Showing papers in "Communications in Soil Science and Plant Analysis in 1977"
TL;DR: In this paper, a new soil test was developed for simultaneous extraction of NO3, P, K, Zn, Fe, Cu and Mn from alkaline soils, which can be stored under mineral oil.
Abstract: A new soil test was developed for simultaneous extraction of NO3, P, K, Zn, Fe, Cu and Mn from alkaline soils. The new extraction solution is 1 M in ammonium bicarbonate (NH4HCO3), 0.005 M in Diethylene Triamine Pentaacetic Acid (DTPA) and has a pH of 7.6. The new extracting solution should be stored under mineral oil. Ten grams of soil are weighed out into 125 ml Erlenmeyer flasks. Two 2.5 ml scoops of Fisher G carbon black (to remove color for colorimetric determination of nitrates) are added to each soil, followed by 20 ml extracting solution. The soil mixture is then shaken on an Eberbach reciprocal shaker for 15 minutes at 180 cycles per minute. The extract is then filtered through a Whatman 42 filter paper or its equivalent for NO3, P, K, Zn, Fe, Cu and Mn determinations. The results obtained with the new procedure are highly correlated with results obtained with Olsen's P test, ammonium acetate K test, and Lindsay and Norvell's DTPA‐Zn, Fe, Cu and Mn test. Regression equations between the ...
761 citations
TL;DR: In this article, a procedure for multi-element analysis of nitricperchloric tissue digests was developed for both plant and animal tissues, and the recommended procedure is rapid, requires a minimum of glassware manipulation and reagent addition.
Abstract: A procedure has been developed for multi‐element analysis of nitric‐perchloric tissue digests. Both plant and animal tissues appear to be quantitatively digested. The recommended procedure is rapid, requires a minimum of glassware manipulation and reagent addition. Analysis of National Bureau of Standards reference material, SRM 1571 (Orchard Leaves) and SRM 1577 (Bovine Liver) was satisfactory for all elements sought.
383 citations
TL;DR: In this article, a method for the analysis of soil extracts and plant tissue ash solutions is described using a direct reading plasma emission spectrometer. But the instrument is programed for 16 elements and is capable of determining the elemental content in prepared solutions at a very rapid rate and at sensitivity levels equal to or better than that obtained using the atomic absorption technique.
Abstract: A method for the analysis of soil extracts and plant tissue ash solutions is described using a direct reading plasma emission spectrometer. The instrument is programed for 16 elements and is capable of determining the elemental content in prepared solutions at a very rapid rate and at sensitivity levels equal to or better than that obtained using the atomic absorption technique.
179 citations
TL;DR: The Diagnosis and Recommendation Integrated System (DRIS) has previously been shown to be a valuable tool in making diagnoses of mineral imbalances in plants which, when corrected, result in yield improvements.
Abstract: The Diagnosis and Recommendation Integrated System (DRIS) has previously been shown to be a valuable tool in making diagnoses of mineral imbalances in plants which, when corrected, result in yield ...
99 citations
TL;DR: The phytotoxicity of five nonessential elements (Co, V, Ti, Ag, Cr) to higher plants was studied in solution culture experiments with bush beans (Phaseolus vulgaris L.V. Improved Tendergreen) as mentioned in this paper.
Abstract: The phytotoxicity of five nonessential elements (Co, V, Ti, Ag, Cr) to higher plants was studied in solution culture experiments with bush beans (Phaseolus vulgaris L. C.V. Improved Tendergreen). All, but in varying degrees, tended to concentrate in roots with a decreasing gradient to stems and leaves. Cobalt was one of the more mobile of the five trace metals. Its toxicity was expressed as severe chlorosis; 43 (with 10‐5 M) and 142 (with 10‐4 M) μg Co/g dry weight in leaves resulted in severe chlorosis. Vanadium as 10‐4 M vanadate resulted in smaller plants but not in chlorosis. Leaf, stem, and root V, respectively, were 13, 8, and 881 μg/g dry weight. Titanium was somewhat mobile with considerable yield decrease at 10‐4 M; leaf, stem, and root Ti concentrations, respectively, were 202, 48, and 2420 μg/g. Symptoms were chlorosis, necrotic spots on leaves, and stunting. Silver was very lethal at 10‐4 M AgNO3; at 10‐5 M yields were greatly decreased, but plants were grown without symptoms. Leaf, s...
86 citations
TL;DR: The results indicate that the DRIS approach is able to make consistent diagnoses of the order of requirement of the above elements by the plant irrespective of position of the leaf on the plant and portion of leaf sampled within certain limits.
