence of biochar on N immobilization needs to be further studied with focus on the bioavailable C and direct effects of biochar on microbial activity.…”

Microbial nitrification, denitrification and respiration in the leached cinnamon soil of the upper basin of Miyun Reservoir

“…4 ). However, denitrification rate tended to be more consistency with respiration rate than that of nitrification rate, for the reason that denitrification and respiration are carbon consuming processes 23 63 64 65 . As can be seen from Fig.…”

The location- and scale- specific correlation between temperature and soil carbon sequestration across the globe

“…Between 52°N and 40°S, SOC was negatively correlated with soil temperature. In these tropical and temperate zones, the soil temperature is the dominant limiting factor of soil respiration (SOC decomposition), whereas photosynthesis (SOC formation) is limited by multiple factors, including light, CO 2 concentration, water stress, and nutrient availability (Stockmann et al, 2013;Ouyang et al, 2016). Therefore, this negative correlation was most likely due to the increasing soil respiration with increasing temperature (Post et al, 1982;Ghosh et al, 2016).…”