Study on chemical properties of some forest red soils of Hunan Province
0
Citation
0
Reference
20
Related Paper
Abstract:
Chemical properties of red soils in 6 places in the forestry of Hunan China were studied. The result indicates,the soils were of strong acidity with pH 4. 11 - 4. 96; differences in the organic content were obvious,ranging between 9. 50-37. 6 g/kg;the contents of total nitrogen were not high,0. 321 - 1. 70 g/kgfthe content of total phosphorus were 0. 126 - 0. 441 g/kg;the contents of total potassium were relatively high,up to 10. 5 - 18. 1 g/kgjthe content of exchangeability cation were widely different,ranging from 3. 86 - 50. 6 mmol/kg;Exchangeability cation CEC number value were up to 13. 9 - 34. 0 cmol/kg. The survey data of Cu,Zn,Pb and Cd indicate,the soils have not been polluted by heavy metals. In view of such conditions as the soil chemical property .vegetation and geographical position of the ground, etc. synthetically, corresponding development suggestions were put forward.Keywords:
Cation-exchange capacity
Soil survey
Cite
Yellow River Irrigation Region(YRIR) is one of China's important grain production bases.The contents and chemical forms of heavy metals in the agricultural soils of the region are related to sustainable agricultural development.The distribution of main soil properties [total organic carbon(TOC),total nitrogen(TN),total phosphorus(TP) and CaCO3] and heavy metals(Pb,Cd,Cu and Zn) in the agricultural soils of YRIR were investigated using 45 soil samples.Five soil profiles(in the 0~100 cm soil layer) and arable soils(in the 0~15 cm and 15~30 cm soil layers) were collected from agricultural lands under rice-wheat rotation system in the northern suburb of Kaifeng.The region belongs to the Heigangkou YRIR,which is sufficiently representative of the YRIR.The chemical forms of heavy metals were analyzed by sequential extraction and the concentrations determined with ICP-AES and ICP-MS.Results showed that under long-term irrigation and rice-wheat rotation system,there were variations in the basic soil prop-erties in the study area at different soil depths.For example,the contents of TOC and TN primarily accumulated in the 0~30 cm depth of arable soils.These were clearly higher than those in the 30~100 cm soil layer.TP content was not remarkably different at different soil depths.Obvious CaCO3 alluvial horizons were also noted in some soil profiles.In the 0~30 cm depth of arable soils,Pb,Cu and Zn contents were similar to that of background soil value.However,Cd content was evidently higher than that of background soil value.Also the average content of the heavy metals was still within WHO threshold,and far below that of China for agricultural soil quality.Factor analysis showed that the sources and transfer characteristics of Pb,Cu and Zn were similar.Cd sources and transfer characteristics were distinct from those of other heavy metals,which was attributed to fertilizer broadcasting and other agricultural factors.While surface accumulation of total Cu and Zn in the soil profiles was obvious,Pb accumulation was not so variable among different soil layers.However,Cd was highly variable at different soil depths.The distribution trends of the heavy metals across the different soil layers were significantly related to heavy metal property,soil profile characteristics and agricultural activity.Cu and Zn were mainly organic and residual fractions in soil profiles.The fraction of residual and organic and Fe/Mn oxide forms were also in relatively high percentages.Total Pb and the associated organic fractions exhibited similar vertical distributions.However,Cd and the associated carbonate and exchangeable forms accounted for considerable percentages.This suggested that Cd was highly mobile in soils and therefore posed potential risks for human health.
Arable land
Soil test
Soil horizon
Cite
Citations (0)
To understand the condition of soil organic matter contents in two counties and two districts of Zhangjiajie,250 samples were taken by the method of S-distribution from representative soil types and their organic matter contents were determined by the potassium dichromate-volumetric outside heating method.The results showed that the soil organic matter contents had significant differences between areas,and the total soil organic matter content ranged from 7.20 to 51.16 g/kg,in which the variation scope of soil organic matter content ranged from16.00~51.60 g/kg.The differences in Wulingyuan District was the biggest,and the next was in Sangzhi county that ranged from 11.10 to 39.90 g/kg;the content variations in Yongding and Cili county were less,ranging from 7.23~36.30 g/kg and from 7.50~32.00 g/kg respectively.The different soil types had a big influence on soil organic matter content,among which the calcareous soil had the highest soil organic matter content,average content of 36.30 g/kg,the lowest was purple soil and brown soil in mountain area,their average content were 16.07 g/kg and 16.10 g/kg respectively.Additionally,there was 62.40% soil in which the organic matter content ranged from 20~30 g/kg.The object of this study was to provide a theoretical basis for protection and utilization the limited soil resources.
