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.     

Influence of residual phosphate fertilizer on labile and extractable zinc in hawaii soils

Abstract

Zinc availability was studied using five soils from Hawaii which had histories of massive phosphorus applications. Heavy phosphate fertilization usually increased extractable Zn, irrespective of the extractant used. The extra extractable Zn associated with the added P probably came from Zn as an accessory element in the fertilizer. Treble superphosphate commonly used in Hawaii contains about 1400 ppm Zn. The Zn content of phosphate fertilizers must be considered before making statements about the effect of fertilizer P on Zn solubility and availability in soils.

Two solutions (0.1N HCl and 0.005M DTPA) were compared as Zn extractants for Hawaii soils. DTPA extracted less Zn than 0.1N HCl. Zinc extracted by repeated HCl treatment was more closely related to the labile Zn pool (E‐values and L‐values) than was DTPA‐extractable Zn. The results suggest that 0.1N HCl extractable Zn, Zn E‐value and Zn L‐value measured the quantity of a single fraction of soil Zn.

Repeated extraction of soil with 0.1N HCl seems to be a suitable procedure for evaluating the Zn status of acid, highly weathered soils of Hawaii.     

Etude de la nutrition potassique du sorgho II‐ incidence du remplacement du potassium par le sodium sur la teneur en acides organiques des feuilles

Abstract

An Investigation was conducted to determine the content and distribution of total and DTPA‐extractable Zn in the genetic horizons of 72 agriculturally important soils from the six major mineral soil areas in Louisiana.

The concentration of total Zn appeared to vary more with the clay constituents of the soils and the amount of the element in the parent materials than with soil depth. The majority of the soils had the largest amounts of total Zn in the subsurface horizons. The range in total Zn for all soils and horizons was from 7.0 to 150.0 ppm.

The DTPA‐extractable Zn in all of the soils and horizons ranged from 0.08 to 4.22 ppm. In the majority of the soil profiles the highest concentration of extractable Zn was in the surface horizons. There was a decrease in the extractable Zn with increasing soil depth. The alluvial soils along the Ouachita and Mississippi Rivers, and the Mississippi Terrace soil areas contained relatively large amounts of DTPA‐extractable Zn.

In some soils the extractable Zn significantly correlated with total Zn. There was also a close relationship between extractable Zn and organic matter content, especially in the Ap horizons.     

Distribution of Forms of Zinc and Their Association with Soil Properties and Uptake in Different Soil Orders in Semi‐arid Soils of Punjab,India

Abstract

Profiles of semi‐arid–zone soils in Punjab, northwest India, were investigated for different forms of zinc (Zn), including total, diethylenetriamine penta‐acetic acid (DTPA)-extractable, soil solution plus exchangeable (Zn), Zn adsorbed onto inorganic sites, Zn bound by organic sites, and Zn adsorbed onto oxide surfaces. Irrespective of the different fractions of Zn present, its content was higher in fine‐textured Alfisols and Inceptisols than in coarse‐textured Entisols. In general, the higher content of Zn was observed in the surface horizon and then decreased in the subsurface horizons. However, none of the forms of Zn exhibited any consistent pattern of distribution. Organic matter and size fractions (clay and silt) had a strong influence on the distribution of different forms of Zn. Based upon the linear coefficient of correlation, the soil solution plus exchangeable Zn, adsorbed onto inorganic sites, and DTPA‐Zn increased with increase in organic carbon but decreased with increase in pH and calcium carbonate content. Total Zn increased with increase in clay and silt content. Among the different forms, Zn bound by organic sites, water soluble plus exchangeable Zn and Zn adsorb onto oxide (amorphous surfaces) were all correlated with DTPA extractable Zn. The uptake of Zn was more in recent floodplain Entisols than very fine textured Alfisols and Inceptisols. Among the different forms soil solution +exchangeable and DTPA‐extractable Zn was positively correlated with total uptake of Zn.     

