The profile distribution of total and extractable copper in selected Nigerian soils

Abstract

The profile distribution of total, DTPA‐ and 0.1N HCl‐extractable Cu was determined in 11 Nigerian soil profiles formed from various parent materials including the coastal plain sands, shales, basalt, granite and banded gneiss.

Total Cu ranged from 7 to 72 ppm with a mean of 35 ppm₀ The soils formed from basalt had the highest values while those on coastal plains had the least content. Generally, there was a higher content in the subsoils than in the surface horizons. The total Cu significantly correlated with percent clay and the free oxide contents of Fe and Mn.

DTPA ‐ and 0.1N HCl‐extractable Cu ranged from 0.08 to 2.81 ppm and 0.10 to 7.78 ppm, respectively. Soils on metamorphic rocks gave the highest values of DTPA‐extractable Cu. The DTPA‐extractable Cu ‐was only related to pH but the acid extractable Cu was associated with total Cu, clay, free Fe₂O₃ and MnO₂ contents.     

The profile distribution of total and extractable zinc in selected Nigerian soils

Abstract

The profile distribution of total, DTPA‐ and 0.1 N HC1‐extractable Zn was determined in 11 Nigerian soil profiles formed on various parent Materials including the coastal plain sands, shales, basalt, granite and banded gneiss.

The total content ranged from 9 to 84 ppm. Generally soils developed on igneous rocks contained more Zn than those on sedimenatary deposits. Among the soils on sedimentary rocks, those on shale had more total Zn than those on sandstones. Total Zn was weakly correlated with organic matter but strongly associated vith clay content and free oxides of iron and manganese.

The amounts of Zn extracted by DTPA and 0.1 N HC1 ranged from 0.01 to 10.98 and from 0.23 to 6.25 ppm, respectively. The dilute acid generally removed more Zn from the soils than did the DTPA. The amounts extracted generally decreased vith depth especially vith DTFA extractant. Soils developed on basalt and shales contained the highest amounts of 0.1 N HCl‐extractable Zn while those on basement complex rocks gave the highest values of DTPA‐extractable Zn. Extractable Zn from soils on coastal plain sands remained relatively lev. The extractable Zn was more associated vith organic matter than vith clay content.     

印度酸性耕作土中总锰、铁以及可提取态锰、铁的水平、分布及其与土壤性质的关系研究

A total of 400 surface soil(0–15 cm) samples were collected from cultivated soils representing four soil series,namely,Hariharapur,Debatoli,Rajpora and Neeleswaram in Orissa,Jharkhand,Himachal Pradesh and Kerala states of India,respectively,and were analyzed to measure the contents of total and extractable Mn and Fe,to establish the relationship among total and extractable Mn and Fe and soil properties,and to characterize the spatial distribution pattern of Mn and Fe in some cultivated acid soils of India. The contents of total as well as extractable Mn and Fe varied widely with extractants and soil series. However,the amounts of Mn or Fe extracted by diethylene triamine penta-acetic acid(DTPA),Mehlich 1,Mehlich 3,0.1 mol L-1 HCl and ammonium bicarbonate DTPA(ABDTPA) were significantly correlated with each other(P 0.01). Based on the DTPA-extractable contents and the critical limits(2 mg Mn kg-1soil and 4.5 mg Fe kg-1 soil) published in the literature,Mn and Fe deficiencies were observed in 7%–23% and 1%–3% of the soil samples,respectively. The content of soil organic carbon(SOC) had greater influence on total and DTPA-extractable Fe than did soil pH. Geostatistical analysis revealed that total and DTPA-extractable Mn and Fe contents in the acid soils were influenced by soil pH,SOC content,and exchangeable cations like potassium,calcium and magnesium. Spatial distribution maps of total and DTPA-extractable Mn and Fe in soil indicated different distribution patterns.     

