Northeast Institute of Geography and Agroecology, Chinese Academy Of Sciences
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Soil carbon sequestration and crop yield in response to application of chemical fertilizer combined with cattle manure to an artificially eroded Phaeozem
No full textOrganic manure application is a feasible approach to alleviate the deterioration of soil erosion on soil organic carbon (SOC). However, to what extent manure application can restore carbon contents in SOC fractions in the eroded Phaeozems remains unknown. A 5-year field experiment was conducted in an artificially eroded Phaeozem with up to 30cm of topsoil being removed. Chemical fertiliser, or chemical fertiliser plus cattle manure was applied. The contents of SOC were 23.6, 21.6 and 15.1gC kg(-1) soil for non-soil removal control, 10 and 30cm of topsoil removal, respectively. Compared with the chemical fertiliser-only treatment, the chemical fertiliser plus manure application markedly increased SOC contents by 30-45% and C sequestration rates by 7.1-9.0-fold, especially in the fraction of 53-250 m particulate organic carbon. However, with manure applied, SOC content in the fraction of mineral associated organic carbon in the 30cm topsoil-removed soil was 2.9g kg(-1), 14.7% less than control (3.4g kg(-1)). The combination of chemical fertliser and manure application effectively restored SOC in the eroded Phaeozems mainly through increasing the size of 53-250 m particulate organic C fraction, but did not improve the SOC stability in severely eroded Phaeozems
Snow Depth Inversion Using the Localized HUT Model Based on FY-3B MWRI Data in the Farmland of Heilongjiang Province, China
No full textSnow depth parameter inversion in the farmland using passive microwave remote sensing is of great significance to the agricultural production in Northeast China. Firstly, the Helsinki University of Technology (HUT) snow emission model was validated in the farmland based on microwave radiation imager (MWRI) onboard FengYun-3B satellite (FY-3B). The results showed that there was a big difference between the brightness temperature of HUT model simulation and MWRI for 18.7 GHz horizontal polarization (18.7 H) and 36.5 GHz horizontal polarization (36.5 H). To improve HUT model, the empirical parameter in the model was localized. Then the localized HUT (LHUT) model was built, where the extinction coefficient was calculated by the new extinction coefficient formula. Next, LHUT model was validated based on MWRI data and compared with HUT model. The results showed that LHUT underestimates slightly the brightness temperature with 0.91 and 4.19 K for 18.7 and 36.5 H respectively, and LHUT is superior to HUT model. Finally, the genetic algorithm (GA) was used to invert snow depth based on LHUT. The results showed that snow depth was underestimated with 6.79 cm based on LHUT. The inverted snow depth based on LHUT model is in better agreement with the measured snow depth
The fate of soybean residue -carbon links to changes of bacterial community composition in Mollisols differing in soil organic carbon
No full textQuantifying residue carbon (C) incorporation into soil organic C (SOC) fractions, and underpinning microbial community in the decomposition process of crop residues are essential for improving SOC management in agricultural systems. However, the fate of residue-C and associated responses of microbial communities remain unclear in Mollisols in north-eastern China, where SOC varies geographically. A 150-day incubation experiment was conducted with C-13-labelled soybean residue (4%) amended into two Mollisols differing in SOC (SOC-poor and SOC-rich soils). The C-13 abundances in SOC fractions and the CO2-C efflux from soil were determined, and bacterial community composition was analyzed with MiSeq sequencing. The amounts of residue-C incorporated into the coarse particulate organic C (POC), fine POC and mineral-associated C (MOC) fractions were 4.5-, 4.3- and 2.4-fold higher in the SOC-rich soil than in the SOC-poor soil, respectively. Residue amendment led to negative SOC priming before Day 50 but positive priming thereafter. The primed CO2 per unit of native SOC was greater in the SOC-poor soil than in the SOC-rich soil. This indicates that the contributions of residue-C to the POC and MOC fractions were greater in the SOC-rich soil while residue amendment had stronger priming effect in the SOC-poor soil, stimulating the C exchange rate between fresh and native SOC. A principal coordinates analysis (PCoA) showed that the shift of bacterial community structure in response to residue amendment varied between the two soils. Genera Verrucosispora, Xanthomonadales and Steroidobacter Were mainly enriched in the residue-amended SOC-poor soil while Anaerolineaceae_uncultured was dordinant in the SOC-rich soil. The canonical correspondence analysis (CCA) revealed that the relative abundance of the bacterial operational taxonomic unit (OTU) among residue treatments was significantly associated with soil characteristics, especially C content in coar(se) POC and MOC fractions (p < 0.01), implying that the shift of bacterial community composition in response to residue amendment contributes to the sequestration of residue-C in SOC fractions. (C) 2017 Elsevier Ltd. All rights reserved
A facile approach for surface alteration of Pseudomonas putida I3 by supplying K2SO4 into growth medium: Enhanced removal of Pb(II) from aqueous solution
No full textA new sight of obtaining a high efficient biosorbent by supplying specific salts into bacterial growth medium was investigated in this study for Pb(II). Among a series of salts including Na2SO4, Na2S2O3, KCl, and K2SO4, the highest Pb(II) removal efficiency was observed by psychrotrophilic Pseudomonas putida I3 grown in the presence of 30 g/L K2SO4 (KSI3-30) with biosorption capacity of 62.89 mg/g under cold condition (15 degrees C), which was increased by 42.35% as compared to control (without any additive, RI3). This stimulation effect was ascribed to the increase of potassium and sulfur containing groups on KSI3-30 surface via metabolic dependent ways. The probable mechanism for Pb(II) adsorption was ion-exchange and chemical complexation. The thermal and kinetic data well fitted to Langmuir adsorption model and pseudo-second order and intraparticle diffusion kinetic model. Good recyclability and effectively dealing with real wastewater suggested KSI3-30 was a promising biosorbent for Pb-contaminated wastewater treatment. (C) 2017 Elsevier Ltd. All rights reserved