Soil micronutrient contents and relation to other soil properties in Ethiopia

Abstract

Alfisols, Vertisols, Inceptisols, Aridisols, Mollisols, and Entisols were sampled (0–30 cm) from 32 locations across Ethiopia. The soils were analyzed for copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe) contents using 0.005 M diethylene triamine pentaacetic acid (DTPA), 0.05 M hydrochloric acid (HC1), and 0.02 M ethylene diamine tetraacetic acid (EDTA) extractants. EDTA extracted more of each micronutrient than DTPA, which extracted greater amounts than HC1. The quantities of EDTA and DTPA‐extractable micronutrients were significantly correlated, and were in the order: Mn>Fe>Cu>Zn. The order of HCl‐extractable micronutrients was Mn>Fe>Zn>Cu. Micronutrient contents of Mollisols, Vertisols, and Alfisols were usually greater than those of the other soils, and Entisols usually had the lowest micronutrient contents. The contents were mostly positively correlated with clay and Fe₂O₃ contents, but negatively correlated with soil pH and A1₂O₃contents. While comparison of DTPA‐ and EDTA‐extractable micronutrients with critical levels showed that most soils had adequate amounts of the micronutrients for crops, the amounts extracted by HC1 were below critical levels in most soils. Since the critical levels that were used in the comparisons were not established in Ethiopia, calibration of the soil contents of these micronutrients with crops grown in Ethiopia is required to identify the most suitable extractant(s).     

Distribution of DTPA‐extractable Fe,Zn, and cu in soil particle‐size fractions

Abstract

To examine the distribution of DTPA‐extractable Fe, Zn, and Cu in clay, silt, and sand fractions; surface soils were collected from cultivated fields of North Dakota, South Dakota, West Virginia, Iowa, Ohio, and Illinois. Clay, silt, and sand fractions were separated after sonic dispersion of soil water suspension and analyzed for DTPA‐extractable Fe, Zn, and Cu. In general, clay had the highest and sand the lowest amount of DTPA‐extractable metals. Consequently, clay had the highest and sand the lowest intensity and capacity factors for these metals since DTPA micronutrient test measures both these factors.     

Evaluation of Various Zinc Extractants in Lowland Rice Soil under the Influence of Zinc Sulfate and Chelated Zinc

Field experiments were conducted on rice (cv ‘IET 4094’) in an Aeric endoaquept (pH 7.2) to evaluate the various zinc (Zn) extractants in lowland rice soil under the influence of Zn sulfate and chelated Zn. The diethylenetriaminepentaacetic acid (DTPA), 0.1 N hydrochloric acid (HCl), and 0.05 N HCl‐extractable Zn concentrations in soil increased initially up to the Z29 stage of crop growth when Zn was applied as a single basal source, being greater with Zn ethylenediaminetetraacetic acid (Zn‐EDTA) compared to zinc sulfate (ZnSO₄) application. Among the various extractants, the performance of 0.1 N HCl in extracting Zn was better than the other two extractants and followed the trend 0.1 N HCl > 0.005 M DTPA > 0.05 N HCl. The greatest increase in grain and straw yield of rice was 37.8 and 20.4%, respectively, over the control in the treatment T₇ (1 kg Zn ha^?1 as Zn‐EDTA at basal).     

Evaluation of efficient soil test methods for Zn and their critical vales in salt‐affects soils for rice

Abstract

Soil pot culture experiment was conducted on 22 soils of Balewal‐Phaguwala‐Narike (BPN) and 24 soils of Isri‐Langrian‐Narike (ILN) associations using rice (PR 106) as test crop at 0 and 7.5 ppm Zn levels. Chelating extractants 0.005M DTPA, 0.01M EDTA‐(NH₄)₂CO₃ and 0.05M EDTA, extracted more soil Zn than double‐acid and were significantly correlated with each other as well as with soil pH and clay in BPN and only with clay in ILN soil association. Soil CaCO₃ governed the double‐acid extractable Zn in these soils. Dry matter yield and Zn uptake by rice significantly increased with 7.5 ppm Zn application. The response was higher in ILN than BPN soil association, The DTPA method gave the highest correlation with Bray's yield and Zn uptake (r =0.72 and 0.55) followed by 0.05M EDTA (r ‐ 0.75 and 0.61) or EDTA‐(NH₄)₂CO₃ (r =0.70 and 0.61). The predictability of rice yield improved from 18–27 to 27–35, 32–43, 34–44 and 51–55 percent as a result of stepwise inclusion of pH, CaCO₃, organic carbon (OC) and clay respectively in the regression equation alongwith Zn extracted by chelating agents.

