Rice cropping method is primarily decided by soil moisture regime.System of rice intensification(SRI)and direct-seeded aerobic rice are two primary modifications of traditional wetland rice.Understanding rice rhizosph...Rice cropping method is primarily decided by soil moisture regime.System of rice intensification(SRI)and direct-seeded aerobic rice are two primary modifications of traditional wetland rice.Understanding rice rhizosphere microbiome and functioning as influenced by these cropping methods is essential for sustaining rice productivity.The objective of this study was to assess the impact of three different rice cropping methods(wetland rice,SRI,and aerobic rice)on the biochemical properties and bacterial communities within the rice rhizosphere across three key rice growth stages:tillering,flowering,and maturity.Soil organic carbon(SOC),microbial biomass carbon(MBC),dehydrogenase activity,substrate-induced respiration(SIR),and metabolic quotient(MQ)were assessed along with high-throughput 16S rRNA sequencing of rice rhizosphere soils.The rice rhizosphere soil registered the highest SOC,MBC,and dehydrogenase activity in SRI followed by wetland rice and then aerobic rice.Cropping method had a minimal impact on SIR and MQ.Along with cropping method,growth stage also significantly altered these biological attributes of rice rhizosphere.The trends of the highest SOC content and dehydrogenase activity at the flowering stage and the highest MBC content and SIR at the tillering stage of rice were observed in all three rice cropping methods.The analysis of bacterial communities,based on 16S rRNA gene sequencing,revealed that both cropping method and growth stage significantly impacted the composition of rhizosphere microbiomes.However,the influence of cropping method was less pronounced compared to growth stage.Cropping method caused notable shifts in the abundances of Proteobacteria,Bacteroidetes,and Chloroflexi,while growth stage affected the abundances of Proteobacteria,Actinobacteria,Cyanobacteria,Firmicutes,Chloroflexi,and Bacteroidetes.Based on these results,the SRI method led to higher diversification to the rhizosphere bacteriobiota,as well as greater incorporation of carbon into the soil and increased dehydrogenase activity compared to wetland rice and aerobic rice.This study deepens our understanding of how different cropping methods influence plant-microbe interaction and the implications for overall rice productivity and soil health.展开更多
Soil depth generally varies in mountainous regions in rather complex ways.Conventional soil survey methods for evaluating the soil depth in mountainous and hilly regions require a lot of time,effort and consequently r...Soil depth generally varies in mountainous regions in rather complex ways.Conventional soil survey methods for evaluating the soil depth in mountainous and hilly regions require a lot of time,effort and consequently relatively large budget to perform.This study was conducted to explore the relationships between soil depth and topographic attributes in a hilly region in western Iran.For this,one hundred sampling points were selected using randomly stratified methodology,and considering all geomorphic surfaces including summit,shoulder,backslope,footslope and toeslope;and soil depth was actually measured.Eleven primary and secondary topographic attributes were derived from the digital elevation model(DEM) at the study area.The result of multiple linear regression indicated that slope,wetness index,catchment area and sediment transport index,which were included in the model,could explain about 76 % of total variability in soil depth at the selected site.This proposed approach may be applicable to other hilly regions in the semi-arid areas at a larger scale.展开更多
Introduction:The information available on the sensitivity of soil biotic and abiotic attributes,which can be used to track the impact of reforestation in riparian buffers,is often insufficient to refine management pra...Introduction:The information available on the sensitivity of soil biotic and abiotic attributes,which can be used to track the impact of reforestation in riparian buffers,is often insufficient to refine management practices and convince stakeholders of the benefits of reforestation.Methods:In this study,conducted in Victoria,Australia,the changes in soil biotic and abiotic attributes,organic carbon(OC),mineral nitrogen(MN),total dissolved solutes(TDS)and pH were characterised to assess the impact of land-use change from bare riparian(BR)to reforested riparian(RR).Additionally,the benefits of revegetating a deforested creek bank with regard to salinity abatement and C-sequestration potentials were assessed.Results:The TDS depletion in the RR strips varied spatiotemporally from 65 to 169 mg/L,the net OC deposition from 16 to 19 g C/kg soil and MN deposition from 1.2 to 2.1 g N/kg soil,respectively.Additionally,the net changes in pH from alkaline to near neutral condition varied by 0.4 to 1.0 pH units.Approximately 30%to 60%of the net OC depletion after deforestation was redeposited under RR over 3 to 6 years.The TDS depletion after land-use changed from BR to RR ranged from 15 to 32%over 3 to 6 years.Conclusion:The soil attributes OC,MN and TDS characteristics under different land-use practices varied spatiotemporally.This information may be useful to convince stakeholders to undertake reforestation of creek banks for salinity abatement,and that change in land-use has the potential to increase C sequestration at a farm scale.展开更多
