The sustainability of methane catalytic decomposition is significantly enhanced by the production of high-quality value-added carbon products such as carbon nanotubes(CNTs).Understanding the production yields and prop...The sustainability of methane catalytic decomposition is significantly enhanced by the production of high-quality value-added carbon products such as carbon nanotubes(CNTs).Understanding the production yields and properties of CNTs is crucial for improving process feasibility and sustainability.This study employs machine learning technique to develop and analyze predictive models for the carbon yield and mean diameter of CNTs produced through methane catalytic decomposition.Utilizing comprehensive datasets from various experimental studies,the models incorporate variables related to catalyst composition,catalyst preparation,and operational parameters.Both models achieved high predictive accuracy,with R^(2)values exceeding 0.90.Notably,the reduction time during catalyst preparation was found to critically influence carbon yield,evidenced by a permutation importance value of 39.62%.Additionally,the use of Mo as a catalytic metal was observed to significantly reduce the diameter of produced CNTs.These findings highlight the need for future machine learning and simulation studies to include catalyst reduction parameters,thereby enhancing predictive accuracy and deepening process insights.This research provides strategic guidance for optimizing methane catalytic decomposition to produce enhanced CNTs,aligning with sustainability goals.展开更多
This study quantified the impacts of soil organic carbon （SOC） content on the grain yield of crops using a biogeochemical model （DNDC, denitrification-decomposition）. Data on climate, soil properties, and farming ...This study quantified the impacts of soil organic carbon （SOC） content on the grain yield of crops using a biogeochemical model （DNDC, denitrification-decomposition）. Data on climate, soil properties, and farming management regimes of cropping systems were collected from six typical agricultural zones （northeast, north, northwest, mid-south, east and southwest regions of China, respectively） and integrated into a GIS database to support the model runs. According to the model, if the initial SOC content in the cropland was increased by 1 g C kg^-1, the crop yield may be increased by 176 kg ha^-1 for maize in the northeast region, 454 kg ha^-1 for a maize-wheat rotation in the north region, 328 kg ha^-1 for maize in the northwest region, 185 kg ha^-1 for single-rice in the mid-south region, 266 kg ha^-1 for double-rice in east region, and 229 kg ha^-1 for rice and wheat rotation in southwest region. There is a great potential for enhancing the crop yield by improving the SOC content in each region of China.展开更多
Natural ecosystems provide human society with very important products and services. With the rapid increase in population and the over-exploitation of natural resources, humans are continually enhancing the production...Natural ecosystems provide human society with very important products and services. With the rapid increase in population and the over-exploitation of natural resources, humans are continually enhancing the production of some services at the expense of others. This paper estimates changes in ecosystem services, and the relationship between these services in the Guanzhong-Tianshui Economic Region of China. These ecosystem changes are of great significance to the sustainable development of this economic region. The concept of production possibility frontier （PPF） is applied to evaluate the trade-offs and synergy between carbon sequestration, water yield and soil retention. Three land use strategy scenarios - planning, exploitation and protection - are applied to evaluate potential changes in ecosystem services. This study reveals noticeable trade-offs between carbon sequestration, soil retention and water yield, with synergy between carbon sequestration and soil retention. There are synergies between carbon sequestration, water yield and soil retention in the three scenarios. The protection scenario is the most favourable land use strategy for regulating ecosystem service capacity. This scenario results in the highest carbon sequestration, water yield and soil retention. The results could have implications for natural capital and ecosystem services planning, management and land use decision-making.展开更多