The critical levels of DTPA, EDTA‐(NH₄)₂CO₃ and EDTA extractable Zn significantly differed in the two associations and were 0.69, 0.82 and 1.24 ppm in BPN and O.BC, 1.09 and 1.42 ppm in ILN soil association. Soil properties further affected the critical levels. This for DTPA available Zn was 0.80 and 1.03 ppm in soil containing less and greater than 2% CaCO₃, 1.03 and 0.80 ppm in soils containing less and greater than 0.25% OC. These values for EDTA‐(NH₄)₂CO₃ available Zn were 1.09 and 0.91 ppm Zn in soils containing less and greater than 15% clay suggesting that critical levels of Zn for each category of soil properties should be considered while making recommendations of Zn fertilization of crops.,     

Use of NH4 HCO3‐DTPA soil test to assess availability and toxicity of selenium to alfalfa plants

Abstract

This study was carried out to determine if ammonium bicarbonate‐DTPA soil test (AB‐DTPA) of Soltanpour and Schwab for simultaneous extraction of P, K, Zn, Fe, Cu and Mn can be used to determine the availability index for Se. Five Mollisols from North Dakota were treated with sodium selenate and were subjected to several wetting and drying cycles. These soils were extracted with hot water and with ammonium bicarbonate‐DTPA (AB‐DTPA) solution for Se analysis. Alfalfa plants were grown in these soils in a growth chamber to determine plant uptake of Se. In addition to the above experiment, coal mine soil and overburden materials from Western Colorado were extracted and analyzed as mentioned above.

It was found that hot water and AB‐DTPA extracted approximately equal amounts of Se from Mollisols. A high degree of correlation (r =0.96) was found between Se uptake by plants and AB‐DTPA extractable Se. Extractable level of Se in treated soils was decreased with time due to change of selenate to less soluble Se forms and plant uptake of Se. An AB‐DTPA extractable Se level of over 100 ppb produced alfalfa plants containing 5 ppm or higher levels of Se that can be considered toxic to animals. Soils with about 2000 ppb of extractable Se were highly toxic to alfalfa plants and resulted in plant concentrations of over 1000 ppm of Se. The high rate of selenate (4ppm Se) was less toxic to alfalfa plants in soils of high organic matter content. This lower toxicity was accompanied with lower extractable levels of Se.

The AB‐DTPA solution extracted on the average about 31% more Se than hot water from the mine and overburden samples and was highly correlated with the latter (r =0.92). The results indicated the presence of bicarbonate‐exchangeable Se in these materials.     

The extractable trace element content of acid soils and the influence of pH,organic matter and clay content

Abstract

The analysis of extractable trace elements was carried out on 434 soils using 0.1 N HC1 as the extractant for copper, manganese, iron, zinc and cobalt, 0.2 M ammonium oxalate at pH 3.0 for molybdenum and boiling water for boron. Results indicated that on the average from about 1 to 20 percent of the total element content of the soil uas extractable, the percentage varying with the element. Comparing the amount of extractable elements in the 0–15 cm and 15–30 cm layers indicated that only manganese, zinc and boron were significantly different.

Correlation studies showed that the pH significantly influenced the quantity of manganese, iron, zinc and boron extracted, while organic matter influenced copper, manganese, zinc, cobalt and boron and clay content the copper, manganese, iron, zinc, cobalt and boron.     

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.     

Use of routine soil tests in predicting corn leaf zinc

Abstract

Zinc of index corn leaves samples from 91 Minnesota sites on numerous soil types was correlated with soil Zn extracted by four routine procedures. The EDTA?(NH₄)₂CO₃ ‐ extractable soil Zn was more closely correlated with leaf Zn than soil zinc extracted by 0.1N HCl, EDTA‐NH₄OAc, or by NH₄OAc ‐ dithizone. Soil pH, CaCO₃ equivalent, extractable P, and organic matter of both acid and calcareous soils were negatively correlated with leaf Zn. When EDTA ? (NH₄)₂CO₃ ‐ extractable Zn was included with routine soil tests, a prediction equation for corn leaf Zn was formulated and compared with analytical values. However, the use of 1.4 ppm EDTA ? (NH₃)₂CO₃, ‐ extractable soil Zn alone as a critical value was equally effective in predicting leaf Zn.     

