Details

Autor(en) / Beteiligte

• Ghosh, Avijit
• Das, Anshuman
• Das, Debarup
• Ray, Prasenjit
• Bhattacharyya, Ranjan
• Biswas, Dipak Ranjan
• Biswas, Siddhartha Sankar

Titel

Contrasting land use systems and soil organic matter quality and temperature sensitivity in North Eastern India

Ist Teil von

• Soil & tillage research, 2020-05, Vol.199, p.104573, Article 104573

Ort / Verlag

Elsevier B.V

Erscheinungsjahr

2020

Quelle

Alma/SFX Local Collection

Beschreibungen/Notizen

• [Display omitted] •Polyphenol content increased with soil depth in natural and managed land uses.•Higher Q10 for natural ecosystem than managed land uses.•Greater Q10 for sub-surface soil C than surface soil.•Microbial decomposability of SOC had no significant relation with Q10.•MBC/SOC and activation energy were suitable predictors of Q10. Although quality of soil organic matter (SOM) plays an important role in carbon (C) cycling of cropland and natural ecosystems under the changing climatic scenario, its impact on temperature sensitivity (Q10) is seldom studied together in surface and sub-surface soils of natural and managed ecosystems situated at different altitudes. So, a study was conducted by collecting soil samples from 0 to 15 and 15 to 30 cm depths under natural forest (NF), mulberry plantation (MP), rice-mustard (RM) and rice-fallow (RF) systems of north-eastern region of India to find out the quality and Q10 of SOM under varying land uses at different altitudes. Soils were incubated at 15, 25 and 35 °C for 52 days to estimate C decay rates (k), intermediate (after 24 day) Q10(24), final Q10, activation energy (Ea) and SOM quality parameters. Results revealed that cumulative CO2 emission was the lowest under NF at 15 °C, while it was the lowest under RF at 35 °C. The proportion of C-mineralized to total soil organic C (SOC) was the highest under RF (situated at higher altitude) and the lowest under NF system (situated at lower altitude). The SOC of the NF system had the highest Q10 value and higher recalcitrant C. The Q10 values of NF were ∼16 and 44% higher in the 0–15 and 15−30 cm soil layers, respectively than managed ecosystems. The ratios of microbial biomass C (MBC) to SOC and Ea were well correlated (P < 0.05) with Q10. The Q10(24) of surface soil was higher in managed ecosystems, but Q10 was higher for sub-surface C in the natural ecosystem. Hence, protecting natural ecosystems is very important to mitigate climate change. We found MBC/SOC and Ea to be better predictors of SOM quality and these should be included in soil C models for predicting C dynamics. Path analysis and PCA analysis revealed that soil variants, SOM quality and C pools significantly affected Q10 but climatic variables had nonsignificant impact on Q10.