The long-term productivity of a soil is greatly influenced by cation exchange capacity（CEC）.Moreover,interactions between dominant base cations and other nutrients are important for the health and stability of grass...The long-term productivity of a soil is greatly influenced by cation exchange capacity（CEC）.Moreover,interactions between dominant base cations and other nutrients are important for the health and stability of grassland ecosystems.Soil exchangeable base cations and cation ratios were examined in a 11-year experiment with sheep manure application rates 0–1,500 g/（m2？a） in a semi-arid steppe in Inner Mongolia of China,aiming to clarify the relationships of base cations with soil p H,buffer capacity and fertility.Results showed that CEC and contents of exchangeable calcium（Ca2＋）,magnesium（Mg2＋）,potassium（K＋） and sodium（Na＋） were significantly increased,and Ca2＋ saturation tended to decrease,while K＋ saturation tended to increase with the increases of sheep manure application rates.The Ca2＋/Mg2＋ and Ca2＋/K＋ ratios decreased,while Mg2＋,K＋ and Na＋ saturations increased with increasing manure application rates.Both base cations and CEC were significantly and positively correlated with soil organic carbon（SOC） and soil p H.The increases of SOC and soil p H would be the dominant factors that contribute to the increase of cations in soil.On a comparison with the initial soil p H before the experiment,we deduced that sheep manure application could partly buffer soil p H decrease potentially induced by atmospheric deposition of nitrogen and sulfur.Our results indicate that sheep manure application is beneficial to the maintenance of base cations and the buffering of soil acidification,and therefore can improve soil fertility in the semi-arid steppes of northeastern China.展开更多
Background No-tillage(NT)is a widely used field management to reduce soil erosion and degradation and is suggested to be beneficial for enhancing soil carbon(C)sequestration capacity.Nonetheless,the effects of NT on s...Background No-tillage(NT)is a widely used field management to reduce soil erosion and degradation and is suggested to be beneficial for enhancing soil carbon(C)sequestration capacity.Nonetheless,the effects of NT on soil total carbon(TC)content in aeolian sandy soils are not extensively explored,and the underlying mechanisms are not clear.In our field experiments,the influence of NT and conventional tillage(CT)on sandy soil was studied.Methods We estimated the changes in soil TC in response to NT practice in a Cyperus esculentus L.field located at semi-arid Horqin sandy land,China.To unravel the underlying mechanisms,plant traits,soil properties and soil microbial characteristics were measured in parallel.The variations in soil bacterial community structure were investigated by 16S rRNA amplicon sequencing.The functionality of soil bacterial community was predicted based on OTU tables by using PICRUSt2.Results NT increased soil TC content in this sandy agroecosystem within a short-term experimental period,compared to CT.The underlying mechanisms might rely on three aspects.First,NT increased soil TC content through increasing photosynthesis and plant biomass,and thus,the plant-derived dissolved organic C.Second,NT increased the C immobilized in soil microbial biomass by increasing microbial C demands and C use efficiency.Third,NT increased the dominance of oligotrophic members in bacterial communities by decreasing available nutrient levels,which is associated with the recalcitrance and stability of the soil organic carbon.Conclusions The present study enriched our knowledge on the changes in the plant-soil-microbe continuum in response to NT in a semi-arid sandy agroecosystem.Still,this study provides a reference for modifying tillage practices to benefit crop yield as well as soil C sequestration.展开更多
Background:Soil microbial communities cope with an imbalanced supply of resources by adjusting their element acquisition and utilization strategies.Although soil pH has long been considered an essential driver of micr...Background:Soil microbial communities cope with an imbalanced supply of resources by adjusting their element acquisition and utilization strategies.Although soil pH has long been considered an essential driver of microbial growth and community composition,little is known about how soil acidification affects microbial acquisition and utilization of carbon(C)and nitrogen(N).To close the knowledge gap,we simulated soil acidification and created a pH gradient by adding eight levels of elemental sulfur(S)to the soil in a meadow steppe.Results:We found that S-induced soil acidification strongly enhanced the ratio of fungi to bacteria(F:B)and microbial biomass C to N(MBC:MBN)and subsequently decreased the C:N imbalance between microbial biomass and their resources.The linear decrease in the C:N imbalance with decreasing soil pH implied a conversion from N limitation to C limitation.To cope with enhanced C versus N limitation,soil microbial communities regulated the relative production of enzymes by increasing the ratio ofβ-glucosidase(BG,C-acquiring enzyme)to leucine aminopeptidase(LAP,N-acquiring enzyme),even though both enzymatic activities decreased with S addition.Structural equation modeling(SEM)suggested that higher C limitation and C:N-acquiring enzyme stimulated microbial carbon-use efficiency(CUE),which counteracted the negative effect of metal stress(i.e.,aluminum and manganese)under soil acidification.Conclusions:Overall,these results highlight the importance of stoichiometric controls in microbial adaption to soil acidification,which may help predict soil microbial responses to future acid deposition.展开更多