The destruction of natural ecosystems is an important issue in many parts of the world. In the west of Iran, a vast area of the Zagros Mountain range is covered by typical vegetation including several rare plant speci...The destruction of natural ecosystems is an important issue in many parts of the world. In the west of Iran, a vast area of the Zagros Mountain range is covered by typical vegetation including several rare plant species, of which many are currently considered endangered by anthropogenic activities. Despite the important role of soil seed banks to help conserve these degraded plant communities, the floristic studies in the Zagros forests have only focused on aboveground vegetation. In this study, the characteristics of soil seed banks and above-ground vegetation were examined at two forest sites: an undisturbed control(Un) and a disturbed(D) site. The objectives of this study were 1) to investigate the diversity of above-ground vegetation and soil seed banks in disturbed and undisturbed forests, 2) to examine the soil properties and the germination characteristics of the soil seed bank in disturbed and undisturbed oak forests and 3) to estimate the potential of soil seed banks in the restoration of disturbed sites. The results show that soil properties between Un and D sites were significantly different with higher values of pH, NH 4-N, N tot, CEC, OC, clay and canopy percentage in the Un site than in the D site. The Simpson diversity, Margalef richness and evenness indices differed significantly between sites, either for the soil seed banks or the above-ground vegetation. After a period of 26 weeks, the germination speed and the mean daily number of germinants were significantly different between Un and D sites. Without other conservation measures, soil seed banks alone cannot result in a full recovery after severe disturbances in the oak forests of Zagros.展开更多
Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. T...Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. The goal of this research is to determine some plant and soil indicators of hilly winter rangelands of Eastern and Southern slopes of Chaharbagh region in Golestan province. By considering plant cover and soil surface attributes, it used the SSCC （soil surface classification） method to assess soil surface attributes. The length and width of ecological patches were measured in the forms of lichen, lichen-Grass, forbs, shrub and bare soil inter patches with litter. Also in this research, it measured the 11 soil surface parameters. These parameters are belonging to three main soil attributes stability, infiltration and nutrient cycles. These three indicators were measured in east and west of Eastern and Southern slopes of this ecosystem and showed significance differences （p 〈 0.05） in shrub, forbs and lichen-grass. In southern and especially in west aspect, these indicators in shrub were more than Eastern. But, in lossy hill of Eastern, lichen-grass patch is more significant. The most important ecological indicators of east landscapes of this region are forbs and lichen-grass.展开更多
Introduction:An accurate and reliable detection of soil physicochemical attributes(SPAs)is a difficult and complicated issue in soil science.The SPA may be varied spatially and temporally with the complexity of nature...Introduction:An accurate and reliable detection of soil physicochemical attributes(SPAs)is a difficult and complicated issue in soil science.The SPA may be varied spatially and temporally with the complexity of nature.In the past,SPA detection has been obtained through routine soil chemical and physical laboratory analysis.However,these laboratory methods do not fulfill the rapid requirements.Accordingly,diffuse reflectance spectroscopy(DRS)can be used to nondestructively detect and characterize soil attributes with superior solution.In the present article,we report a study done through spectral curves in the visible(350–700 nm)and near-infrared(700–2500 nm)(VNIR)region of 74 soil specimens which were agglomerated by farming sectors of Phulambri Tehsil of the Aurangabad region of Maharashtra,India.The quantitative analysis of VNIR spectrum was done.Results:The spectra of agglomerated farming soils were acquired by the Analytical Spectral Device(ASD)Field spec 4 spectroradiometer.The soil spectra of the VNIR region were preprocessed to get pure spectra which were the input for regression modeling.The partial least squares regression(PLSR)model was computed to construct the calibration models,which were individually validated for the prediction of SPA from the soil spectrum.The computed model was based on a correlation study between reflected spectra and detected SPA.The detected SPAs were soil organic carbon(SOC),nitrogen(N),soil organic matter(SOM),pH values,electrical conductivity(EC),phosphorus(P),potassium(K),iron(Fe),sand,silt,and clay.The accuracy of the PLSR model-validated determinant(R^(2))values were SOC 0.89,N 0.68,SOM 0.93,pH values 0.82,EC 0.89,P 0.98,K 0.82,Fe 0.94,sand 0.98,silt 0.90,and clay 0.69 with root mean square error of prediction(RMSEP)3.51,4.34,2.66,2.12,4.11,1.41,4.22,1.56,1.89,1.97,and 9.91,respectively.According to the experimental results,the VNIR-DRS was better for detection of SPA and produced more accurate predictions for SPA.Conclusions:In conclusion,the methods examined here offered rapid and novel detection of SPA from reflectance spectroscopy.The outcome of the present research will be apt for precision farming and decision-making.展开更多