Soil test
Cite
Citations (0)
Based on field soil survey and lab test,contents of available Zn,Cd and their relations to organic matter(OM) and pH values in forest soils of northern,eastern and western parts of Guangdong and Pearl River Delta region were studied and relations between available Zn,Cd and pH,OM were analyzed.Results showed that available Zn and Cd contents in the A horizons of the forest soils were 2.770 and 0.045 mg·kg-1,respectively,and those in the B horizon were 1.071 and 0.013 mg·kg-1,respectively,the latter significantly lower than A horizons.Mean contents of available Zn and Cd in forest soils of northern Guangdong were the highest,followed by those in eastern Guangdong,Pearl River Delta region and western Guangdong in a decreasing order.Contents of available Zn and Cd were found to be significantly positively correlated with OM contents in both A and B horizons,and significantly negatively correlated with pH values in B horizons.
Soil survey
Field survey
Soil test
Cite
Citations (0)
Investigation on the agricultural soils under different utilization pattern in Shangqiu City,Henan Province was carried out to clarify the accumulation characteristics of heavy metals in agricultural soils through the analysis of heavy metal content of agricultural soil samples collected in this region. Results indicated that heavy metal content in soils accumulated to some degree,and the mean values of arsenic( As),cadmium( Cd),copper( Cu),lead( Pb) and zinc( Zn) content were 10. 74、0.24、21.87、15.33、70.93mg kg- 1,respectively. In comparison with different agricultural soils under different utilization patterns,the highest content of As,Cu,and Zn occurred in greenhouse vegetable land under protected cultivation,the highest contents of Pb and Cd were found in greenbelt area and orchard soils,respectively,and the least content of heavy metals appeared in forest soils. The content of Cu and Zn in greenhouse vegetable soils were significantly higher than those of forest soils as control( P 0. 05). Relatively lower lead content was found out in greenhouse vegetable land and green belt land. The Cd content in agricultural soils with different utilization patterns ranked in the order of orchard open vegetable land greenhouse vegetable land under protected cultivation green belt land wheat field forest soil. Under intensive production mode,heavy metal content of As,Cd,Cu,Pb,and Zn all increased to some degree with the cultivation year prolonged and corresponding environmental risk increased. Heavy metal accumulation in greenhouse vegetable land was closely related to incorrect input of chemical fertilizer and manure. This study provides a scientific basis for advoiding the risk and preventing the accumulation of heavy metals in soils of region.
Orchard
Cite
Citations (0)
The contents of medium and trace elements in 3288 representative farmland soil samples collected from Xianju county of Zhejiang province were determined.The results showed that: the average exchangeable calcium content was 3.2 mg/kg,which was deficient;the average available sulphur content and the available copper content were 30.16 mg/kg and 1.17 mg/kg,respectively,which were abundant;the average available manganese content was 30.23 mg/kg,which was basically deficient;the average water-soluble boron content was 0.58 mg/kg,which was moderate.The variation coefficients of soil available manganese,available copper and water-soluble boron contents were higher,being 71.9%,70.1% and 60.3%%,respectively.
Trace element
Cite
Citations (0)
Soil properties and heavy metal contents of agriculture soils in Kunshan county were studied for relationships between soil properties and contents of soil heavy metals. Results showed that almost all the soil samples collected from Kunshan Area were of loamy soil with an average pH value being 6.50,an average content of organic matter being 30.53 g/kg and CEC being 17.51cmol/kg,but three parameters did not vary much from site to site; in terms of total content of the major heavy metal pollutants,Cd,Pb and Hg,in the soils of that region,the four types of soils were in the decreasing order of Huangni soil Qingni soil Qingzi soil Wushan soil; and the results of correlation analysis showed that relationships between soil heavy metals and soil physical and chemical properties were very complicated.
Soil test
Cite
Citations (16)
Through the analysis in the paddy soils in Anhui province,the magnesium(Mg) content and its Causal factors were studied.The results were as follows:(1) The total magnesium(T-Mg) contents of the tested paddy soils ranged from 1.86 g/kg to 5.40 g/kg,with an average of 3.11 g/kg which was lower than the average Mg content of farm soils in South China.The exchangeable Mg(Ex-Mg) content of the tested paddy soils was 284 mg/kg in average which showed that the Mg supply capacity of the studied paddy soils was higher.The acid soluble Mg(Acid-Mg) was 2.04 g/kg in average.(2) There had been remarkable defference in the Mg contents derived from different parent materials of Anhui province.The Mg contents in the paddy soils derived from Huaihe river alluvium and Changjiang river alluvium were higher than that derived from river deposition and drift deposit.(3) The soil pH value,clay contents and readily available potassium were major factors affecting Mg content.(4) There had been remarkable correlations between Mg contents of rice plant and soil Ex-Mg,Acid-Mg,T-Mg,which showed that the bioavailabilities of Ex-Mg,Acid-Mg,T-Mg in the studied paddy soils were higher.