The combined use of chemical and organic fertilizers is considered a good method to sustain high crop yield and enhance soil organic carbon （SOC）, but it is still unclear when and to what extent chemical fertilizers...The combined use of chemical and organic fertilizers is considered a good method to sustain high crop yield and enhance soil organic carbon （SOC）, but it is still unclear when and to what extent chemical fertilizers could be replaced by organic fertilizers. We selected a long-term soil fertility experiment in Gongzhuling, Northeast China Plain to examine the temporal dynamics of crop yield and SOC in response to chemical nitrogen, phosphorus, and potassium （NPK） fertilizers and manure, applied both individually and in combination, over the course of three decades （1980-2010）. We aimed to test 1） which fertilizer application is the best for increasing both maize yield and SOC in this region, and 2） whether chemical fertilizers can be replaced by manure to maintain high maize yield and enhance SOC, and if so, when this replacement should be implemented. We observed that NPK fertilizers induced a considerable increase in maize yield in the first 12 years after the initiation of the experiment, but manure addition did not. In the following years, the addition of both NPK fertilizers and manure led to an increase in maize yield. SOC increased considerably in treatments with manure but remained the same or even declined with NPK treatments. The increase in maize yield induced by NPK fertilizers alone declined greatly with increasing SOC, whereas the combination of NPK and manure resulted in high maize yield and a remarkable improvement in SOC stock. Based on these results we suggested that NPK fertilizers could be at least partially replaced by manure to sustain high maize yield after SOC stock has reached 41.96 Mg C ha^-1 in the Northeast China Plain and highly recommend the combined application of chemical fertilizers and manure （i.e., 60 Mg ha^-1）.展开更多
The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the...The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch (Mv). We conducted a 10-year (2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application (22.5 Mg ha^–1). Fertilizer and Mv were applied both individually and in combination (sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80 (by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index (SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input (22.5 Mg ha^–1), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate (with the value higher by 71.6 and 70.1%), whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers (e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.展开更多
The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of s...The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of straw and biochar addition on soil nitrogen form, carbon storage, and super rice yield in cold waterlogged paddy soils. We performed field trials with four treatments including conventional fertilization system （CK）, straw amendment 6 t ha^-1 （S）, biochar amendment 2 t ha^-1 （C1）, and biochar amendment 40 t ha^-1 （C2）. The super japonica rice variety, Shennong 265, was selected as the test Crop. The results showed that the straw and biochar amendments improved total nitrogen and organic carbon content of the soil, reduced N2O emissions, and had little influence on nitrogen retention, nitrogen density, and CO2 emissions. The S and C1 increased NH4^＋-N content, and C2 increased NO3^--N content. Both S and C1 had little influence on soil organic carbon density （SOCD） and C/N ratio. However, C2 greatly increased SOCD and C/N ratio. C1 and C2 significantly improved the soil carbon sequestration （SCS） by 62.9 and 214.0% （P〈0.05）, respectively, while S had no influence on SCS. C1 and C2 maintained the stability of super rice yield, and significantly reduced CH4 emissions, global warming potential （GWP）, and greenhouse gas intensity （GHGI）, whereas S had the opposite and negative effects. In summary, the biochar amendments in cold waterlogged paddy soils of North China increased soil nitrogen and carbon content, improved soil carbon sequestration, and reduced GHG emission without affecting the yield of super rice.展开更多
Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） m...Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） model together with the CENTURT soil model were employed to investigate the effect of low nitrogen （N） input on wheat （Triticum aestivum L.） yield, grain N concentration and soil organic carbon （SOC） in a long-term experiment （19 years） under a wheat-maize （Zea mays L.） rotation at Changping, Beijing, China. There were two treatments including NO （no N application） and N150 （150 kg N ha-1） before wheat and maize planting, with phosphorus （P） and potassium （K） basal fertilizers applied as 75 kg P205 ha-1 and 37.5 kg K^O ha-~, respectively. The DSSAT-CENTURY model was able to satisfactorily simulate measured wheat grain yield and grain N concentration at NO, but could not simulate these parameters at N150, or SOC in either N treatment, Model simulation and field measurement showed that N application （N150） increased wheat yield compared to no N application （NO）. The results indicated that inorganic fertilizer application at the rates used did not maintain crop yield and SOC levels. It is suggested that if the DSSAT is calibrated carefully, it can be a useful tool for assessing and predicting wheat yield, grain N concentration, and SOC trends under wheat-maize cropping systems.展开更多
As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way ...As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated,but remains challenging due to complex processes,time consuming or low yield.Here,taking advantage of recent discovered good solvents for CN,a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles(CN NPs).With simple processes of CN dissolution and precipitation,we can quickly synthesize CN NPs(^40 nm) with a yield of up to 50%,the highest one to the best of our knowledge.As an example of potential applications,the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times.This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.展开更多
In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007....In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007. Some physiological indexes and yield ofD. styracifolium were compared among five nitrogen top-dressing levels （0, 37.5, 75.0, 112.5 and 150.0 kg N. hm-2）. Results showed that the nitrogen top-dressing could significantly increase the contents of chlorophyll, soluble protein, sucrose and nitrogen as well as nitrate reducase activity. However, there were no significant differences in most of these indexes under high nitrogen levels. Consistently, there was no significant difference in yield among nitrogen top-dressing levels of 75 kg N.hm-2, 112.5 kg N. hm-2 and 150 kg N-hm-2. Therefore, the optimum nitrogen top-dressing level ofD. styracifolium was 75 kg N. hm-2.展开更多
The effects of nano-carbon water-retaining fertilizer on yield,quality of tuber mustard,and fertilizer utilization efficiency were studied with the field experiments compared to the local tuber mustard fertilizer with...The effects of nano-carbon water-retaining fertilizer on yield,quality of tuber mustard,and fertilizer utilization efficiency were studied with the field experiments compared to the local tuber mustard fertilizer with equal amount of effective composition. The results showed that the yield of tuber mustard was 50 670-56 496 kg/ha in treatments of nano-carbon water-retaining fertilizer decreasing by 10%-40%,and compared with local tuber mustard fertilizer,the average yield was increased by 94. 8%. The yield increasing rate of tuber mustard was 93. 0%in treatment of nano-carbon water-retaining fertilizer decreasing by 30%. The average fertilizer utilization efficiency of nitrogen and phosphorus was 54% and 39. 7%,respectively,the average increment of fertilizer utilization efficiency was 36% and 37%,respectively compared with local tuber mustard fertilizer. Especially in treatment of reducing nano-carbon water-retaining fertilizer by 30%,the nitrogen and phosphorus fertilizer utilization efficiency was increased by 64% and 56%,respectively. By comprehensive comparison,it was found that nano-carbon waterretaining fertilizer and the treatment of 30% reduction could significantly improve the yield of tuber mustard and fertilizer utilization efficiency,and have popularization and application value in the Three Gorges Reservoir area.展开更多
Northern Guinea Savanna of Nigeria soils are continuously and intensively cultivated, resulting in soil quality degradation, carbon stock depletion, accelerated soil erosion and soil nutrient depletion. Effects of lan...Northern Guinea Savanna of Nigeria soils are continuously and intensively cultivated, resulting in soil quality degradation, carbon stock depletion, accelerated soil erosion and soil nutrient depletion. Effects of land use change on soil carbon stocks (SOC) are of concern regarding greenhouse gas emissions mitigation and sustainable crop production, because there is a need for food sufficiency while conserving the environment. Also, managing soils under intensive use and restoring degraded soils are top priorities for a sustained agronomic production while conserving soil and water resources. Hence, this study;“Tillage, Desmodium intortum, fertilizer