Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management...Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management for the establishment of grass-legume mixtures.However,a common concern is that intensive tillage may alter soil characteristics,leading to losses in soil organic carbon(SOC).We investigated the plant community composition,SOC,soil microbial biomass carbon(MBC),soil enzyme activities,and soil properties in long-term perennial grass-legume mixtures under two different tillage intensities(once and twice)as well as in a fenced grassland(FG).The establishment of grass-legume mixtures increased plant species diversity and plant community coverage,compared with FG.Compared with once tilled grassland(OTG),twice tilled grassland(TTG)enhanced the coverage of high-quality leguminous forage species by 380.3%.Grass-legume mixtures with historical tillage decreased SOC and dissolved organic carbon(DOC)concentrations,whereas soil MBC concentrations in OTG and TTG increased by 16.0%and 16.4%,respectively,compared with FG.TTG significantly decreased the activity of N-acetyl-β-D-glucosaminidase(NAG)by 72.3%,whereas soil enzymeβ-glucosidase(βG)in OTG and TTG increased by 55.9%and 27.3%,respectively,compared with FG.Correlation analysis indicated a close association of the increase in MBC andβG activities with the rapid decline in SOC.This result suggested that MBC was a key driving factor in soil carbon storage dynamics,potentially accelerating soil carbon cycling and facilitating biogeochemical cycling.The establishment of grass-legume mixtures effectively improves forage quality and boosts plant diversity,thereby facilitating the restoration of degraded grasslands.Although tillage assists in establishing legume-grass mixtures by controlling weeds,it accelerates microbial activity and organic carbon decomposition.Our findings provide a foundation for understanding the process and effectiveness of restoration management in degraded grasslands.展开更多
The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectr...The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectroscopy(DOSY)is a non-selective and non-invasive method capable of achieving pseudo-separation and structure assignments of individual compounds from biomass mixtures by providing diffusion coefficients(D)of the components.However,the conventional 1H DOSY NMR is limited by crowded resonances when analyzing complex mixtures containing similar chemical structure resulting in similar coefficient.Herein we describe the application of an advanced diffusion NMR method,Pure Shift Yielded by CHirp Excitation DOSY(PSYCHE-iDOSY),which can record high-resolution signal diffusion spectra efficiently separating compounds in model and genuine mixture samples from cellulose,hemicellulose and lignin.Complicated sets of isomers(D-glucose/D-fructose/D-mannose and 1,2-/1,5-pentadiol),homologous compounds(ethylene glycol and 1,2-propylene glycol),model compounds of lignin,and a genuine reaction system(furfuryl alcohol hydrogenolysis with ring opening)were successfully separated in the diffusion dimension.The results show that the ultrahigh-resolution DOSY technique is capable of detecting and pseudo-separating the mixture components of C_(5)/C_(6) sugar conversion products and its derivative hydrogenation/hydrogenolysis from lignocellulose biomass.展开更多
Spruce (Picea Smithiana) is an evergreen tree and distributed through the temperate Himalaya at the elevation of 2000 - 3500 m. Natural regeneration of spruce (Picea smithiana) is generally slow and almost negligible ...Spruce (Picea Smithiana) is an evergreen tree and distributed through the temperate Himalaya at the elevation of 2000 - 3500 m. Natural regeneration of spruce (Picea smithiana) is generally slow and almost negligible due to a number of factors e.g. presence of un decomposed raw humus on forest floor low germinative capacity of seed and infrequent good seed years. In order to supplement natural regeneration through artificial means, nursery raising assumes significance. The present study aimed at optimizing the root trainer container size and the potting mixture ingredients and their proportion for the production of quality nursery stock of Picea smithiana. Nine combinations of potting mixture ingredients (Forest Soil, Garden Soil, Sand, FYM and Lake weed) were tested in various ratios for the optimization of potty mixture in different root trainer sizes. Simultaneously, three different volumes (150cc, 250cc and 300cc) of root trainers were tested for suitability of container size. Chemical and physical analysis of potting mixture ingredients was carried out for better understanding of nutrient status. The best seedling growth at seven month age in terms of height (5.53 cm), Collar diameter (1.57 mm), fresh shoot weight (0.34 g), dry shoot weight (0.10 g), fresh root weight (0.27 g) , dry root weight (0.03 g), root shoot ratio(2:52), and total fresh biomass (0.61 g) were observed when seedlings were raised in root trainer container size (300cc) filled with potting mixture of (M8) Soil:Sand:FYM (1:1:2) and the lowest growth parameters were observed in root trainer container size (150cc) filled with forest soil only. Plantable quality seedlings can be recovered within a period of 7 months using potting mixture of Soil, Sand and FYM (1:1:2) and Soil, Sand and Lake weed (1:1:2) ratios in root trainer container size 300cc.展开更多
This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment,...This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650℃. Average sample heating rates in the reactor were 21, 30 and 54 ℃/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650℃ and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has sig- nificant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650℃ produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.展开更多
基金funded by the National Natural Science Foundation of China(32271776,32171616)the Special Sichuan Postdoctoral Research Projectsthe National Natural Science Foundation of Sichuan Province,China(2024NSFSC0309,2022NSFSC1769,2022NSFSC0110).