Influence of extractable iron,aluminium, and manganese on P-sorption in flooded acid sulfate soils

We evaluated the effect of 1 N NH₄OAc and sodium-citrate dithionite extractable forms of soil Fe, Al, and Mn on P-sorption of a flooded acid sulfate soil (Sulfic Tropaquepts) and a non-acid sulfate soil (Typic Tropaquepts) under different soil oxidation-reduction and pH conditions. We used Maha-Phot soil (Sulfic Tropaquepts) and Bangkok soil (Typic Tropaquepts) from the Bangkok Plain, Thailand, and incubated them with 0.2% rice straw under aerobic (O₂ atmosphere) and anaerobic (N₂ atmosphere) conditions at three different levels of pH (4.0, 5.0, and 6.0) for 6 weeks in stirred soil suspensions with a soil to 0.01 M CaCl₂ solution ratio of 1:7. After the incubation period, the soil suspensions in the first treatment (control) were not washed or pretreated with any extractants. For the second treatment (II), the soil suspensions were treated with 1 N NH₄OAc (buffered to pH 4.0) to remove Fe, Al, and Mn in exchangeable form. In the third treatment (III), the soils suspensions were treated with sodium citrate dithionite solution (20%) to remove Fe, Al, and Mn in the form of free oxides. The soil residues were then equilibrated with KH₂PO₄ ranging from 0 to 500 mg P kg^-1 soil. Sorption isotherms were described by the classical Langmuir equation. The P-sorption parameters under study were standard P requirement (SPR), Langmuir maximum sorption capacity (X _m), Langmuir sorption constant (k), and buffering index (BI). Treating soils with 1 N NH₄OAc reduced X _m by 32–55%, SPR by 68–84%, and also decreased the differences in P-sorption due to the effects of pH and oxidation-reduction conditions. Significant correlations between the P-sorption parameters and the amount of free iron oxides indicated the primary role of iron oxides in P-sorption of acid sulfate soils. Aluminium oxides seemed to play a secondary role in P-sorption of these soils. Manganese also showed an important effect on P-sorption, but the mechanism is ambiguous.This is a contribution from the Wetland Biogeochemistry Institute, Louisiana State University, Baton Rouge, LA 70803-7511     

Available and total forms of copper and zinc in basaltic soils of the Nigerian Savanna

Abstract

The available (0.1M HCl‐ and DTPA‐extractable) and total forms of copper (Cu) and zinc (Zn) were determined in soils developed on various groups of basalts, namely, the Newer, Older, Lateritized‐Older, and Biu (undifferentiated) basalts. The HCl‐, DTPA‐extractable, and total Cu in the soils ranged from 0.40 to 5.60, 0.15 to 2.64, and 15 to 65 mg Cu kg^‐1, respectively, with corresponding means values of 2.06, 0.89, and 41 mg Cu kg^‐1. Similarly, HCl‐, DTPA‐extractable, and total Zn varied from 3.00 to 6.20, 0.14 to 2.15, and 25 to 265 mg Zn kg^‐1 with respective mean values of 4.65, 0.52, and 89 mg Zn kg^‐1. The soils were high in the total forms of Cu and Zn, generally sufficient in available Cu, but deficient in available Zn. Both the total and available forms of Cu and Zn were little correlated with soil properties in soils of the Lateritized‐Older and Biu basalts, while only the available forms were related mainly to silt, clay, pH, and organic carbon in soils of the Newer and Older basalts. Furthermore, the available forms were correlated with each other, but not with the total forms.     

Distribution of total and extractable forms of iron,manganese, and aluminum in development of rice soils of saga polder lands

The distribution of pedogenic oxides of Fe, Mn, and Al was described for rice soils of Saga polder lands and its relationship to soil development with time was investigated. The distribution of Mn largely parallelled that of Fe and in response to the soil development their accumulation occurred in the B horizons of the profiles. Manganese was the clement most susceptible to downward movement, which lad to a pronounced lowering of extractable Mn content in the surface horizons in well-developed soil morphology. By contrast, this is not the case for Al which, in general, had little change in extractable Al and a slight increase in total Al with depth as the time increased. Apparently the distribution of Mn was largely governed by the extent of reduction processes, whereas in the Al distribution clay migration may be a principal controlling factor. The distribution of Fe may be due chiefly to the reduction processes, with some contribution from the clay migration.     

