Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of...Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.展开更多
The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stabil...The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stability was assessed by the most sensitive and informative biological indicators:microbiological(total number of bacteria),biochemical(catalase and dehydrogenase activity),and phytotoxic(changes in the length of wheat roots and shoots).Te contamination was simulated at concentrations of 0.5,1,3,10,and 30 possible permissible concentrations(PPC).It has been established that already at minimum concentrations of Te(0.5 and 1 PPC),the biological indicators of soils decrease.As a rule,a direct relationship between Te concentration and the degree of deterioration of the studied soil properties was observed.Te nitrate showed higher ecotoxicity than oxide.A stronger negative effect of Te contamination was manifested 10 and 30 days after contamination.After 90 days,the restoration of the biological properties of the soils was observed.Haplic Chernozem(Loamic)showed greater resistance to Te contamination than Haplic Cambisols Eutric and Eutric Arenosol.The obtained results can be used to predict environmental risks from soil contamination with Te and to develop maximum permissible concentrations of Te in soils of contrasting properties.展开更多
Phosphorus(P)deficiency is one of the main constraints on crop production in Arenosols(acid sandy soil).The high cost of P fertilizers may represent an insurmountable obstacle in many poor countries,leaving the exploi...Phosphorus(P)deficiency is one of the main constraints on crop production in Arenosols(acid sandy soil).The high cost of P fertilizers may represent an insurmountable obstacle in many poor countries,leaving the exploitation of their own calcareous and phosphate rocks as the only low-cost and long-term alternative.Biochar is suggested to have positive effects on soil properties;however,there is no published research on the synergistic effects of biochar and rocky materials in modifying soil properties.The aim of this study was to investigate the chemical and biochemical responses of an acid Arenosol treated with phosphate rock(PR),calcareous rock(CR),and biochar(BC),and the implications for corn yield.A soil from Marracuene District,Mozambique was used,where corn was grown for 90 d with the soil treated with:no addition(control),water-soluble zinc phosphite fertilizer(WSP),PR,WSP+CR,WSP+BC,WSP+CR+BC,PR+BC,and PR+CR+BC.Biochar was produced by pyrolysis of babycorn peels for 4 h at 450?C and applied at 11 g kg-1.The soil pHH2 Oincreased from about 4.54 in the control to 7.38 in the PR+CR+BC treatment.Easily oxidizable organic carbon,cation exchange capacity,and available P were higher in the treatments containing BC than in the control.The treatments containing CR and/or BC led to the highest activities of alkaline phosphomonoesterase,phosphodiesterase,andα-glucosidase,which increased P availability and gave the greatest biomass and yields.We suggest that biochar provides additional soluble P and supplies adsorption sites for phosphate,preventing its evolution to unavailable forms.Thus,PR applied together with BC contributed to an 840%yield increase compared to the control.The treatments containing WSP and BC facilitated phosphite oxidation to phosphate and increased crop yield.展开更多
基金supported by University of Latvia grant Nr. AAp2016/B041//Zd2016/AZ03 within the project “Climate change and sustainable use of natural resources”。
文摘Background: Natural afforestation of former agricultural lands with alder species is common in Europe. Symbiotic nitrogen fixation by actinomycetes associated with alder species has been widely used for improvement of soil properties of abandoned agricultural lands, but relatively little is known of the interactions of these processes with soil type and chemical composition. We conducted a space-for time study with soil sampling under and outside grey alder tree canopies on two different soil groups to explore effects of colonisation of former agricultural lands by alder on soil properties.Results: The results were analysed using analysis of variance. During the first 25 years after afforestation of former agricultural lands there was a significant increase in content of Ctot, Ntot, K+, Fe3+, Mn2+and available P in the topsoil(0–10 cm and 11–20 cm) of Dystric Arenosols soils, which are deficient in organic matter. Such trends were not evident in organic matter rich Endostagnic Umbrisols soils, in which exchangeable K+concentration decreased and exchangeable Fe3+and Al3+concentration increased.Conclusions: The results show that the effects of grey alder on soil chemical properties depend on initial soil properties. The invasion of agricultural land by grey alder leads to spatial variability of soil chemical properties creating a mosaic pattern.
基金support of the project of the Strategic Academic Leadership Program of the Southern Federal University(“Priority 2030”)(No.SP-12-24-04).
文摘The ecotoxicity of tellurium(Te)compounds(oxide and nitrate)is assessed by changing the biological properties of soils of contrasting properties:Haplic Chernozem(Loamic),Eutric Cambisol,and Eutric Arenosol.Soil stability was assessed by the most sensitive and informative biological indicators:microbiological(total number of bacteria),biochemical(catalase and dehydrogenase activity),and phytotoxic(changes in the length of wheat roots and shoots).Te contamination was simulated at concentrations of 0.5,1,3,10,and 30 possible permissible concentrations(PPC).It has been established that already at minimum concentrations of Te(0.5 and 1 PPC),the biological indicators of soils decrease.As a rule,a direct relationship between Te concentration and the degree of deterioration of the studied soil properties was observed.Te nitrate showed higher ecotoxicity than oxide.A stronger negative effect of Te contamination was manifested 10 and 30 days after contamination.After 90 days,the restoration of the biological properties of the soils was observed.Haplic Chernozem(Loamic)showed greater resistance to Te contamination than Haplic Cambisols Eutric and Eutric Arenosol.The obtained results can be used to predict environmental risks from soil contamination with Te and to develop maximum permissible concentrations of Te in soils of contrasting properties.
基金the Applied Research and Multi-sectorial Program(FIAM)(project contract No.5.2.1)granted by the Italian Cooperation and Development Agency(ICDA)to the Universidade Eduardo Mondlane
文摘Phosphorus(P)deficiency is one of the main constraints on crop production in Arenosols(acid sandy soil).The high cost of P fertilizers may represent an insurmountable obstacle in many poor countries,leaving the exploitation of their own calcareous and phosphate rocks as the only low-cost and long-term alternative.Biochar is suggested to have positive effects on soil properties;however,there is no published research on the synergistic effects of biochar and rocky materials in modifying soil properties.The aim of this study was to investigate the chemical and biochemical responses of an acid Arenosol treated with phosphate rock(PR),calcareous rock(CR),and biochar(BC),and the implications for corn yield.A soil from Marracuene District,Mozambique was used,where corn was grown for 90 d with the soil treated with:no addition(control),water-soluble zinc phosphite fertilizer(WSP),PR,WSP+CR,WSP+BC,WSP+CR+BC,PR+BC,and PR+CR+BC.Biochar was produced by pyrolysis of babycorn peels for 4 h at 450?C and applied at 11 g kg-1.The soil pHH2 Oincreased from about 4.54 in the control to 7.38 in the PR+CR+BC treatment.Easily oxidizable organic carbon,cation exchange capacity,and available P were higher in the treatments containing BC than in the control.The treatments containing CR and/or BC led to the highest activities of alkaline phosphomonoesterase,phosphodiesterase,andα-glucosidase,which increased P availability and gave the greatest biomass and yields.We suggest that biochar provides additional soluble P and supplies adsorption sites for phosphate,preventing its evolution to unavailable forms.Thus,PR applied together with BC contributed to an 840%yield increase compared to the control.The treatments containing WSP and BC facilitated phosphite oxidation to phosphate and increased crop yield.