Effect of wetting and drying on DTPA‐extractable Fe,Zn, Mn,and Cu in soils

Abstract

The study reported herein was intended to determine the effect of (i) wet‐incubation and subsequent air‐drying, and (ii) oven‐drying on DTPA‐Fe, Zn, Mn, and Cu.

Analysis of wet‐incubated soils showed significant decreases in DTPA‐Fe, Mn, and Cu at the 1% and Zn at the 10% level of probability. Air‐drying of these moist‐incubated soils increased the levels of Fe, Zn, and Cu to values close to their original levels. Levels of Mn sharply deviated from their original values after air‐drying of incubated soils. Correlation coefficients (r) between the amounts of extractable nutrients in original air‐dry soils and wet‐incubated soils were 0.54, 0.87, 0.91, and 0.13 for Fe, Zn, Cu, and Mn, respectively. Oven‐drying increased the levels of DTPA‐extractable micronutrients from 2 to 6 fold.     

Effect of Olive‐Derived Organic Amendments on Lead,Zinc, and Biochemical Parameters of an Artificially Contaminated Soil

Abstract

An incubation experiment was conducted to ascertain the effects of three olive‐derived organic amendments (fresh, compost, and vermicompost olive cake) on the soluble and diethylenetriamine pentaacetic acid (DTPA)–extractable lead (Pb) and zinc (Zn) and on different enzymatic activities in an artificially contaminated calcareous soil. Application of the compost and vermicompost, which increased amounts of humic acids in soil, initially stimulated dehydrogenase, ß‐glucosidase, and urease activities, which tended to decline afterward. In contrast, dehydrogenase and ß‐glucosidase activities were lower after application of the fresh olive cake. Amounts of soluble Pb and Zn increased when fresh olive cake was added to the soil, due to the high content of water‐soluble carbon in this amendment. On the contrary, application of the compost and vermicompost decreased the concentration of soluble Zn and did not change the soluble Pb levels in the soil. The DTPA‐Pb and DTPA‐Zn were scarcely affected by the application of the three olive‐derived amendments.     

Trace elements in Bangladesh paddy soils

Abstract

A study was carried out to investigate the status of four micronutrients, iron (Fe), copper (Cu), manganese (Mn), and zinc (Zn), and five other trace elements, cobalt (Co), chromium (Cr), nickel (Ni), lead (Pb), and strontium (Sr), in paddy soils of Bangladesh. Soil samples were digested by hydrofluoric acid (HF)‐nitric acid (HNO₃)‐perchloric acid (HClO₄) for determination of total contents of the nine elements, while DTPA, ASI and 0.1 Mhydrochloric acid (HC1) methods were used for determination of available Fe, Cu, Mn, and Zn. Total trace element contents were found to vary with physiography on which soils are distributed. In general, Ganges Tidal Floodplain soils had the highest content, whereas terrace soils had the lower content. Among the soil properties examined, clay content had a good relation with total trace element contents in the topsoil, except for Sr. Based on the variation with physiography or clay content, the nine trace elements could be grouped into six groups: Cu, Fe and Zn, Pb, Co and Cr and Ni, Mn, Sr. According to the extractable levels of four micronutrients, Bangladesh paddy soils had the medium to optimum amounts of Fe and Cu, but were deficient sporadically in Mn and extensively in Zn. It was indicated that paddy soils of Bangladesh are yet to be polluted with heavy metals.     

Effect of incubation and microbial inhibition at field moisture capacity on changes in DTPA‐extractable Fe,Zn, and Cu in soils of varying pH

Abstract

To determine the effect of incubation on DTPA‐extractable Fe, Zn, and Cu in soils with a wide pH range (4.2 ‐ 9.4) and to determine the nature of this effect, soils were incubated at field moisture capacity for 1 week with and without a sterilant (toluene). After incubation these soils as well as their air‐dry counterparts were analyzed for DTPA‐extractable Fe, Zn, and Cu.