Soil and crop responses to different tillage practices in a ferruginous soil in the Nigerian savanna

Mechanical tillage is gaining prominence as a food production technique in the savanna region of Nigeria. A mechanical cultivation method was compared with a zero cultivation practice and the traditional cultivation method involving a hoe.Soil moisture content was significantly higher (P = 0.05) under zero tillage than under mechanical tillage or traditional hoe tillage systems. The stability of aggregates less than 2-mm diameter and the mean equilibrium infiltration rates were significantly lower under mechanical tillage. No significant differences were found between zero tillage and manual tillage. Soil bulk densities in the 0–5-cm depth under zero tillage were significantly higher than under the other tillage systems due to the greater disturbance of soil in the latter. Below the 0–5-cm depth, differences in bulk densities between tillage treatments were not significant.Nutrient ion distribution in the soil varied with the tillage system. Total P and K levels were higher in the surface than in the sub-surface soils under zero tillage, but not under the other tillage systems. Mean maize grain yields (kg ha⁻¹) and cotton lint yields (kg ha⁻¹) under the 3 tillage systems were not significantly different (P = 0.05). However, significant yield differences were observed in some years. Weed population was significantly greater (P = 0.01) under zero tillage than under mechanical tillage.     

Tolerance of limpograss (PI 364344) to excess manganese in acid soil and nutrient solution

Previous studies showed that limpograss, Hemarthria altissima (Poir), Stapf & C. E. Hubb (PI 364344) was tolerant to low temperature and to high concentrations of Al in acid soil, mine spoil and nutrient solution. Additional experiments were conducted to test the tolerance of this limpograss clone to excess Mn, another potential growth‐limiting factor in acid soils.

Cuttings from a single plant were grown in pots of Mn‐toxic Zanesville soil with no lime (pH 5.1) and 1250 ppm CaCO (pH 6.3) and in nutrient solutions containing 0, 4, 8, 16, 32 or 64 ppm Mn at pH 4.0. The grass was highly tolerant to excess Mn in both media. Liming the soil from pH 5.1 to 6.3 did not significantly affect top dry weight of the first harvest and significantly decreased that of the second. In nutrient solutions at pH 4.0 top dry weights were not significantly affected by Mn concentrations up to 64 ppm. Root dry weights were significantly increased by Mn additions of 16, 32 and 64 ppm. Limpograss (PI 364344) was not injured when Mn concentrations were as high as 930 and 9152 ppm in tops and roots, respectively. High Mn tolerance is yet another trait that should enhance the potential use of this grass in revegetating acid mine spoils and other acid sites.     

Comparison of phospholipid fatty acid (PLFA) and total soil fatty acid methyl esters (TSFAME) for characterizing soil microbial communities

Phospholipid fatty acid (PLFA) and total soil fatty acid methyl esters (TSFAME), both lipid-based approaches used to characterize microbial communities, were compared with respect to their reliable detection limits, extraction precision, and ability to differentiate agricultural soils. Two sets of soil samples, representing seven crop types from California's Central Valley, were extracted using PLFA and TSFAME procedures. PLFA analysis required 10 times more soil than TSFAME analysis to obtain a reliable microbial community fingerprint and total fatty acid content measurement. Although less soil initially was extracted with TSFAME, total fatty acid (FA) content g⁻¹ soil (DW) was more than 7-fold higher in TSFAME- versus PLFA-extracted samples. Sample extraction precision was much lower with TSFAME analysis than PLFA analysis, with the coefficient of variation between replicates being as much as 4-fold higher with TSFAME extraction. There were significant differences between PLFA- and TSFAME-extracted samples when biomarker pool sizes (mol% values) for bacteria, actinomycetes, and fungi were compared. Correspondence analysis (CA) of PLFA and TSFAME samples indicated that extraction method had the greatest influence on sample FA composition. Soil type also influenced FA composition, with samples grouping by soil type with both extraction methods. However, separate CAs of PLFA- and TSFAME extracted samples depicted strong differences in underlying sample groupings. Recommendations for the selection of extraction method are presented and discussed.     