Cite
Citations (0)
The soil nutrient contents under different previous land use, tree species and management conditions in Taizishan were analyzed in this paper. Results showed that the soil was acidic, most of the main mineral elements and organic materials were in good conditions. The contents of N(2.64 g/kg), K(171.65 mg/kg) and organic material(2.33%)were high, but the coefficient of the variation of K was large(105%), the contents of P(6.37 mg/kg) and Ca(196.84 mg/kg)were at extremely low levels. The contents of P and K were distinct among different land use soil. It showed that P and K of greenhouse soil were the highest, followed by farm land soil, while the field nursery soil was at lowest level. Most of the soil nutrients among different species nurseries and 18-25 year planted forests had no significant difference and there was the same result among each field nursery.
Soil nutrients
Soil test
Cite
Citations (0)
An investigation study was conducted to analyze available silicon contents(SiO2)of 747 soil samples in nine counties(cities,districts) of Ningbo city,Zhejiang province and to determine the effects of land utilization,soil types,topography and soil chemical properties on available silicon contents in the soils.The results indicated that available silicon content in the cultivated soils averaged 68 mg·kg-1 and the soil samples with rich(≥130 mg·kg-1),medium(100-130 mg·kg-1),deficient(50-100 mg·kg-1),and very deficient levels(50 mg·kg-1) accounted for 15.8%,5.5%,19.8% and 58.9% of total soil samples,respectively.The average silicon contents in upland soils(95 mg ·kg-1) were higher than that in paddy soils(61 mg·kg-1) and the soils with deficient silicon accounted for 58.8% and 83.5% of their total soil samples,respectively.Available silicon contents in different soil types decreased in the order: coastal saline soil(133 mg·kg-1) fluvio-aquic soil(110 mg·kg-1) paddy soil(61 mg·kg-1).Among paddy soils tested,the highest available silicon content(88 mg·kg-1) was obtained from percogenic paddy soil,and the lowest available silicon content(49 mg·kg-1) was obtained from submergic paddy soil.Available silicon contents in different landscape types decreased in the order: coastal plain water-net plain valley plain hills and mountains.Available silicon contents in the soils were significantly correlated with pH and organic matter contents in the soils(P0.01),and were not significantly correlated with available phosphorus and potassium contents in the soils.Aiming at the present situation of serious deficient silicon in Ningbo city,the corresponding recommendations of application of silicon fertilizer were put forward.
Cite
Citations (3)
This paper has used both element geochemistry theory and method to study the characteristics of the soil environment and applied the single pollution index and comprehensive pollution index to evaluate the environment quality of agricultural soil in Weishe Town,Bijie City,Guizhou Province.The main research results are as follows:modern agricultural soil in Weishe Town is of weak acidity,and its pH value varies between 5.10 ~ 7.38 with the mean value of 6.12;soil organic matter is very abundant and the contents are between 3.29% ~ 12.06%,with the mean value of 5.85%;the contents of total N,total P,total K in the study area are between1735 ~ 6325 mg / kg,667.2 ~ 1579.69 mg / kg,5016.06 ~ 15063.03 mg / kg,with the mean values of 3722 mg / kg,1161.4 mg / kg,and 9186.2 mg / kg,respectively.According to the Classification Standard of the Nutrient Grading of National Second Soil Survey,total N and P in the study area are of the first class,which needn't to be added.However,total K is at the fifth class which needs to be added in order to increase soil fertilization.The contents of Ca and Mg in the study area are lower than the average content in Guizhou Province,which should be added properly.The contents of the harmful heavy metals Cr,Cd,As and Pb in the surface soil are characterized as being Cr Pb As Cd and the contents of Cr and Cd are higher than the average content in Guizhou Province,but the contents of As and Pb are lower than this value.From the single-factor pollution evaluation results,we can see that heavy metal Cd has become the most serious contaminant material in the agricultural soil,followed by Cu,Ni and Zn.The comprehensive pollution index indicates that most of the soil have been seriously polluted.Cd and Zn mainly come from the extraneous source pollution and most of them are concentrated in the surface soil,which has caused a great risk to agricultural production.
Soil test
Mean value
Soil Quality
Cite
Citations (0)