Incubated soils were significantly lower in DTPA‐extractable Fe, Zn, and Cu than air‐dry soils over all soil pH values tested but there was no significant difference in mean values for incubated soils due to the addition of toluene. The results suggest that, upon incubation at field moisture capacity, the decrease in DTPA‐extractable Fe, Zn, and Cu observed was noa‐microbial in nature.     

Immobilization of Zinc Fertilizer in Flooded Soils Monitored by Adapted DTPA Soil Test

Zinc (Zn) deficiency is a persistent problem in flooded rice (Oryza sativa L.). Severe Zn deficiency causes loss of grain yield, and rice grains with low Zn content contribute to human nutritional Zn deficiencies. The objectives of this study were to evaluate the diethylenetriaminepentaacetic acid (DTPA) extraction method for use with reduced soils and to assess differences in plant availability of native and fertilizer Zn from oxidized and reduced soils. The DTPA‐extractable Zn decreased by 60% through time after flooding when the extraction was done on field‐moist soil but remained at original levels when air‐dried prior to extraction. In a pot experiment with one calcareous and one noncalcareous soil, moist‐soil DTPA‐extractable Zn and plant Zn uptake both decreased after flooding compared with the oxidized soil treatment for both soils. In the flooded treatment of the calcareous soil, both plant and soil Zn concentrations were equal to or less than critical deficiency levels even after fertilization with 50 kg Zn ha^?1. We concluded that Zn availability measurements for rice at low redox potentials should be made on reduced soil rather than air‐dry soil and that applied Zn fertilizer may become unavailable to plants after flooding.     

Labile pools of copper and zinc in calcareous soils as measured by DTPA and plant extraction

Abstract

Labile pools of Cu and Zn were measured on two calcareous soils from Saudi Arabia, using successive extraction with DTPA, and successive cropping followed by extraction with DTPA after cropping. The examined soils differed in their ability to supply Cu and Zn. The first DTPA extraction removed a major proportion of the labile pool, particularly in the sandy soil. The two soils showed a general decrease in extractable Cu and Zn with progressive extractions, with DTPA extractable Cu declining more rapidly than Zn. DTPA extractable Cu and Zn determined after cropping were highly correlated with DTPA extractable Cu and Zn values obtained after successive extractions. The results gave evidence on both the contribution of element dissolution from insoluble forms with progressive extraction or cropping, and the usefulness of the DTPA extractant for monitoring the availability of Cu and Zn in these calcareous soils.     

Extractable heavy metals in Atlantic coast soils

Abstract

The analysis of soils, using 0.1 N HC1 as an extractant for the heavy metals, Cd, Cr, Ni and Pb on “fine”; textured North Shore and “coarse”; textured Annapolis Valley soils was completed. Results show ranges of 0.012 to 0.469 parts per million Cd; 0.102 to 2.90 parts per million Cr; 0.16 to 29.25 parts per million Ni and 0.12 to 244.8 parts per million Pb. Correlation studies indicate that the heavy metal content of fine textured soils is less influenced by changes in clay content and organic matter than are coarse textured soils. Generally the surface layers (0–15 cms) are higher in extractable heavy metal content than the lower layers (15–30 cms).     

Organic matter availability for denitrification in soils of different textures and drainage classes

Abstract

Soils from the A, B, and C horizons representing three natural drainage classes and differing textures were chosen to study relationships between denitrification rate and estimates of available carbon. The highest correlation with denitrification rate was obtained with total organic C. Water‐extractable C, mineralizable C and 0.1 N Ba(OH)2‐extractable C produced less satisfactory correlations. When soils of the B and C horizons only were included in the regression analysis, 0.1 N Ba(OH)₂‐extractable C was found to be unsatisfactory as a predictor of available C for soil denitrifiers. None of the four methods for estimating available C were found adequate for B and C horizon soils which were relatively low in available C. Coarser‐textured soils with relatively low C levels had correspondingly low denitrification rates. Regressions of denitrification rate on mineralizable C or water‐extractable C were nonsignificant with poorly drained soils whereas they were highly significant with well or imperfectly drained soils.