Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multipl...Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multiple stages of development before yielding a final product. The final biofertilizer is used by legumes-protein-rich crops in symbiosis with rhizobia to enable biological nitrogen fixation increasing natural soil fertility. This study aims to determine the optimal formulation of a rhizobial biofertilizer to improve the performance of soybean (Glycine max L. cv. Docko). To this end, soybean seeds obtained from IRAD were coated with different formulations derived from locally sourced materials. Palm kernel oil was used as an adhesive in one group, while corn powder served as an adhesive in another. The coated seeds were then sown in the field. The results indicate that the combination of pigeon pea powder + sugarcane molasses, with palm kernel oil as an adhesive, produced the best nodulation (nitrogen fixation). This formulation also led to significant improvements in growth (+350%) and total nitrogen content (+1100%) compared to the bacterial broth inoculum control (B0) (P ≤ 0.01). These findings represent a significant advancement in improving nitrogen-fixing bacterial inoculants and enhancing soil fertility for the sustainable cultivation of soybeans in this tropical soil.展开更多
Biodiversity experiments have shown that soil organic carbon(SOC)is not only a function of plant diversity,but is also closely related to the nitrogen(N)-fixing plants.However,the effect of N-fixing trees on SOC chemi...Biodiversity experiments have shown that soil organic carbon(SOC)is not only a function of plant diversity,but is also closely related to the nitrogen(N)-fixing plants.However,the effect of N-fixing trees on SOC chemical stability is still little known,especially with the compounding effects of tree species diversity.An experimental field manipulation was established in subtropical plantations of southern China to explore the impacts of tree species richness(i.e.,one,two,four and six tree species)and with/without N-fixing trees on SOC chemical stability,as indicated by the ratio of easily oxidized organic carbon to SOC(EOC/SOC).Plant-derived C components in terms of hydrolysable plant lipids and lignin phenols were isolated from soils for evaluating their relative contributions to SOC chemical stability.The results showed that N-fixing tree species rather than tree species richness had a significant effect on EOC/SOC.Hydrolysable plant lipids and lignin phenols were negatively correlated with EOC/SOC,while hydrolysable plant lipids contributed more to EOC/SOC than lignin phenols,especially in the occurrence of N-fixing trees.The presence of N-fixing tree species led to an increase in soil N availability and a decrease in fungal abundance,promoting the selective retention of certain key components of hydrolysable plant lipids,thus enhancing SOC chemical stability.These findings underpin the crucial role of N-fixing trees in shaping SOC chemical stability,and therefore,preferential selection of N-fixing tree species in mixed plantations is an appropriate silvicultural strategy to improve SOC chemical stability in subtropical plantations.展开更多
We report on the effects of forest management practices of understory removal and N-fixing species（Cassia alata） addition on soil CO2 fluxes in an Eucalyptus urophylla plantation（EUp）,Acacia crassicarpa plantation...We report on the effects of forest management practices of understory removal and N-fixing species（Cassia alata） addition on soil CO2 fluxes in an Eucalyptus urophylla plantation（EUp）,Acacia crassicarpa plantation（ACp）,10-species-mixed plantation（Tp）,and 30-species-mixed plantation（THp） using the static chamber method in southern China.Four forest management treatments,including（1） understory removal（UR）;（2） C.alata addition（CA）;（3） understory removal and replacement with C.alata（UR＋CA）;and（4） control without any disturbances（CK）,were applied in the above four forest plantations with three replications for each treatment.The results showed that soil CO2 fluxes rates remained at a high level during the rainy season（from April to September）,followed by a rapid decrease after October reaching a minimum in February.Soil CO2 fluxes were significantly higher（P 〈 0.01） in EUp（132.6 mg/（m2.hr）） and ACp（139.8 mg/（m2.hr）） than in Tp（94.0 mg/（m2.hr）） and THp（102.9 mg/（m2.hr））.Soil CO2 fluxes in UR and CA were significantly higher（P 〈 0.01） among the four treatments,with values of 105.7,120.4,133.6 and 112.2 mg/（m2.hr） for UR＋CA,UR,CA and CK,respectively.Soil CO2 fluxes were positively correlated with soil temperature（P 〈 0.01）,soil moisture（P 〈 0.01）,NO3？-N（P 〈 0.05）,and litterfall（P 〈 0.01）,indicating that all these factors might be important controlling variables for soil CO2 fluxes.This study sheds some light on our understanding of soil CO2 flux dynamics in forest plantations under various management practices.展开更多
Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated mi...Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood.In this study,an investigation was conducted to determine C,N,and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5(1.5-Y),7(7-Y),10(10-Y),and 14(14-Y)years and at an unmined site(the control group)in Jiangxi Province,China.Longitudinal tailing delamination at each site was investigated in 0–15(layer 1)and 15–30(layer 2)cm tailing layers.During the abandoned duration of REE tailings,C and P in layer 1 continued to recover from 1.62 to 8.51 g kg^(-1) and from 0.71 to 1.94 g kg^(-1),respectively;N losses of 0.60 and 0.22 g kg^(-1) occurred at the 1.5-Y and 10-Y sites,while N in layer 1 slightly increased at the 14-Y site.Mesorhizobium,Methylosinus,Bradyrhizobium,Pseudomonas,and Azospirillum were dominant bacteria at the 14-Y site and in the control.The relative abundances of N-fixing bacteria Mesorhizobium(32.94%),Sinorhizobium(0.24%),Frankia(0.71%),and Burkholderia(2.38%)at the 14-Y site were 1.33–3.97 times those in the control(24.19%,0.18%,0.32%and 0.60%,respectively),which was helpful for tailing N recovery.At the 14-Y site,Tylospora(50.24%),Luellia(11.02%),Tomentella(6.94%),and Chaetomium(4.34%)were the dominant fungal genera,while Tylospora(56.93%),Suillus(11.45%),and Penicillium(6.78%)predominated in the control.The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site(0.42%)was 4.2 times that in the control(0.1%),which may lead to the improved tailing P solubility.At the 14-Y site,woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas.This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings,thus providing a novel insight into ecological recovery and restoration after mining.展开更多
Sun Yanxin,Yao Jun,Xing Lijun,Zhang Youshan(Institute of Plant Nutrition & Resources,Beijing Academy of Agriculture and Forest Sciences,Beijing 100081).A Bacillus mucilaginosus RGBc13 was incubated together with e...Sun Yanxin,Yao Jun,Xing Lijun,Zhang Youshan(Institute of Plant Nutrition & Resources,Beijing Academy of Agriculture and Forest Sciences,Beijing 100081).A Bacillus mucilaginosus RGBc13 was incubated together with either a Pseudomonas sp.RGP11,a B.megaterinm RGPi or an Azotobacter chrococcus RGN21.It was found that RGBc13 had a strong ability to release K from glass powder and was not significantly affected by other bacteria although its growth was restrained.With the existence of RGN21,RGBc13 showed a stronger capacity to dissolve K from glass powder.RGBc13 promoted RGP11 growth,but restrained RGN21.RGPi growth was not affected by RGBc13.展开更多
文摘Plant biofertilization involves introducing compounds containing living mi-croorganisms into the coating medium to sustainably enhance plant production and soil health. This is a complex process that undergoes multiple stages of development before yielding a final product. The final biofertilizer is used by legumes-protein-rich crops in symbiosis with rhizobia to enable biological nitrogen fixation increasing natural soil fertility. This study aims to determine the optimal formulation of a rhizobial biofertilizer to improve the performance of soybean (Glycine max L. cv. Docko). To this end, soybean seeds obtained from IRAD were coated with different formulations derived from locally sourced materials. Palm kernel oil was used as an adhesive in one group, while corn powder served as an adhesive in another. The coated seeds were then sown in the field. The results indicate that the combination of pigeon pea powder + sugarcane molasses, with palm kernel oil as an adhesive, produced the best nodulation (nitrogen fixation). This formulation also led to significant improvements in growth (+350%) and total nitrogen content (+1100%) compared to the bacterial broth inoculum control (B0) (P ≤ 0.01). These findings represent a significant advancement in improving nitrogen-fixing bacterial inoculants and enhancing soil fertility for the sustainable cultivation of soybeans in this tropical soil.
基金supported by the National Natural Science Foundation of China(31930078,32301559)the Ministry of Science and Technology of China(2021YFD2200405,2021YFD2200402)+1 种基金Fundamental Research Funds of CAF(CAFYBB2021ZW001)the program for scientific research start-up funds of Guangdong Ocean University。
文摘Biodiversity experiments have shown that soil organic carbon(SOC)is not only a function of plant diversity,but is also closely related to the nitrogen(N)-fixing plants.However,the effect of N-fixing trees on SOC chemical stability is still little known,especially with the compounding effects of tree species diversity.An experimental field manipulation was established in subtropical plantations of southern China to explore the impacts of tree species richness(i.e.,one,two,four and six tree species)and with/without N-fixing trees on SOC chemical stability,as indicated by the ratio of easily oxidized organic carbon to SOC(EOC/SOC).Plant-derived C components in terms of hydrolysable plant lipids and lignin phenols were isolated from soils for evaluating their relative contributions to SOC chemical stability.The results showed that N-fixing tree species rather than tree species richness had a significant effect on EOC/SOC.Hydrolysable plant lipids and lignin phenols were negatively correlated with EOC/SOC,while hydrolysable plant lipids contributed more to EOC/SOC than lignin phenols,especially in the occurrence of N-fixing trees.The presence of N-fixing tree species led to an increase in soil N availability and a decrease in fungal abundance,promoting the selective retention of certain key components of hydrolysable plant lipids,thus enhancing SOC chemical stability.These findings underpin the crucial role of N-fixing trees in shaping SOC chemical stability,and therefore,preferential selection of N-fixing tree species in mixed plantations is an appropriate silvicultural strategy to improve SOC chemical stability in subtropical plantations.