rates for carbon stock, soil quality and grain yield in Northern Guinea Savanna” is aimed at devising possible mitigating measures for soil quality degradation, carbon stock depletion and impoverished crop yields using Zea mays as test crop. The study was a Randomized Complete Block Design (RCBD) in split-split plot arrangement with four replicates. The four main tillage and Desmodium intortum combination treatments were: 1) Maize −without Desmodium + Conventional tillage (MC), 2) Maize + Desmodium live-mulch incorporated and relayed + Conservation tillage (MDIC), 3) Maize + Desmodium in no-tillage system (MDNT), 4) Maize + Desmodium in strip tillage (MDST). The main treatment plots were each divided to accommodate four (4) rates of N (60, 80, 100 and 120 kg·ha−1) as sub plots, while the N rate plots were further divided to accommodate three (3) rates of P (6.6, 13.2, and 26.4 kg·ha−1) as sub-subplots. Findings support that Desmodium intercrops with Maize treatments (MDIC, MDNT, and MDST) resulted in increased organic carbon contents in 2013, with MDNT resulting in significantly higher organic carbon content (7.37 g·kg−1 in 2012 and 8.37 g·kg−1 in 2013) than the other treatments. Also, zero tillage practice (MDNT) sequestered significantly higher carbon stock (18.06 t C ha−1), followed by minimum tillage (MDIC) that sequestered 15.99 t C ha−1 than the other treatments. Highest grain yield of 2.61 tha−1 under MDIC and MDNT was followed by MDST and least under MC. Total score of soil quality assessment gave least score values of 13 under MDIC and MDNT;thus best soil quality (SQ1) was ascribed to the minimum tillage with D. intortum intercrop and relayed (MDIC) and Zero tillage with D. intortum (MDNT) treatments. Maize Strip cropped with D. intortum treatment (MDST) was ranked SQ2.展开更多
基金supported by the Agency for Science,Technology and Research(A*STAR),Singapore,under the project Methane Pyrolysis for Hydrogen and Carbon Nanotube Production via Novel Catalytic Membrane Reactor System(No.U2102d2011)。
文摘The sustainability of methane catalytic decomposition is significantly enhanced by the production of high-quality value-added carbon products such as carbon nanotubes(CNTs).Understanding the production yields and properties of CNTs is crucial for improving process feasibility and sustainability.This study employs machine learning technique to develop and analyze predictive models for the carbon yield and mean diameter of CNTs produced through methane catalytic decomposition.Utilizing comprehensive datasets from various experimental studies,the models incorporate variables related to catalyst composition,catalyst preparation,and operational parameters.Both models achieved high predictive accuracy,with R^(2)values exceeding 0.90.Notably,the reduction time during catalyst preparation was found to critically influence carbon yield,evidenced by a permutation importance value of 39.62%.Additionally,the use of Mo as a catalytic metal was observed to significantly reduce the diameter of produced CNTs.These findings highlight the need for future machine learning and simulation studies to include catalyst reduction parameters,thereby enhancing predictive accuracy and deepening process insights.This research provides strategic guidance for optimizing methane catalytic decomposition to produce enhanced CNTs,aligning with sustainability goals.
基金supported by a bilateral scientific cooperation project financed by UGent-BOF,Belgium,and the Ministry of Science and Technology,China (20052)supported by the Non-profit Research Foundation for Agriculture of China (200803036)
文摘This study quantified the impacts of soil organic carbon （SOC） content on the grain yield of crops using a biogeochemical model （DNDC, denitrification-decomposition）. Data on climate, soil properties, and farming management regimes of cropping systems were collected from six typical agricultural zones （northeast, north, northwest, mid-south, east and southwest regions of China, respectively） and integrated into a GIS database to support the model runs. According to the model, if the initial SOC content in the cropland was increased by 1 g C kg^-1, the crop yield may be increased by 176 kg ha^-1 for maize in the northeast region, 454 kg ha^-1 for a maize-wheat rotation in the north region, 328 kg ha^-1 for maize in the northwest region, 185 kg ha^-1 for single-rice in the mid-south region, 266 kg ha^-1 for double-rice in east region, and 229 kg ha^-1 for rice and wheat rotation in southwest region. There is a great potential for enhancing the crop yield by improving the SOC content in each region of China.