Modification of soils in Nigerian savanna by soil-feeding Cubitermes (isoptera,termitidae)

Soil-feeding termites ingest humified, organic-rich soil. The soil faeces are used for nest construction and mounds of two species of Cubitermes contained more soil, clay, exchangeable Ca and Mg, available P, total N and organic C than adjacent topsoil. Available P increased by 1.4–6.0 times. Mounds of a plant-debris feeding termite, Trinervitermes, contained significantly more of these fractions, with the exception of available P, than adjacent topsoil. The modification of Trinervitermes mounds by Cubitermes resulted in a 2-fold increase in available P, whereas organic C remained the same and N increased by 1.5-times. The relatively large increase in available P resulting from soil feeding termites could be attributed to the high pH regime in their hind-guts.     

Comparison of 0.1N sodium hydroxide with 0.1M sodium pyrophosphate in the extraction of soil organic matter from various soil horizons

Abstract

Soil samples representing the O, A, B, and C soil horizons from soil organic matter (SOM) studies were selected to study the relative effectiveness of 0.1N sodium hydroxide (NaOH) and 0.1M sodium pyrophosphate (NaPyr) in extracting organic carbon (OC). Replicate samples were extracted with each extractant in a ratio of about 1:144 and successive extractions were performed for each soil. Results indicated the importance of successive extractions for more complete removal of extractable OC. A single extraction removed an average of only 68%, 78%, 86%, and 60% of the OC extracted with four successive extractions for the O, A, B, and C horizons, respectively. The C horizons were lowest in OC and the slowest to release OC in the extraction process. Organic C was solubilized from the B horizons most quickly with an average of 95% of the successively extractable OC removed with only two extractions. The extractability of the soil TOC was highest in the Bhs and then the Bw, C, A, and O horizons at 92% and 42%, 46%, 38%, and 3 6%, respectively. The NaOH and NaPyr were nearly equal in extracting OC from the Bhs horizons. The NaOH extracted more OC than the NaPyr at 53%, 55%, 29%, and 47% more in the O, A, Bw, and C horizon samples, respectively. These results stress the importance of considering the soil horizon type and the use of NaOH in successive extraction for maximum removal of OC in soil studies.     

Comparison of water,ammonium acetate,and dtpa to assess the availability of manganese in peat substrate

Abstract

An experiment was conducted to assess the suitability of three extractants, water (press‐extract and 1:1.5 volume‐extract), 0.5 M ammonium acetate (NH₄OAc) and 0.005 M DTPA for determining plant available manganese (Mn) in peat substrates. Chrysanthemum morifolium was used as a test crop. Substrates were selected for differences in Mn‐content: moss peat with 0, 15, and 30% Mn‐rich clay. The three substrates with each four levels of Mn‐addition were compared. Manganese in the water‐extracts correlated well with the Mn in the plant. Poor correlations of Mn‐NH₄OAc and Mn‐DTPA versus Mn in the plant were found, caused by the fact that the clay increased the Mn‐DTPA and Mn‐NH₄OAc, but not Mn in the plant. The clay contained Mn which was not available. Only the water‐extracts could be used to assess the availability of Mn. The correlation coefficients of Mn‐DTPA versus Mn‐NH₄OAc, of Mn‐DTPA versus Mn‐press‐extract, of Mn‐1:1.5 volume‐extract versus Mn‐NH₄OAc, and of Mn‐1:1.5 volume‐extract versus Mn‐DTPA were low. Only Mn‐1:1.5 volume‐extract versus Mn‐press‐extract and Mn‐NH₄OAc versus Mn‐press‐extract gave high correlation coefficients.     