文摘Perennial grass-legume mixtures have been extensively used to restore degraded grasslands,increasing grassland productivity and forage quality.Tillage is crucial for seedbed preparation and sustainable weed management for the establishment of grass-legume mixtures.However,a common concern is that intensive tillage may alter soil characteristics,leading to losses in soil organic carbon(SOC).We investigated the plant community composition,SOC,soil microbial biomass carbon(MBC),soil enzyme activities,and soil properties in long-term perennial grass-legume mixtures under two different tillage intensities(once and twice)as well as in a fenced grassland(FG).The establishment of grass-legume mixtures increased plant species diversity and plant community coverage,compared with FG.Compared with once tilled grassland(OTG),twice tilled grassland(TTG)enhanced the coverage of high-quality leguminous forage species by 380.3%.Grass-legume mixtures with historical tillage decreased SOC and dissolved organic carbon(DOC)concentrations,whereas soil MBC concentrations in OTG and TTG increased by 16.0%and 16.4%,respectively,compared with FG.TTG significantly decreased the activity of N-acetyl-β-D-glucosaminidase(NAG)by 72.3%,whereas soil enzymeβ-glucosidase(βG)in OTG and TTG increased by 55.9%and 27.3%,respectively,compared with FG.Correlation analysis indicated a close association of the increase in MBC andβG activities with the rapid decline in SOC.This result suggested that MBC was a key driving factor in soil carbon storage dynamics,potentially accelerating soil carbon cycling and facilitating biogeochemical cycling.The establishment of grass-legume mixtures effectively improves forage quality and boosts plant diversity,thereby facilitating the restoration of degraded grasslands.Although tillage assists in establishing legume-grass mixtures by controlling weeds,it accelerates microbial activity and organic carbon decomposition.Our findings provide a foundation for understanding the process and effectiveness of restoration management in degraded grasslands.
基金The authors thank for National Natural Science Foundation of China(22075308)for financial support。
文摘The component analysis and structure characterization of complex mixtures of biomass conversion remain a challenging work.Hence,developing effective and easy to use techniques is necessary.Diffusion-ordered NMR spectroscopy(DOSY)is a non-selective and non-invasive method capable of achieving pseudo-separation and structure assignments of individual compounds from biomass mixtures by providing diffusion coefficients(D)of the components.However,the conventional 1H DOSY NMR is limited by crowded resonances when analyzing complex mixtures containing similar chemical structure resulting in similar coefficient.Herein we describe the application of an advanced diffusion NMR method,Pure Shift Yielded by CHirp Excitation DOSY(PSYCHE-iDOSY),which can record high-resolution signal diffusion spectra efficiently separating compounds in model and genuine mixture samples from cellulose,hemicellulose and lignin.Complicated sets of isomers(D-glucose/D-fructose/D-mannose and 1,2-/1,5-pentadiol),homologous compounds(ethylene glycol and 1,2-propylene glycol),model compounds of lignin,and a genuine reaction system(furfuryl alcohol hydrogenolysis with ring opening)were successfully separated in the diffusion dimension.The results show that the ultrahigh-resolution DOSY technique is capable of detecting and pseudo-separating the mixture components of C_(5)/C_(6) sugar conversion products and its derivative hydrogenation/hydrogenolysis from lignocellulose biomass.
文摘Spruce (Picea Smithiana) is an evergreen tree and distributed through the temperate Himalaya at the elevation of 2000 - 3500 m. Natural regeneration of spruce (Picea smithiana) is generally slow and almost negligible due to a number of factors e.g. presence of un decomposed raw humus on forest floor low germinative capacity of seed and infrequent good seed years. In order to supplement natural regeneration through artificial means, nursery raising assumes significance. The present study aimed at optimizing the root trainer container size and the potting mixture ingredients and their proportion for the production of quality nursery stock of Picea smithiana. Nine combinations of potting mixture ingredients (Forest Soil, Garden Soil, Sand, FYM and Lake weed) were tested in various ratios for the optimization of potty mixture in different root trainer sizes. Simultaneously, three different volumes (150cc, 250cc and 300cc) of root trainers were tested for suitability of container size. Chemical and physical analysis of potting mixture ingredients was carried out for better understanding of nutrient status. The best seedling growth at seven month age in terms of height (5.53 cm), Collar diameter (1.57 mm), fresh shoot weight (0.34 g), dry shoot weight (0.10 g), fresh root weight (0.27 g) , dry root weight (0.03 g), root shoot ratio(2:52), and total fresh biomass (0.61 g) were observed when seedlings were raised in root trainer container size (300cc) filled with potting mixture of (M8) Soil:Sand:FYM (1:1:2) and the lowest growth parameters were observed in root trainer container size (150cc) filled with forest soil only. Plantable quality seedlings can be recovered within a period of 7 months using potting mixture of Soil, Sand and FYM (1:1:2) and Soil, Sand and Lake weed (1:1:2) ratios in root trainer container size 300cc.
基金Partially financed by the Ministry of Education,Science and Technological Development of the Republic of Serbia
文摘This paper describes an experimental investigation of pyrolysis of woody biomass mixture. The mixture consists of oak, beech, fir, cherry, walnut and linden wood chips with equal mass fractions. During the experiment, the sample mass inside the reactor was 10 g with a particle diameter of 5-10 mm. The sample in the reactor was heated in the temperature range of 24-650℃. Average sample heating rates in the reactor were 21, 30 and 54 ℃/min. The sample mass before, during and after pyrolysis was determined using a digital scale. Experimental results of the sample mass change indicate that the highest yield of pyrolytic gas was achieved at the temperature slightly above 650℃ and ranged from 77 to 85%, while char yield ranged from 15 to 23%. Heating rate has sig- nificant influence on the pyrolytic gas and char yields. It was determined that higher pyrolysis temperatures and heating rates induce higher yields of pyrolytic gas, while the char mass reduces. Condensation of pyrolytic gas at the end of the pyrolysis process at 650℃ produced 2.4-2.72 g of liquid phase. The results obtained represent a starting basis for determining material and heat balance of pyrolysis process as well as woody biomass pyrolysis equipment.