基金National Natural Science Foundation of China, No.41371020 Fundamental Research Funds for the Central Universities, No.GK201502010+2 种基金 Innovation Funds of Graduate Programs, Shaanxi Normal University, No.2015CXS045 China Postdoctoral Science Foundation on the 58th Group, No.2015M582706 The Postdoctoral Scientific Research Project Foundation of Shaanxi Province in 2015
文摘Natural ecosystems provide human society with very important products and services. With the rapid increase in population and the over-exploitation of natural resources, humans are continually enhancing the production of some services at the expense of others. This paper estimates changes in ecosystem services, and the relationship between these services in the Guanzhong-Tianshui Economic Region of China. These ecosystem changes are of great significance to the sustainable development of this economic region. The concept of production possibility frontier （PPF） is applied to evaluate the trade-offs and synergy between carbon sequestration, water yield and soil retention. Three land use strategy scenarios - planning, exploitation and protection - are applied to evaluate potential changes in ecosystem services. This study reveals noticeable trade-offs between carbon sequestration, soil retention and water yield, with synergy between carbon sequestration and soil retention. There are synergies between carbon sequestration, water yield and soil retention in the three scenarios. The protection scenario is the most favourable land use strategy for regulating ecosystem service capacity. This scenario results in the highest carbon sequestration, water yield and soil retention. The results could have implications for natural capital and ecosystem services planning, management and land use decision-making.
基金Financial supports are from the National Natural Science Foundation of China(41571298,41620104006)the Special Fund for Agro-scientific Research in the Public Interest,China(201203030,201303126)the National Key Technologies R&D Program of China(2012BAD14B04)
文摘The combined use of chemical and organic fertilizers is considered a good method to sustain high crop yield and enhance soil organic carbon （SOC）, but it is still unclear when and to what extent chemical fertilizers could be replaced by organic fertilizers. We selected a long-term soil fertility experiment in Gongzhuling, Northeast China Plain to examine the temporal dynamics of crop yield and SOC in response to chemical nitrogen, phosphorus, and potassium （NPK） fertilizers and manure, applied both individually and in combination, over the course of three decades （1980-2010）. We aimed to test 1） which fertilizer application is the best for increasing both maize yield and SOC in this region, and 2） whether chemical fertilizers can be replaced by manure to maintain high maize yield and enhance SOC, and if so, when this replacement should be implemented. We observed that NPK fertilizers induced a considerable increase in maize yield in the first 12 years after the initiation of the experiment, but manure addition did not. In the following years, the addition of both NPK fertilizers and manure led to an increase in maize yield. SOC increased considerably in treatments with manure but remained the same or even declined with NPK treatments. The increase in maize yield induced by NPK fertilizers alone declined greatly with increasing SOC, whereas the combination of NPK and manure resulted in high maize yield and a remarkable improvement in SOC stock. Based on these results we suggested that NPK fertilizers could be at least partially replaced by manure to sustain high maize yield after SOC stock has reached 41.96 Mg C ha^-1 in the Northeast China Plain and highly recommend the combined application of chemical fertilizers and manure （i.e., 60 Mg ha^-1）.
基金supported by the earmarked fund for China Agriculture Research System (CARS-22)the Key Special Projects in National Key Research and Development Plan of China (2017YFD0301504 and 2016YFD0300900)+1 种基金the Scientific and Technological Innovation Project in Hunan Academy of Agricultural Sciences, China (2017JC47)the International Plant Nutrition Institute, Canada (IPNI China Program: Hunan-18)
文摘The double-rice cropping system is a very important intensive cropping system for food security in China. There have been few studies of the sustainability of yield and accumulation of soil organic carbon (SOC) in the double-rice cropping system following a partial substitution of chemical fertilizer by Chinese milk vetch (Mv). We conducted a 10-year (2008–2017) field experiment in Nan County, South-Central China, to examine the double-rice productivity and SOC accumulation in a paddy soil in response to different fertilization levels and Mv application (22.5 Mg ha^–1). Fertilizer and Mv were applied both individually and in combination (sole chemical fertilizers, Mv plus 100, 80, 60, 40, and 0% of the recommended dose of chemical fertilizers, labeled as F100, MF100, MF80, MF60, MF40, and MF0, respectively). It was found that the grain yields of double-rice crop in treatments receiving Mv were reduced when the dose of chemical fertilizer was reduced, while the change in SOC stock displayed a double peak curve. The MF100 produced the highest double-rice yield and SOC stock, with the value higher by 13.5 and 26.8% than that in the F100. However, the grain yields increased in the MF80 (by 8.4% compared to the F100), while the SOC stock only increased by 8.4%. Analogous to the change of grain yield, the sustainable yield index (SYI) of double rice were improved significantly in the MF100 and MF80 compared to the F100, while there was a slight increase in the MF60 and MF40. After a certain amount of Mv input (22.5 Mg ha^–1), the carbon sequestration rate was affected by the nutrient input due to the stimulation of microbial biomass. Compared with the MF0, the MF100 and MF40 resulted in a dramatically higher carbon sequestration rate (with the value higher by 71.6 and 70.1%), whereas the MF80 induced a lower carbon sequestration rate with the value lower by 70.1% compared to the MF0. Based on the above results we suggested that Mv could partially replace chemical fertilizers (e.g., 40–60%) to improve or maintain the productivity and sustainability of the double-rice cropping system in South-Central China.