长江三角洲地区土壤盐酸可提取态重金属含量的空间变异特征

以江苏昆山市为典型区,对长三角地区土壤盐酸可提取态重金属含量的结构特征进行分析,得出该区盐酸可提取态重金属的空间分布格局并揭示了引起这种分布格局的成因和污染来源,结果表明：昆山市盐酸可提取态Cd、Cr、Cu、Pb、Zn、Hg属强变异,Ni和Co为中等变异。半方差函数模型拟合表明所有盐酸可提取态重金属元素均符合球状模型,8种重金属元素在一定范围内均存在空间相关性。采用Kriging最优内插法得到了盐酸可提取态重金属含量的空间分布格局,表明土壤盐酸可提取态重金属含量与工业活动、污水灌溉和大气降尘密切相关。通过主成分分析与地统计学相结合的方法,得出该区盐酸可提取态重金属由4个主成分构成,第一主成分为Cd、Cu、Pb、Cr和Zn,决定这一成分的主要因素为工业污水灌溉、大气降尘和元素地球化学特征;第二主成分为Ni,决定这一成分的主要因素为土壤内部因子;第三主成分为Hg,该成分主要受工业点源污染的影响;第四主成分为Co,该成分可能主要受地形影响。     

淹水还原条件下红壤中葡萄糖及腐殖酸对铁锰形态的影响

通过设置不同的葡萄糖/腐殖酸配比模拟还原性土壤体系,考察长期(约74 d)淹水培养过程中铁锰元素在土壤溶液/矿物相中的分布形态演变。结果表明:在淹水培养初期,葡萄糖的添加可以促进铁锰离子的还原溶出,同时土壤中可交换态和酸可提取态铁、以及可交换态锰的含量也会随之增加;而腐殖酸的添加则会促进土壤中可氧化态铁/锰含量的升高。随着培养时间的增加,铁锰离子浓度及各个土壤提取形态的铁锰含量大多呈现降低趋势,铁锰元素逐渐转化成提取性更低的矿物形态。因此,淹水环境中铁锰还原溶出-分布形态演变受到土壤中有机物质种类和含量的显著影响,呈现出不同的金属移动性和生物有效性。     

The variation of ferrous iron content and soil profiles under flooded condition of rice field (Part 1)

Rice fields are kept under flooded condition during the growing period of rice plant for at least three months. Soil of rice fields therefore shows consequently remarkable differences as compared with that of upland fields. This may be understood as a kind of redoxy system. Many soil constituents suffer big changes during floodtime. One of the most important constituents is iron because of its abundance in soil and its color change.     

Effects of HC1 acid and lime amendments on soil ph and extractable Ca and Mg in a sandy soil

Abstract

High vater table sandy soils present special problems when establishing soil pH variables under field conditions. In order to examine the response of a coarse‐textured soil to lime and HC1 acid treatments, data are reported for soil pH and extractable Ca and Mg for a field experiment where Mn treatments on soybeans was the primary objective. Three treatments included HC1 acid, control, and lime. Acid (742 liters/ha 3N HC1) was added only at the beginning of the experiment but dolomitic lime treatments were added each year (2240, 2740, and 2900 kg/ha). The lime and acid were applied to the soil surface and incorporated to a depth of 10 to 13 cm. Soil samples were taken every 2 to 3 months at 3 depths (0 to 15, 15 to 30, and 30 to 45 cm) and analyzed for pH and extractable Ca and Mg. Acid treatment decreased the pH by 0.2 units below the untreated soil at the 0 to 30 cm depth and the effect lasted the entire 3 years of the study. Calcium values were lowered only slightly by the acid treatment. Lime additions caused steady increases in soil Ca. Magnesium values increased several months after each of the first and second lime applications. Lime raised the subsoil (30 to 45 cm) pH after 4 to 6 months. Seasonal variations in pH were very wide with the untreated soil pH varying from 6.1 to 6.8. The high pH level of 7.0 was not maintained for an entire season until the third year of the experiment. Soil pH as well as extractable Ca and Mg showed fluctuations that were the result of seasonal variations and soil moisture content at the time of sampling. Soil pH variables on a sandy soil should be established at least a year in advance of starting an experiment and must be closely monitored in order to maintain the desired pH levels.     