Abstract: The indices calculated from the Diagnosis and Recommendation Integrated System (DRIS) are used to interpret previously published data on the variation in N, P, K, Ca and Mg content in corn leaves. The results indicate that the DRIS approach is able to make consistent diagnoses of the order of requirement of the above elements by the plant irrespective of position of the leaf on the plant and portion of leaf sampled within certain limits. The diagnoses are completely consistent if any whole leaf from the middle of the plant is sampled.
51 citations
TL;DR: In this paper, the soybeans were grown in nutrient solutions with 1.0 and 2.0 mg Fe/liter, respectively, and with 0.33 and 5.1 mg Mn/liter.
Abstract: Tolerances to Fe and Mn were determined with Bragg and Forrest (Mn‐intolerant) and T203 and Lee (Mn‐tolerant) soybean (Glycine max. (L.). Bragg was Fe efficient; Forrest and T203 were equally Fe‐inefficient plants. The soybeans were grown in nutrient solutions with 1.0 and 2.0 mg Fe/liter, and with 0.33 and 5.1 mg Mn/liter as variables, respectively. Bragg soybeans developed Fe toxicity symptoms with 2.0, but not with 1.0 mg Fe/liter. Forrest, Lee, and T203 did not develop Fe toxicity symptoms on either treatment. Bragg and Forrest soybean developed more severe Mn‐toxicity symptoms than Lee or T203 soybean when grown on nutrient solutions with 5.1 mg Mn/liter. Approach grafts showed that Mn tolerance appears to be controlled in the plant tops. Both Mn‐intolerant and tolerant soybean tops contained about the same concentration of Mn, but Mn‐tolerant tops contained more K and roots contained less Fe than Mn‐intolerant tops and roots. When Fe and Mn toxicities are not economically correctable, toler...
50 citations
TL;DR: Results indicate that critical total S concentrations in whole plant tops declined markedly with age of regrowth, and it is suggested that plants have adequate sulphur when more than 12% of their total S content is in the sulphate form.
Abstract: The effects of nitrogen fertilization and age of regrowth on a number of indices for assessing the sulphur status of the perennial tropical pasture grass Panicum maximum var. trichoglume (green panic) have been examined in pot experiments. A non‐rectangular hyperbola regression model has been used as an aid in deriving critical sulphur concentrations and evaluating their confidence limits. The merits and limitations of this model together with problems associated with other methods of deriving critical nutrient concentrations are discussed. Results indicate that critical total S concentrations in whole plant tops declined markedly with age of regrowth. Critical sulphate S concentrations were more stable with age of regrowth, concentrations in excess of 0.012% being indicative of adequate sulphur for maximum plant yield. It is also suggested that plants have adequate sulphur when more than 12% of their total S content is in the sulphate form. N:S ratios may provide a useful guide for assessing sul...
49 citations
TL;DR: In this paper, an experiment was conducted in Yolo loam soil with bush beans (Phaseolus vulgaris L.V. Improved Tendergreen) with single and combination treatments of moderately high levels of Cd, Li, Cu, and Ni to test whether or not effects could be additive or synergistic.
Abstract: An experiment was conducted in Yolo loam soil with bush beans (Phaseolus vulgaris L. C.V. Improved Tendergreen) with single and combination treatments of moderately high levels of Cd, Li, Cu, and Ni to test whether or not effects could be additive or synergistic. Copper and Ni together were more toxic than either alone. Copper, Ni, and Cd were more toxic together than any one alone. These effects were probably additive and may be related to a 0.2 pH change caused by Cu which increased uptake of Ni and Mn. Synergistic effects were observed in the Cd and Ni concentrations, especially in the stems of the plants. Because of these interactions, the effects were then tested in solution culture. In solution culture with bush beans Cu and Ni when applied together had synergistic effects on plant concentrations of P, Zn, and Fe (all were decreased) and on the Ni concentration in roots. Also, in solution culture with (2.5 × 10‐5 M) Zn, Cu, and Cd added singly, in pairs, and together, Zn and Cu additively d...
47 citations
TL;DR: The essential trace elements Fe, Mn, Zn, Cu, and B in high concentrations can produce phytotoxicities. as mentioned in this paper found that 5 × 10−4 M and 10−3 M FeSO4, but not from equivalent amounts of FeEDDHA (ferric ethylenediamine di (o'hydroxyphenylacetic acid) ).