基金supported by the Science and Technology Consulting Program of Chinese Academy of Engineering(2015-XY-25)the Key Technologies R&D Program of China during the 12th Five-Year Plan period(2014BAD02B06-02)+2 种基金the Special Fund for Agro-scientific Research in Public Interest of China(201303095)the Basic Research Foundation of Shenyang Science and Technology Program,China(F16-205-1-38)the Program for Changjiang Scholars and Innovative Research Team in University,China(IRT13079)
文摘The additions of straw and biochar have been suggested to increase soil fertility, carbon sequestration, and crop produc- tivity of agricultural lands. To our knowledge, there is little information on the effects of straw and biochar addition on soil nitrogen form, carbon storage, and super rice yield in cold waterlogged paddy soils. We performed field trials with four treatments including conventional fertilization system （CK）, straw amendment 6 t ha^-1 （S）, biochar amendment 2 t ha^-1 （C1）, and biochar amendment 40 t ha^-1 （C2）. The super japonica rice variety, Shennong 265, was selected as the test Crop. The results showed that the straw and biochar amendments improved total nitrogen and organic carbon content of the soil, reduced N2O emissions, and had little influence on nitrogen retention, nitrogen density, and CO2 emissions. The S and C1 increased NH4^＋-N content, and C2 increased NO3^--N content. Both S and C1 had little influence on soil organic carbon density （SOCD） and C/N ratio. However, C2 greatly increased SOCD and C/N ratio. C1 and C2 significantly improved the soil carbon sequestration （SCS） by 62.9 and 214.0% （P〈0.05）, respectively, while S had no influence on SCS. C1 and C2 maintained the stability of super rice yield, and significantly reduced CH4 emissions, global warming potential （GWP）, and greenhouse gas intensity （GHGI）, whereas S had the opposite and negative effects. In summary, the biochar amendments in cold waterlogged paddy soils of North China increased soil nitrogen and carbon content, improved soil carbon sequestration, and reduced GHG emission without affecting the yield of super rice.
基金funded by the National Natural Science Foundation of China (41471285)the Agricultural Science and Technology Innovation Program (ASTIP) of Chinese Academy of Agricultural Sciences (CAAS-ASTIP-2016AII)+2 种基金the Key Laboratory of Nonpoint Source Pollution Control,Ministry of Agriculture,China (2014-37)the Newton Fund,United Kingdom (BB/N013484/1)the National Key Research and Development Program of China (2016YFD0200601)
文摘Crop modelling can facilitate researchers＇ ability to understand and interpret experimental results, and to diagnose yield gaps. In this paper, the Decision Support Systems for Agrotechnology Transfer 4.6 （DSSAT） model together with the CENTURT soil model were employed to investigate the effect of low nitrogen （N） input on wheat （Triticum aestivum L.） yield, grain N concentration and soil organic carbon （SOC） in a long-term experiment （19 years） under a wheat-maize （Zea mays L.） rotation at Changping, Beijing, China. There were two treatments including NO （no N application） and N150 （150 kg N ha-1） before wheat and maize planting, with phosphorus （P） and potassium （K） basal fertilizers applied as 75 kg P205 ha-1 and 37.5 kg K^O ha-~, respectively. The DSSAT-CENTURY model was able to satisfactorily simulate measured wheat grain yield and grain N concentration at NO, but could not simulate these parameters at N150, or SOC in either N treatment, Model simulation and field measurement showed that N application （N150） increased wheat yield compared to no N application （NO）. The results indicated that inorganic fertilizer application at the rates used did not maintain crop yield and SOC levels. It is suggested that if the DSSAT is calibrated carefully, it can be a useful tool for assessing and predicting wheat yield, grain N concentration, and SOC trends under wheat-maize cropping systems.