基金support from the Indian Council of Agricultural Research through the All India Network Project(AINP)on Soil Biodiversity and Biofertilizers to conduct this study is acknowledged。
文摘Rice cropping method is primarily decided by soil moisture regime.System of rice intensification(SRI)and direct-seeded aerobic rice are two primary modifications of traditional wetland rice.Understanding rice rhizosphere microbiome and functioning as influenced by these cropping methods is essential for sustaining rice productivity.The objective of this study was to assess the impact of three different rice cropping methods(wetland rice,SRI,and aerobic rice)on the biochemical properties and bacterial communities within the rice rhizosphere across three key rice growth stages:tillering,flowering,and maturity.Soil organic carbon(SOC),microbial biomass carbon(MBC),dehydrogenase activity,substrate-induced respiration(SIR),and metabolic quotient(MQ)were assessed along with high-throughput 16S rRNA sequencing of rice rhizosphere soils.The rice rhizosphere soil registered the highest SOC,MBC,and dehydrogenase activity in SRI followed by wetland rice and then aerobic rice.Cropping method had a minimal impact on SIR and MQ.Along with cropping method,growth stage also significantly altered these biological attributes of rice rhizosphere.The trends of the highest SOC content and dehydrogenase activity at the flowering stage and the highest MBC content and SIR at the tillering stage of rice were observed in all three rice cropping methods.The analysis of bacterial communities,based on 16S rRNA gene sequencing,revealed that both cropping method and growth stage significantly impacted the composition of rhizosphere microbiomes.However,the influence of cropping method was less pronounced compared to growth stage.Cropping method caused notable shifts in the abundances of Proteobacteria,Bacteroidetes,and Chloroflexi,while growth stage affected the abundances of Proteobacteria,Actinobacteria,Cyanobacteria,Firmicutes,Chloroflexi,and Bacteroidetes.Based on these results,the SRI method led to higher diversification to the rhizosphere bacteriobiota,as well as greater incorporation of carbon into the soil and increased dehydrogenase activity compared to wetland rice and aerobic rice.This study deepens our understanding of how different cropping methods influence plant-microbe interaction and the implications for overall rice productivity and soil health.
文摘Soil depth generally varies in mountainous regions in rather complex ways.Conventional soil survey methods for evaluating the soil depth in mountainous and hilly regions require a lot of time,effort and consequently relatively large budget to perform.This study was conducted to explore the relationships between soil depth and topographic attributes in a hilly region in western Iran.For this,one hundred sampling points were selected using randomly stratified methodology,and considering all geomorphic surfaces including summit,shoulder,backslope,footslope and toeslope;and soil depth was actually measured.Eleven primary and secondary topographic attributes were derived from the digital elevation model(DEM) at the study area.The result of multiple linear regression indicated that slope,wetness index,catchment area and sediment transport index,which were included in the model,could explain about 76 % of total variability in soil depth at the selected site.This proposed approach may be applicable to other hilly regions in the semi-arid areas at a larger scale.
基金Financial support for this project was provided by the Corangamite Catchment Management Authority(Funding number CO0910.06.051).
文摘Introduction:The information available on the sensitivity of soil biotic and abiotic attributes,which can be used to track the impact of reforestation in riparian buffers,is often insufficient to refine management practices and convince stakeholders of the benefits of reforestation.Methods:In this study,conducted in Victoria,Australia,the changes in soil biotic and abiotic attributes,organic carbon(OC),mineral nitrogen(MN),total dissolved solutes(TDS)and pH were characterised to assess the impact of land-use change from bare riparian(BR)to reforested riparian(RR).Additionally,the benefits of revegetating a deforested creek bank with regard to salinity abatement and C-sequestration potentials were assessed.Results:The TDS depletion in the RR strips varied spatiotemporally from 65 to 169 mg/L,the net OC deposition from 16 to 19 g C/kg soil and MN deposition from 1.2 to 2.1 g N/kg soil,respectively.Additionally,the net changes in pH from alkaline to near neutral condition varied by 0.4 to 1.0 pH units.Approximately 30%to 60%of the net OC depletion after deforestation was redeposited under RR over 3 to 6 years.The TDS depletion after land-use changed from BR to RR ranged from 15 to 32%over 3 to 6 years.Conclusion:The soil attributes OC,MN and TDS characteristics under different land-use practices varied spatiotemporally.This information may be useful to convince stakeholders to undertake reforestation of creek banks for salinity abatement,and that change in land-use has the potential to increase C sequestration at a farm scale.