基金supported by the National Natural Science Foundation of China (No. 30630015,30771704)
文摘We report on the effects of forest management practices of understory removal and N-fixing species（Cassia alata） addition on soil CO2 fluxes in an Eucalyptus urophylla plantation（EUp）,Acacia crassicarpa plantation（ACp）,10-species-mixed plantation（Tp）,and 30-species-mixed plantation（THp） using the static chamber method in southern China.Four forest management treatments,including（1） understory removal（UR）;（2） C.alata addition（CA）;（3） understory removal and replacement with C.alata（UR＋CA）;and（4） control without any disturbances（CK）,were applied in the above four forest plantations with three replications for each treatment.The results showed that soil CO2 fluxes rates remained at a high level during the rainy season（from April to September）,followed by a rapid decrease after October reaching a minimum in February.Soil CO2 fluxes were significantly higher（P 〈 0.01） in EUp（132.6 mg/（m2.hr）） and ACp（139.8 mg/（m2.hr）） than in Tp（94.0 mg/（m2.hr）） and THp（102.9 mg/（m2.hr））.Soil CO2 fluxes in UR and CA were significantly higher（P 〈 0.01） among the four treatments,with values of 105.7,120.4,133.6 and 112.2 mg/（m2.hr） for UR＋CA,UR,CA and CK,respectively.Soil CO2 fluxes were positively correlated with soil temperature（P 〈 0.01）,soil moisture（P 〈 0.01）,NO3？-N（P 〈 0.05）,and litterfall（P 〈 0.01）,indicating that all these factors might be important controlling variables for soil CO2 fluxes.This study sheds some light on our understanding of soil CO2 flux dynamics in forest plantations under various management practices.
基金supported by the National Natural Science Foundation of China(Nos.42293350,42293354,42293355,and 21707177).
文摘Rare earth element(REE)mining has wrought severe ecosystem destruction,particularly in the loss of carbon(C),nitrogen(N),and phosphorus(P).Furthermore,its effects on nutrient recovery characteristics and associated microbial abundance are still poorly understood.In this study,an investigation was conducted to determine C,N,and P recovery patterns and microbial communities in abandoned REE mining tailings with different abandoned durations of 1.5(1.5-Y),7(7-Y),10(10-Y),and 14(14-Y)years and at an unmined site(the control group)in Jiangxi Province,China.Longitudinal tailing delamination at each site was investigated in 0–15(layer 1)and 15–30(layer 2)cm tailing layers.During the abandoned duration of REE tailings,C and P in layer 1 continued to recover from 1.62 to 8.51 g kg^(-1) and from 0.71 to 1.94 g kg^(-1),respectively;N losses of 0.60 and 0.22 g kg^(-1) occurred at the 1.5-Y and 10-Y sites,while N in layer 1 slightly increased at the 14-Y site.Mesorhizobium,Methylosinus,Bradyrhizobium,Pseudomonas,and Azospirillum were dominant bacteria at the 14-Y site and in the control.The relative abundances of N-fixing bacteria Mesorhizobium(32.94%),Sinorhizobium(0.24%),Frankia(0.71%),and Burkholderia(2.38%)at the 14-Y site were 1.33–3.97 times those in the control(24.19%,0.18%,0.32%and 0.60%,respectively),which was helpful for tailing N recovery.At the 14-Y site,Tylospora(50.24%),Luellia(11.02%),Tomentella(6.94%),and Chaetomium(4.34%)were the dominant fungal genera,while Tylospora(56.93%),Suillus(11.45%),and Penicillium(6.78%)predominated in the control.The relative abundance of the P-dissolving fungus Aspergillus at the 14-Y site(0.42%)was 4.2 times that in the control(0.1%),which may lead to the improved tailing P solubility.At the 14-Y site,woody plants such as Pinus massoniana and native pioneering herbs and ferns such as Dicranopteris dichotoma and Nephrolepis auriculata probably invaded from adjacent areas.This study unraveled the natural restoration of plant and microbial communities along with soil nutrient changes in abandoned REE tailings,thus providing a novel insight into ecological recovery and restoration after mining.
文摘Sun Yanxin,Yao Jun,Xing Lijun,Zhang Youshan(Institute of Plant Nutrition & Resources,Beijing Academy of Agriculture and Forest Sciences,Beijing 100081).A Bacillus mucilaginosus RGBc13 was incubated together with either a Pseudomonas sp.RGP11,a B.megaterinm RGPi or an Azotobacter chrococcus RGN21.It was found that RGBc13 had a strong ability to release K from glass powder and was not significantly affected by other bacteria although its growth was restrained.With the existence of RGN21,RGBc13 showed a stronger capacity to dissolve K from glass powder.RGBc13 promoted RGP11 growth,but restrained RGN21.RGPi growth was not affected by RGBc13.