基金financially supported in part by the National Natural Science Foundation of China(Nos.21775018,21675022)the Natural Science Foundation of Jiangsu Province(Nos.BK20160028,BK20170084)+1 种基金the Open Funds of the State Key Laboratory of Electroanalytical Chemistry(No.SKLEAC201909)the Fundamental Research Funds for the Central Universities。
文摘As an emerging 2D conjugated material,graphitic carbon nitride(CN) has attracted great research attention as important catalytic medium for transforming solar energy.Nanostructure modulation of CN is an effective way to improve catalytic activities and has been extensively investigated,but remains challenging due to complex processes,time consuming or low yield.Here,taking advantage of recent discovered good solvents for CN,a nanoprecipitation approach using poor solvents is proposed for preparation of CN nanoparticles(CN NPs).With simple processes of CN dissolution and precipitation,we can quickly synthesize CN NPs(^40 nm) with a yield of up to 50%,the highest one to the best of our knowledge.As an example of potential applications,the as-prepared CN NPs were applied to photocatalytic degradation of dyes with an evident boosted performance up to 2.5 times.This work would open a new way for batch preparation of nanostructured CN and pave its large-scale industrial applications.
基金Supported by Scientifi c Research Foundation of Guangxi University (x061106)
文摘In order to research effects of the nitrogen top-dressing levels on carbon-nitrogen metabolism and yield of Desmodium styracifolium, a field experiment was conducted on the research farm of Guangxi University in 2007. Some physiological indexes and yield ofD. styracifolium were compared among five nitrogen top-dressing levels （0, 37.5, 75.0, 112.5 and 150.0 kg N. hm-2）. Results showed that the nitrogen top-dressing could significantly increase the contents of chlorophyll, soluble protein, sucrose and nitrogen as well as nitrate reducase activity. However, there were no significant differences in most of these indexes under high nitrogen levels. Consistently, there was no significant difference in yield among nitrogen top-dressing levels of 75 kg N.hm-2, 112.5 kg N. hm-2 and 150 kg N-hm-2. Therefore, the optimum nitrogen top-dressing level ofD. styracifolium was 75 kg N. hm-2.
基金Supported by National Natural Science Foundation of China(41571303)Scientific Research Project for Follow-up Work of the Three Gorges(2015HXKY2-4-2)
文摘The effects of nano-carbon water-retaining fertilizer on yield,quality of tuber mustard,and fertilizer utilization efficiency were studied with the field experiments compared to the local tuber mustard fertilizer with equal amount of effective composition. The results showed that the yield of tuber mustard was 50 670-56 496 kg/ha in treatments of nano-carbon water-retaining fertilizer decreasing by 10%-40%,and compared with local tuber mustard fertilizer,the average yield was increased by 94. 8%. The yield increasing rate of tuber mustard was 93. 0%in treatment of nano-carbon water-retaining fertilizer decreasing by 30%. The average fertilizer utilization efficiency of nitrogen and phosphorus was 54% and 39. 7%,respectively,the average increment of fertilizer utilization efficiency was 36% and 37%,respectively compared with local tuber mustard fertilizer. Especially in treatment of reducing nano-carbon water-retaining fertilizer by 30%,the nitrogen and phosphorus fertilizer utilization efficiency was increased by 64% and 56%,respectively. By comprehensive comparison,it was found that nano-carbon waterretaining fertilizer and the treatment of 30% reduction could significantly improve the yield of tuber mustard and fertilizer utilization efficiency,and have popularization and application value in the Three Gorges Reservoir area.
