Soil organic carbon mobility in equatorial podzols: soil column experiments

Transfer of organic carbon from topsoil horizons to deeper horizons and to the water table is still little documented, in particular in equatorial environments, despite the high primary productivity of the evergreen forest. Due to its complexing capacity, organic carbon also plays a key role in the transfer of metals in the soil profile and, therefore, in pedogenesis and for metal mobility. Here we focus on equatorial podzols, which are known to play an important role in carbon cycling. We carried out soil column experiments using soil material and percolating solution sampled in an Amazonian podzol area in order to better constrain the conditions of the transfer of organic carbon at depth. The dissolved organic matter (DOM) produced in the topsoil was not able to percolate through the clayey, kaolinitic material from the deep horizons and was retained in it. When it previously percolated through the Bh material, there was production of fulvic-like, protein-like compounds and small carboxylic acids able to percolate through the clayey material and increase the mobility of Al, Fe and Si. Podzolic processes in the Bh can, therefore, produce a DOM likely to be transferred to the deep water table, playing a role in the carbon balances at the profile scale and, owing to its complexing capacity, playing a role in deep horizon pedogenesis and weathering. The order of magnitude of carbon concentration in the solution percolating at depth was around 1.5–2.5 mg L−1. Our findings reveal a fundamental mechanism that favors the formation of very thick kaolinitic saprolites.

Selective Catalysis for the Reductive Amination of Furfural Towards Furfurylamine by the Graphene-Co-Shelled Cobalt Nanoparticles

<p>Amines with functional groups are widely used in the manufacture of pharmaceuticals, agricultural chemicals, polymers, and surfactants; so far, amines are mostly produced via petrochemical routes, which <a></a><a>motivates the sustainable production of amines from renewable resources</a>, such as biomass. Unfortunately, the reductive amination of biomass-derived platforms is now suffering from challenges, e.g. poor <a></a><a>selectivity </a>and carbon balances, because of the restriction of homogenous catalyst. For this reason, we developed an eco-friendly, simplified, and highly effective procedure for the preparation of non-toxic heterogeneous catalyst based on the earth-abundant metals (i.e., cobalt), whose catalytic activity on furfural or other biomass-derived platforms were proved to be broadly available. The corresponding conversion rate and few of side products were also determined so as to optimized the reaction conditions, suggesting that the prepared cobalt-supported catalyst enables easy substitution of –NH₂moiety towards functionalized and structurally diverse molecules, even under very mild industrially viable and scalable conditions. More surprisingly, the cobalt-supported catalyst could also be expediently recycled by magnetic bar and still remained the excellent catalytic activity after reusing up to eight times; on another hands, the gram-scale reductive amination catalyzed by the same catalyst exhibited the similar yield of target products in comparison to its smaller scale, which was comparable to the reported heterogeneous noble-based catalysts. And also, results from a series of analytic technologies involving XRD, XPS, TEM/Mapping and <i>in-suit</i> FTIR revealed that the structural features of catalyst are closely in relation to its catalytic mechanisms; in simple terms, <a></a><a>the outer graphitic shell is activated by the electronic interaction between the inner </a><a></a><a>metallic </a>nanoparticles and the carbon layer as well as the induced charge redistribution. In conclusion, this newly developed catalysts enable the synthesis of amines from biomass-derived platforms with satisfied selectivity and carbon balance, providing a cost-effective and sustainable access to the widely application of reductive amination.</p>

Selective Catalysis for the Reductive Amination of Furfural Towards Furfurylamine by the Graphene-Co-Shelled Cobalt Nanoparticles

<p>Amines with functional groups are widely used in the manufacture of pharmaceuticals, agricultural chemicals, polymers, and surfactants; so far, amines are mostly produced via petrochemical routes, which <a></a><a>motivates the sustainable production of amines from renewable resources</a>, such as biomass. Unfortunately, the reductive amination of biomass-derived platforms is now suffering from challenges, e.g. poor <a></a><a>selectivity </a>and carbon balances, because of the restriction of homogenous catalyst. For this reason, we developed an eco-friendly, simplified, and highly effective procedure for the preparation of non-toxic heterogeneous catalyst based on the earth-abundant metals (i.e., cobalt), whose catalytic activity on furfural or other biomass-derived platforms were proved to be broadly available. The corresponding conversion rate and few of side products were also determined so as to optimized the reaction conditions, suggesting that the prepared cobalt-supported catalyst enables easy substitution of –NH₂moiety towards functionalized and structurally diverse molecules, even under very mild industrially viable and scalable conditions. More surprisingly, the cobalt-supported catalyst could also be expediently recycled by magnetic bar and still remained the excellent catalytic activity after reusing up to eight times; on another hands, the gram-scale reductive amination catalyzed by the same catalyst exhibited the similar yield of target products in comparison to its smaller scale, which was comparable to the reported heterogeneous noble-based catalysts. And also, results from a series of analytic technologies involving XRD, XPS, TEM/Mapping and <i>in-suit</i> FTIR revealed that the structural features of catalyst are closely in relation to its catalytic mechanisms; in simple terms, <a></a><a>the outer graphitic shell is activated by the electronic interaction between the inner </a><a></a><a>metallic </a>nanoparticles and the carbon layer as well as the induced charge redistribution. In conclusion, this newly developed catalysts enable the synthesis of amines from biomass-derived platforms with satisfied selectivity and carbon balance, providing a cost-effective and sustainable access to the widely application of reductive amination.</p>

