This study presents bulk chemical compositions of the Tongmuling soil profile, which developed on dolostone, and the overlying strata covering the bedrock in the central Guizhou province(southern China). The chemical ...This study presents bulk chemical compositions of the Tongmuling soil profile, which developed on dolostone, and the overlying strata covering the bedrock in the central Guizhou province(southern China). The chemical weathering characteristics of the studied profile were investigated and the inheritance relationships between the terra rossa and overlying strata were discussed. The results show that there is no remarkable variation in the major elements and weathering indices from the rock–soil interface to the topsoil, indicating that the studied profile was not typical for in situ crustal chemical weathering. The terra rossa were mainly composed of Si O_2, Al_2O_3 and Fe_2O_3. Compared with the insoluble residues and overlying strata, the terra rossa are characterized by an enrichment of Y and Cs and depletion of Ba and Sr. The subsoil shows a notable Ce negative anomaly, characterized by heavy rare earth element enrichment(L/H = 1.55–3.74), whereas the topsoil shows a positive Ce anomaly with light rare earth element enrichment(L/H = 5.93–9.14). According to Laterite-forming capacity estimates, the terra rossa could not have only been formed from acid-insoluble residues from the bedrock; Al_2O_3 versus Fe_2O_3and Nb plotted against Ta show significant positive correlations between the terra rossa and overlying strata. The Eu/Eu* versusGd_N/Yb_Nand ternary diagrams for Sc, Th, Zr, and Ta suggest that the overlying strata could also provide parent materials for the genesis of terra rossa.展开更多
Geochemical,mineralogical,and micromorphological characteristics of soils and their relevant parent rocks including loess,ignimbrite,sandstone and limestone were investigated to identify the soil-parent material unifo...Geochemical,mineralogical,and micromorphological characteristics of soils and their relevant parent rocks including loess,ignimbrite,sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province,northern Iran.Highly developed Calcixerolls and moderately developed Haploxerepts were formed on loess and limestone,respectively.In contrast,the soils formed on ignimbrite and sandstone were nondeveloped Entisols.Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material.In loess derived soils however,smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation.In limestone,illite and vermiculite were dominant both in the A and C horizons.Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically.Chemical index of alteration(CIA),micromorphological index of soil development(MISECA),smectite/illite+chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development.Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively.Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.展开更多
Six tea plantations with different soil-forming parent materials, the same tea variety and tea age and similar landforms and management were selected to conduct a systematic study on the relationship between soil prop...Six tea plantations with different soil-forming parent materials, the same tea variety and tea age and similar landforms and management were selected to conduct a systematic study on the relationship between soil properties and tea quality. The results showed that the quality of tea grown on the soils derived from granites, arenaceous shales, argillaceous sandstones, was superior; those on the soils derived from limestones,dolomites, Quaternary red clays, were inferior. Further study showed that sandy soils were beneficial to improving amino acid content of tea, and clayey soils made it decrease; high content of bases might decrease the contents of tea polypenols, caffeine, water extracts, but promote the content of amino acids; available phosphorous was significantly positively correlated with water extracts, but significantly negatively correlated with carbine; slowly available potassium was positively correlated with amino acid content. Soil parent materials should be regarded as an important factor in evaluating the adaptability of tea to soils.展开更多
<span style="white-space:normal;">There has been increased interest in soil organic carbon in recent times because of its role in carbon sequestration. Different parent materials affect soil properties...<span style="white-space:normal;">There has been increased interest in soil organic carbon in recent times because of its role in carbon sequestration. Different parent materials affect soil properties and hence will influence how much carbon is sequestered by soil. The study was conducted in June 2019 to investigate soil carbon stock in forest soils with respect to their parent materials in three States in South-eastern Nigeria. Sampling was aided by the location map of the area and free soil survey method was used to locate sampling points. 0ne profile was dug in each location and described using the Food and Agricultural Organization guideline. A total of twelve soil samples were collected and analyzed for selected properties. Results showed that sand content was significantly higher in soils under coastal plain sands (851.96 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) and was lowest in soils of Imo clay shale (605.60 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;">−1</sup><span style="white-space:normal;">). Clay content was higher in soils of Imo clay shale (277.34 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) and was lowest in coastal plain sand (118.80 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">). Silt and clay had moderate variation in coastal plain sand (>15 ≤ 35%) and high variations in Asu River and Imo clay shale (CV > 35%). The soils studied were generally acidic with values ranging (3.52) in soils formed from coastal plain sand, followed by forest soils of Imo clay shale (3.64) and Asu river group (3.85). Soil organic carbon decreased with increase in soil depth in all soil parent materials studied. Mean values ranged from 6.14 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;"> in soil underlain by coastal plain sand to 10.62 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) in soils of Imo clay shale. Soil carbon sequestered under the three different parent materials ranged from 1575 - 4676.41 (g<span style="white-space:nowrap;">·</span>cm</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:normal;">). Also, soil depth had a notable impact on carbon sequestration with values ranging from 1529.42 - 4374.0541 (g<span style="white-space:nowrap;">·</span>cm</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:normal;">) and the thicker the horizon, the more carbon sequestered. Hence, the study concluded that more carbon is sequestered in the subsurface horizons of the soil pedons than in the epipedons.</span>展开更多
Soil chemical degradation caused by acidity is a serious constraint to food production in most parts of the Tropics. It was in the bid to proffer solution to this that the present study was conceived. Anincubation stu...Soil chemical degradation caused by acidity is a serious constraint to food production in most parts of the Tropics. It was in the bid to proffer solution to this that the present study was conceived. Anincubation study was conducted at the laboratory of Soil Science and Meteorology Department of Michael Okpara University of Agriculture Umudike. The aim was to ascertain the effect of amendments namely: Control (no amendment), Biochar, Ash, Lime, Biochar + Poultry Manure, Ash + Poultry Manure and Lime + Poultry Manure, on soil pH and exchangeable acidity of Sandstone, Shale and Alluvium. The rate of application was 1.43 g for the sole amendments and 0.72 g each for the combined amendments to give an equivalent of 2 t/ha. They were applied to 100 g of the soil and replicated three times in a Completely Randomized Design. The incubation study lasted for eighty-four days, the pH and exchangeable acidity were determined at fourteen days intervals. The result obtained revealed that all the treatments increased the soil pH and decreased the exchangeable acidity over the control. In all parent materials, applied Lime and Lime + Pm significantly (p < 0.05) gave the highest pH of 6.6, 6.9 and 7.2 for Shale, Sandstone and Alluvium respectively on the 28<sup>th</sup> day of incubation which, was the time, the maximum pH value was attained. Biochar and Biochar + Pm were considered the appropriate amendments because the pH values they gave were towards neutral, unlike that of Lime and Lime + Pm that were towards alkaline. It is recommended that field trial of this work is conducted.展开更多
基金financially supported by the National Basic Research Program of China(Grants No.2006CB403202)
文摘This study presents bulk chemical compositions of the Tongmuling soil profile, which developed on dolostone, and the overlying strata covering the bedrock in the central Guizhou province(southern China). The chemical weathering characteristics of the studied profile were investigated and the inheritance relationships between the terra rossa and overlying strata were discussed. The results show that there is no remarkable variation in the major elements and weathering indices from the rock–soil interface to the topsoil, indicating that the studied profile was not typical for in situ crustal chemical weathering. The terra rossa were mainly composed of Si O_2, Al_2O_3 and Fe_2O_3. Compared with the insoluble residues and overlying strata, the terra rossa are characterized by an enrichment of Y and Cs and depletion of Ba and Sr. The subsoil shows a notable Ce negative anomaly, characterized by heavy rare earth element enrichment(L/H = 1.55–3.74), whereas the topsoil shows a positive Ce anomaly with light rare earth element enrichment(L/H = 5.93–9.14). According to Laterite-forming capacity estimates, the terra rossa could not have only been formed from acid-insoluble residues from the bedrock; Al_2O_3 versus Fe_2O_3and Nb plotted against Ta show significant positive correlations between the terra rossa and overlying strata. The Eu/Eu* versusGd_N/Yb_Nand ternary diagrams for Sc, Th, Zr, and Ta suggest that the overlying strata could also provide parent materials for the genesis of terra rossa.
基金Gorgan University of Agricultural Sciences and Natural Resources for the support of this study
文摘Geochemical,mineralogical,and micromorphological characteristics of soils and their relevant parent rocks including loess,ignimbrite,sandstone and limestone were investigated to identify the soil-parent material uniformity and the weathering degree of soils in Golestan Province,northern Iran.Highly developed Calcixerolls and moderately developed Haploxerepts were formed on loess and limestone,respectively.In contrast,the soils formed on ignimbrite and sandstone were nondeveloped Entisols.Illite was the dominant clay mineral found in ignimbrite and sandstone in both the A horizon and parent material.In loess derived soils however,smectite was dominant especially in the Bt horizon compared to its parent material indicating partly to its pedogenic formation.In limestone,illite and vermiculite were dominant both in the A and C horizons.Ti/Zr ratio proved that the studied soils were closely related to their underlying parent materials geochemically.Chemical index of alteration(CIA),micromorphological index of soil development(MISECA),smectite/illite+chlorite ratio and magnetic susceptibility were applied to investigate the degree of soil development.Results showed that the most and the least developed soils were those formed on loess deposits and limestone,respectively.Application of the different geochemical and pedogenetic approaches was proved to be useful in identifying the relevance of soils to their underlying parent materials and also their degree of development.