文摘Northern Guinea Savanna of Nigeria soils are continuously and intensively cultivated, resulting in soil quality degradation, carbon stock depletion, accelerated soil erosion and soil nutrient depletion. Effects of land use change on soil carbon stocks (SOC) are of concern regarding greenhouse gas emissions mitigation and sustainable crop production, because there is a need for food sufficiency while conserving the environment. Also, managing soils under intensive use and restoring degraded soils are top priorities for a sustained agronomic production while conserving soil and water resources. Hence, this study;“Tillage, Desmodium intortum, fertilizer rates for carbon stock, soil quality and grain yield in Northern Guinea Savanna” is aimed at devising possible mitigating measures for soil quality degradation, carbon stock depletion and impoverished crop yields using Zea mays as test crop. The study was a Randomized Complete Block Design (RCBD) in split-split plot arrangement with four replicates. The four main tillage and Desmodium intortum combination treatments were: 1) Maize −without Desmodium + Conventional tillage (MC), 2) Maize + Desmodium live-mulch incorporated and relayed + Conservation tillage (MDIC), 3) Maize + Desmodium in no-tillage system (MDNT), 4) Maize + Desmodium in strip tillage (MDST). The main treatment plots were each divided to accommodate four (4) rates of N (60, 80, 100 and 120 kg·ha−1) as sub plots, while the N rate plots were further divided to accommodate three (3) rates of P (6.6, 13.2, and 26.4 kg·ha−1) as sub-subplots. Findings support that Desmodium intercrops with Maize treatments (MDIC, MDNT, and MDST) resulted in increased organic carbon contents in 2013, with MDNT resulting in significantly higher organic carbon content (7.37 g·kg−1 in 2012 and 8.37 g·kg−1 in 2013) than the other treatments. Also, zero tillage practice (MDNT) sequestered significantly higher carbon stock (18.06 t C ha−1), followed by minimum tillage (MDIC) that sequestered 15.99 t C ha−1 than the other treatments. Highest grain yield of 2.61 tha−1 under MDIC and MDNT was followed by MDST and least under MC. Total score of soil quality assessment gave least score values of 13 under MDIC and MDNT;thus best soil quality (SQ1) was ascribed to the minimum tillage with D. intortum intercrop and relayed (MDIC) and Zero tillage with D. intortum (MDNT) treatments. Maize Strip cropped with D. intortum treatment (MDST) was ranked SQ2.
文摘为了解红树林凋落物生产动态与碳、氮归还,评估不同红树群落的固碳潜能,以淇澳岛红树林优势物种无瓣海桑(Sonneratia apetala)与秋茄(Kandelia obovata)为研究对象,于2022—2023年采用凋落物收集框法,监测了淇澳岛外来物种无瓣海桑和本土秋茄的凋落物产量月动态以及凋落物各组分(枝、叶、花、果)碳、氮储量的季节动态,探究物种、林龄和潮位对凋落物产量月变化的影响,通过凋落物产量与碳、氮含量估算淇澳岛地上碳、氮储量,对沿海城市红树林生态恢复管理具有重要意义。结果表明:凋落物月总产量在不同月份、林龄和潮位影响下差异显著(P<0.001),4个样地年均总产量为1503.1 g·m^(-2),各样地年总产量表现为低潮位20年生无瓣海桑>高潮位20年生无瓣海桑>秋茄>低潮位14年生无瓣海桑。其中,主要以落叶(总占比为45.6%)为主,其次为落果(35.8%),落花最少(1.5%)。凋落量高峰集中在夏季和秋季,月均温与凋落物总产量呈显著正相关(P<0.01)。凋落物碳、氮含量与储量在不同组分和季节间存在显著差异,碳、氮含量分别为400.9~477.2、8.9~26.3 mg·g^(-1);无瓣海桑年总碳、氮储量分别为1096.5 g C·m^(-2)、66.14 g N·m^(-2),分别是秋茄的1.9和3.7倍,碳、氮归还能力较高。凋落物产量及碳氮储量受多种因素影响,碳、氮收支的估算应考虑季节与组分的作用。