文摘The destruction of natural ecosystems is an important issue in many parts of the world. In the west of Iran, a vast area of the Zagros Mountain range is covered by typical vegetation including several rare plant species, of which many are currently considered endangered by anthropogenic activities. Despite the important role of soil seed banks to help conserve these degraded plant communities, the floristic studies in the Zagros forests have only focused on aboveground vegetation. In this study, the characteristics of soil seed banks and above-ground vegetation were examined at two forest sites: an undisturbed control(Un) and a disturbed(D) site. The objectives of this study were 1) to investigate the diversity of above-ground vegetation and soil seed banks in disturbed and undisturbed forests, 2) to examine the soil properties and the germination characteristics of the soil seed bank in disturbed and undisturbed oak forests and 3) to estimate the potential of soil seed banks in the restoration of disturbed sites. The results show that soil properties between Un and D sites were significantly different with higher values of pH, NH 4-N, N tot, CEC, OC, clay and canopy percentage in the Un site than in the D site. The Simpson diversity, Margalef richness and evenness indices differed significantly between sites, either for the soil seed banks or the above-ground vegetation. After a period of 26 weeks, the germination speed and the mean daily number of germinants were significantly different between Un and D sites. Without other conservation measures, soil seed banks alone cannot result in a full recovery after severe disturbances in the oak forests of Zagros.
文摘Getting aware of one kind of soil surface attributs is very important. Assessment of important attributes of soil and vegetation can help us to be aware of rangeland potential and help us to determine its situation. The goal of this research is to determine some plant and soil indicators of hilly winter rangelands of Eastern and Southern slopes of Chaharbagh region in Golestan province. By considering plant cover and soil surface attributes, it used the SSCC （soil surface classification） method to assess soil surface attributes. The length and width of ecological patches were measured in the forms of lichen, lichen-Grass, forbs, shrub and bare soil inter patches with litter. Also in this research, it measured the 11 soil surface parameters. These parameters are belonging to three main soil attributes stability, infiltration and nutrient cycles. These three indicators were measured in east and west of Eastern and Southern slopes of this ecosystem and showed significance differences （p 〈 0.05） in shrub, forbs and lichen-grass. In southern and especially in west aspect, these indicators in shrub were more than Eastern. But, in lossy hill of Eastern, lichen-grass patch is more significant. The most important ecological indicators of east landscapes of this region are forbs and lichen-grass.
文摘Introduction:An accurate and reliable detection of soil physicochemical attributes(SPAs)is a difficult and complicated issue in soil science.The SPA may be varied spatially and temporally with the complexity of nature.In the past,SPA detection has been obtained through routine soil chemical and physical laboratory analysis.However,these laboratory methods do not fulfill the rapid requirements.Accordingly,diffuse reflectance spectroscopy(DRS)can be used to nondestructively detect and characterize soil attributes with superior solution.In the present article,we report a study done through spectral curves in the visible(350–700 nm)and near-infrared(700–2500 nm)(VNIR)region of 74 soil specimens which were agglomerated by farming sectors of Phulambri Tehsil of the Aurangabad region of Maharashtra,India.The quantitative analysis of VNIR spectrum was done.Results:The spectra of agglomerated farming soils were acquired by the Analytical Spectral Device(ASD)Field spec 4 spectroradiometer.The soil spectra of the VNIR region were preprocessed to get pure spectra which were the input for regression modeling.The partial least squares regression(PLSR)model was computed to construct the calibration models,which were individually validated for the prediction of SPA from the soil spectrum.The computed model was based on a correlation study between reflected spectra and detected SPA.The detected SPAs were soil organic carbon(SOC),nitrogen(N),soil organic matter(SOM),pH values,electrical conductivity(EC),phosphorus(P),potassium(K),iron(Fe),sand,silt,and clay.The accuracy of the PLSR model-validated determinant(R^(2))values were SOC 0.89,N 0.68,SOM 0.93,pH values 0.82,EC 0.89,P 0.98,K 0.82,Fe 0.94,sand 0.98,silt 0.90,and clay 0.69 with root mean square error of prediction(RMSEP)3.51,4.34,2.66,2.12,4.11,1.41,4.22,1.56,1.89,1.97,and 9.91,respectively.According to the experimental results,the VNIR-DRS was better for detection of SPA and produced more accurate predictions for SPA.Conclusions:In conclusion,the methods examined here offered rapid and novel detection of SPA from reflectance spectroscopy.The outcome of the present research will be apt for precision farming and decision-making.