Monitoring and Evaluating Nature-Based Solutions Implementation in Urban Areas by Means of Earth Observation

Climate change influences the vulnerability of urban populations worldwide. To improve their adaptive capacity, the implementation of nature-based solutions (NBS) in urban areas has been identified as an appropriate action, giving urban planning and development an important role towards climate change adaptation/mitigation and risk management and resilience. However, the importance of extensively applying NBS is still underestimated, especially regarding its potential to induce significantly positive environmental and socioeconomic impacts across cities. Concerning environmental impacts, monitoring and evaluation is an important step of NBS management, where earth observation (EO) can contribute. EO is known for providing valuable disaggregated data to assess the modifications caused by NBS implementation in terms of land cover, whereas the potential of EO to uncover the role of NBS in urban metabolism modifications (e.g., energy, water, and carbon fluxes and balances) still remains underexplored. This study reviews the EO potential in the monitoring and evaluation of NBS implementation in cities, indicating that satellite observations combined with data from complementary sources may provide an evidence-based approach in terms of NBS adaptive management. EO-based tools can be applied to assess NBS’ impacts on urban energy, water, and carbon balances, further improving our understanding of urban systems dynamics and supporting sustainable urbanization.

Effect of straw retention on carbon footprint under different cropping sequences in Northeast China

Inappropriate farm management practices can lead to increased agricultural inputs and changes in atmospheric greenhouse gas (GHG) emissions, impacting climate change. This study assessed the potential of straw retention to mitigate the negative environmental impact of different cropping systems on the Songnen Plain using the life cycle assessment (LCA) method combined with field survey data. Straw retention (STR) and straw removal (STM) treatments were established in continuous corn (CC) and corn-soybean rotation (CS) systems in a split-plot experiment. The effects of straw retention on the carbon footprint (CF) of cropland under different cropping systems were compared. The CF under CC was 2434.0–2706.9 kg CO 2 ha -1 yr -1 , 49.3%–57.3% higher than that under CS. Nitrogen fertilizer produced the most CO 2 , accounting for 66.2%-80.4% of the CF. The carbon balances of the CC and CS systems with STR were positive, with annual carbon sequestrations of 9632.5 and 2715.9 kg CO 2 ha -1 yr -1 , respectively. The carbon balances of the CC and CS systems with STM was negative, with annual carbon sequestrations of -3589.2 and -3006.2 kg CO 2 ha -1 yr -1 , respectively. This study demonstrates that STR under CC cultivation is an environmentally friendly practice for agricultural production, can help achieve high-yield and low-carbon production in rainfed cropland, and can support the sustainable development of grain production in Northeast China.

Soil organic carbon mobility in equatorial podzols: soil column experiments

Transfer of organic carbon from topsoil horizons to deeper horizons and to water table is still little documented, in particular in equatorial environments despite the high primary productivity of the evergreen forest. Due to its complexing capacity, organic carbon also plays a key role in the transfer of metals in the soil profile and therefore in pedogenesis and for metal mobility. We were interested in equatorial podzols, which are known to play a significant role in carbon cycling. We carried out soil column experiments using soil material and percolating solution sampled in an Amazonian podzol area. The dissolved organic matter (DOM) produced in the topsoil was not able to percolate through the clayey, kaolinitic material from the deep horizons and was retained in it. When it previously percolated through the Bh material, there was production of fulvic-like, protein-like compounds and small carboxylic acids able to percolate through the clayey material and increasing the mobility of Al, Fe and Si. Podzolic processes in the Bh can therefore produce a DOM likely to be transferred to the deep water table, playing a role in the carbon balances at the profile scale, and owing to its complexing capacity, playing a role in deep horizon pedogenesis and weathering. The order of magnitude of carbon concentration in the solution percolating in depth was around 1.5–2.5 mg L−1.

Effects of Leucaena leucocephala supplementation to basal hay on Energy and Protein metabolism in West African. Dwarf sheep

Energy and protein utilization and quantitative retention of protein, fat and energy was investigated with twelve castrated West African Dwarf (WAD) sheep averaging (23.0 h 2.4 kg BW) in nitrogen and energy balance trials. Dried leaves of Leucaena leucocephala were offered as supplement at two levels 25% (diet 2) and 50% (diet 3) of dry matter intake (DM1), replacing hay in the basal hay diet. The basal hay diet without supplementation was the control. Measurements were performed by means of nitrogen and carbon balances and with the use of indirect calorimetry The digestibility and utilization of protein were influenced (P<0.05) by supplementation. Metabolisability of energy (ME/ GE) was on the average 42.9 (SEM 4.3)% being significantly (P<0.05) different among treatments. Diet 2 had a higher (P<0.05) retained protein (9.6 g/d) compared with the control diet and hence a superior (P<0.05) protein utilization than the control and diet 3, respectively. It was concluded that Leucaena leuccocephala improved protein utilization and retention in WAD sheep.