Distribution of iron and manganese oxides in Haploxeralfs and Rhodoxeralfs and their relation to the degree of soil development and soil colour

The status and the distribution of iron and manganese oxides were studied in six soil profiles from Thrace region (Greece), classified as Rhodoxeralfs and Haploxeralfs. The acid ammonium oxalate and the dithionite-citrate-bicarbonate methods were used to extract the free iron and manganese oxides from the soils. In both great groups the Fed and Mnd values are higher than Feo and Mno values, respectively, indicating that a considerable fraction is present in crystalline form. Both Feo/Fed and Fed-Feo values suggest that, in the study area, Haploxeralfs are less developed soils than Rhodoxeralfs. The manganese oxides present in crystalline forms (Mnd-Mno) were more in Rhodoxeralfs than in Haploxeralfs, suggesting that the crystallinity of manganese oxides increases, with the degree of soil development. Significant correlations were found of Redness Rating to Fed-Feo and to Feo/Fed ratio, positive and negative respectively, leading to the conclusion that soil red colouration increases with the degree of soil development.     

Changes in bulk precipitation reactivity throughout the vegetation/soil continuum in a Trachpogon savanna (Venezuela)

Abstract

The reactivity of bulk precipitation moving into the soil of a bush island Trachypogon savanna throughout a forest grove and the herbaceous layer was analyzed during four consecutive years. In the forest grove, there was a significant decrease of annual hydrogen (H⁺) content (meq/ha) of 44–75% as rainfall leached through the canopy, whereas the bulk throughfall pH in the grass layer was similar to the bulk precipitation pH. As throughfall passed throughout the soil profile of the grove, the H⁺ content decreased 87–70%. Results evidenced a buffering capacity of the system when bulk precipitation was acid during the last measured year. The savanna system retained 92–93% of H⁺ input from the bulk precipitation indicating that a redistribution of H⁺ ocurred instead of a net input or net loss. Canopy neutralization of bulk precipitation appears to take place in the grove canopy mainly by organic and bicarbonate salts.     

Movements of free oxides in paddy soil profiles (Part 1)

In this paper, the results of observations of soil profiles and the investigations of movements of free oxides in two soil types of dry paddy fields Which carry barley or wheat in the period of winter crops are set forth. Their parent materials are charty somewhat accompanied with shales and granite, and in Soil A and B a small quantity of volcanic ash is contained. The structure develops Well in all the soils.     

Effect of manganese and soil pH on the iron content of crops grown on podzol soils

In a greenhouse study on three podzol soils with pH values of 5.4–5.6, liming to pH 7.6 or higher decreased the Fe concentration of pea plant tissues from 47 to 42 ppm. In the case of barley, liming the soil increased the mean tissue Fe concentration from 104 to 119 ppm at pH 7.6 and to 107 ppm at pH 7.7. Field experiments on wheat, oats, alfalfa, and timothy showed that Mn applied to the soil or as foliar spray did not affect the Fe concentration of cereal or forage plant tissues. Liming did not affect the Fe concentration of cereal kernels but on a few locations it increased the Fe concentration of the boot stage tissue. The Fe concentration in oats was higher than that in wheat. Based on the results of a survey, it was found that forage legumes contained more Fe than did timothy. The survey also showed that a few Fe values in timothy and cereals would be considered low, although Fe deficiency has not been experienced in this region. A number of the samples would be in the deficiency range from the animal nutrition standpoint.