文摘Six tea plantations with different soil-forming parent materials, the same tea variety and tea age and similar landforms and management were selected to conduct a systematic study on the relationship between soil properties and tea quality. The results showed that the quality of tea grown on the soils derived from granites, arenaceous shales, argillaceous sandstones, was superior; those on the soils derived from limestones,dolomites, Quaternary red clays, were inferior. Further study showed that sandy soils were beneficial to improving amino acid content of tea, and clayey soils made it decrease; high content of bases might decrease the contents of tea polypenols, caffeine, water extracts, but promote the content of amino acids; available phosphorous was significantly positively correlated with water extracts, but significantly negatively correlated with carbine; slowly available potassium was positively correlated with amino acid content. Soil parent materials should be regarded as an important factor in evaluating the adaptability of tea to soils.
文摘<span style="white-space:normal;">There has been increased interest in soil organic carbon in recent times because of its role in carbon sequestration. Different parent materials affect soil properties and hence will influence how much carbon is sequestered by soil. The study was conducted in June 2019 to investigate soil carbon stock in forest soils with respect to their parent materials in three States in South-eastern Nigeria. Sampling was aided by the location map of the area and free soil survey method was used to locate sampling points. 0ne profile was dug in each location and described using the Food and Agricultural Organization guideline. A total of twelve soil samples were collected and analyzed for selected properties. Results showed that sand content was significantly higher in soils under coastal plain sands (851.96 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) and was lowest in soils of Imo clay shale (605.60 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;">−1</sup><span style="white-space:normal;">). Clay content was higher in soils of Imo clay shale (277.34 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) and was lowest in coastal plain sand (118.80 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">). Silt and clay had moderate variation in coastal plain sand (>15 ≤ 35%) and high variations in Asu River and Imo clay shale (CV > 35%). The soils studied were generally acidic with values ranging (3.52) in soils formed from coastal plain sand, followed by forest soils of Imo clay shale (3.64) and Asu river group (3.85). Soil organic carbon decreased with increase in soil depth in all soil parent materials studied. Mean values ranged from 6.14 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;"> in soil underlain by coastal plain sand to 10.62 g<span style="white-space:nowrap;">·</span>kg</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>1</sup><span style="white-space:normal;">) in soils of Imo clay shale. Soil carbon sequestered under the three different parent materials ranged from 1575 - 4676.41 (g<span style="white-space:nowrap;">·</span>cm</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:normal;">). Also, soil depth had a notable impact on carbon sequestration with values ranging from 1529.42 - 4374.0541 (g<span style="white-space:nowrap;">·</span>cm</span><sup style="white-space:normal;"><span style="white-space:nowrap;">−</span>2</sup><span style="white-space:normal;">) and the thicker the horizon, the more carbon sequestered. Hence, the study concluded that more carbon is sequestered in the subsurface horizons of the soil pedons than in the epipedons.</span>
文摘Soil chemical degradation caused by acidity is a serious constraint to food production in most parts of the Tropics. It was in the bid to proffer solution to this that the present study was conceived. Anincubation study was conducted at the laboratory of Soil Science and Meteorology Department of Michael Okpara University of Agriculture Umudike. The aim was to ascertain the effect of amendments namely: Control (no amendment), Biochar, Ash, Lime, Biochar + Poultry Manure, Ash + Poultry Manure and Lime + Poultry Manure, on soil pH and exchangeable acidity of Sandstone, Shale and Alluvium. The rate of application was 1.43 g for the sole amendments and 0.72 g each for the combined amendments to give an equivalent of 2 t/ha. They were applied to 100 g of the soil and replicated three times in a Completely Randomized Design. The incubation study lasted for eighty-four days, the pH and exchangeable acidity were determined at fourteen days intervals. The result obtained revealed that all the treatments increased the soil pH and decreased the exchangeable acidity over the control. In all parent materials, applied Lime and Lime + Pm significantly (p < 0.05) gave the highest pH of 6.6, 6.9 and 7.2 for Shale, Sandstone and Alluvium respectively on the 28<sup>th</sup> day of incubation which, was the time, the maximum pH value was attained. Biochar and Biochar + Pm were considered the appropriate amendments because the pH values they gave were towards neutral, unlike that of Lime and Lime + Pm that were towards alkaline. It is recommended that field trial of this work is conducted.