基金funded by the National Natural Science Foundation of China (41371251,31370009)the National Basic Research Program of China (2011CB403204)
文摘The long-term productivity of a soil is greatly influenced by cation exchange capacity（CEC）.Moreover,interactions between dominant base cations and other nutrients are important for the health and stability of grassland ecosystems.Soil exchangeable base cations and cation ratios were examined in a 11-year experiment with sheep manure application rates 0–1,500 g/（m2？a） in a semi-arid steppe in Inner Mongolia of China,aiming to clarify the relationships of base cations with soil p H,buffer capacity and fertility.Results showed that CEC and contents of exchangeable calcium（Ca2＋）,magnesium（Mg2＋）,potassium（K＋） and sodium（Na＋） were significantly increased,and Ca2＋ saturation tended to decrease,while K＋ saturation tended to increase with the increases of sheep manure application rates.The Ca2＋/Mg2＋ and Ca2＋/K＋ ratios decreased,while Mg2＋,K＋ and Na＋ saturations increased with increasing manure application rates.Both base cations and CEC were significantly and positively correlated with soil organic carbon（SOC） and soil p H.The increases of SOC and soil p H would be the dominant factors that contribute to the increase of cations in soil.On a comparison with the initial soil p H before the experiment,we deduced that sheep manure application could partly buffer soil p H decrease potentially induced by atmospheric deposition of nitrogen and sulfur.Our results indicate that sheep manure application is beneficial to the maintenance of base cations and the buffering of soil acidification,and therefore can improve soil fertility in the semi-arid steppes of northeastern China.
基金financially supported by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA 28060300)the National Key Research and Development Program of China(2019YFC0507601-03)the Applied Basic Research Programs of Liaoning Province(2023JH2/101700353)
文摘Background No-tillage(NT)is a widely used field management to reduce soil erosion and degradation and is suggested to be beneficial for enhancing soil carbon(C)sequestration capacity.Nonetheless,the effects of NT on soil total carbon(TC)content in aeolian sandy soils are not extensively explored,and the underlying mechanisms are not clear.In our field experiments,the influence of NT and conventional tillage(CT)on sandy soil was studied.Methods We estimated the changes in soil TC in response to NT practice in a Cyperus esculentus L.field located at semi-arid Horqin sandy land,China.To unravel the underlying mechanisms,plant traits,soil properties and soil microbial characteristics were measured in parallel.The variations in soil bacterial community structure were investigated by 16S rRNA amplicon sequencing.The functionality of soil bacterial community was predicted based on OTU tables by using PICRUSt2.Results NT increased soil TC content in this sandy agroecosystem within a short-term experimental period,compared to CT.The underlying mechanisms might rely on three aspects.First,NT increased soil TC content through increasing photosynthesis and plant biomass,and thus,the plant-derived dissolved organic C.Second,NT increased the C immobilized in soil microbial biomass by increasing microbial C demands and C use efficiency.Third,NT increased the dominance of oligotrophic members in bacterial communities by decreasing available nutrient levels,which is associated with the recalcitrance and stability of the soil organic carbon.Conclusions The present study enriched our knowledge on the changes in the plant-soil-microbe continuum in response to NT in a semi-arid sandy agroecosystem.Still,this study provides a reference for modifying tillage practices to benefit crop yield as well as soil C sequestration.
基金supported by the National Natural Science Foundation of China(31870441,32071563,and 31800398)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23080400)the Key State Research&Development Program of China(2016YFC0500601).
文摘Background:Soil microbial communities cope with an imbalanced supply of resources by adjusting their element acquisition and utilization strategies.Although soil pH has long been considered an essential driver of microbial growth and community composition,little is known about how soil acidification affects microbial acquisition and utilization of carbon(C)and nitrogen(N).To close the knowledge gap,we simulated soil acidification and created a pH gradient by adding eight levels of elemental sulfur(S)to the soil in a meadow steppe.Results:We found that S-induced soil acidification strongly enhanced the ratio of fungi to bacteria(F:B)and microbial biomass C to N(MBC:MBN)and subsequently decreased the C:N imbalance between microbial biomass and their resources.The linear decrease in the C:N imbalance with decreasing soil pH implied a conversion from N limitation to C limitation.To cope with enhanced C versus N limitation,soil microbial communities regulated the relative production of enzymes by increasing the ratio ofβ-glucosidase(BG,C-acquiring enzyme)to leucine aminopeptidase(LAP,N-acquiring enzyme),even though both enzymatic activities decreased with S addition.Structural equation modeling(SEM)suggested that higher C limitation and C:N-acquiring enzyme stimulated microbial carbon-use efficiency(CUE),which counteracted the negative effect of metal stress(i.e.,aluminum and manganese)under soil acidification.Conclusions:Overall,these results highlight the importance of stoichiometric controls in microbial adaption to soil acidification,which may help predict soil microbial responses to future acid deposition.