Abstract: The essential trace elements Fe, Mn, Zn, Cu, and B in high concentrations can produce phytotoxicities. Iron toxicity resulted from 5 × 10‐4 M and 10‐3 M FeSO4, but not from equivalent amounts of FeEDDHA (ferric ethylenediamine di (o‐hydroxyphenylacetic acid) ). Leaf concentrations in bush beans of 465 μg Mn/g, 291 μg B/g, and 321 μg Zn/g all on the dry weight basis resulted in 27%, 45%, and 34% reduction in yields of leaves, respectively. Zinc was concentrated in roots while Mn and B concentrated in leaves. Solution concentrations of MnS04 of 10‐3 and 10‐2 M depressed leaf yields of bush beans by 63% and 83%, respectively, with 5140 and 10780 μg Mn/g dry weight of leaves. Copper concentrations were simultaneously increased and those of Ca were decreased. Bush bean plants grown in Yolo loam soil with 200 μg Cu/g soil had a depression in leaf yield of 26% (with 28. 8 μg Cu/g leaf); plants failed to grow with 500 μg Cu/g soil. A level of 10‐3 M H2MoO4 was toxic to bush beans grown in solution cultur...
45 citations
TL;DR: Foliar diagnostic norms for NPK in wheat leaves derived using Beaufils’ Diagnosis and Recommendation Integrated System (DRIS) are presented and are able to correctly diagnose the requirements of the crop more often than those based on the critical or sufficiency level approach.
Abstract: Foliar diagnostic norms for NPK in wheat leaves derived using Beaufils’ Diagnosis and Recommendation Integrated System (DRIS) are presented. These norms were calculated from published and unpublished data of various workers who presented leaf composition with corresponding yields. The preliminary norms appear to be applicable to wheat irrespective of variety and age at which the leaf sample is taken. These norms are able to correctly diagnose the requirements of the crop more often than those based on the critical or sufficiency level approach.
TL;DR: In this article, the authors determined the level of Ba in plants necessary to cause yield depressions and showed that Ba levels of about 2% in bush bean leaves and 1% in barley leaves decreased yields considerably.
Abstract: The purpose of this study was to determine the level of Ba in plants necessary to cause yield depressions. Barium levels of about 2% in bush bean leaves and 1% in barley leaves decreased yields considerably. The levels were obtained after application of 2000 μg Ba per g of soil as Ba(NO3)2 with equivalent nitrate added in controls.
TL;DR: In this paper, the main objective of the study was to ascertain effects of some edaphic factors on the uptake and influence of Ni on plant growth sinee Ni is a common trace element contaminant as well as an important component of serpentine soils.
Abstract: The main objective of this study was to ascertain effects of some edaphic factors on the uptake and influence of Ni on plant growth sinee Ni is a common trace element contaminant as well as an important component of serpentine soils. Corn (Zea mays L. inbred Ys1/Ys1) was rown in Yolo loam soil amended to give soil pH values of 4.2, 5.6, 7.5, and 8.2. A level of 100 μg Ni/g soil was not toxic to the corn. Shoot concentrations of Ni increased as soil pH decreased for both application rates of Ni. A level of 250 μg Ni/g soil decreased yields more at soil pH below 7 than above 7. Iron, Zn, and Mn levels in shoots did not appear to be directly related to the Ni applications although Fe levels tended to increase as a result of smaller plant size. PI54619–5–1 soybeans (Glycine max L. ) were grown in soil at two different pH values (with and without CaCO3) and with and without a level of 1000 μg Ni/g added as the sulfate and thoroughly mixed with the soil and equilibrated for 1 month prior to transplanti...
TL;DR: In this article, the toxicity of Li to three plant species was studied to determine if there were interactions with other elements and to determine whether a chelating agent modified Li toxicity, and they found that higher levels of Li decreased Zn in leaves, increased Ca in stems, and generally increased Fe and Mn in all plant tissues.
Abstract: The toxicity of Li to three plant species was studied to determine if there were interactions with other elements and to determine if a chelating agent modified Li toxicity. Bush beans (Phaseolus vulgarls L. C.V. Improved Tendergreen), grown in solution culture, were sensitive to 0.5 X10‐3Li which resulted in 10 μg/g in leaves, 48 in stems, and 24 in roots. Higher concentrations of Li produced marked reductions in plant yield accompanied by increased Li concentrations in leaf, stem, and root tissues. For most treatments, root concentrations of Li were lower than those in shoots, but those in stems were higher than those in leaves. Higher levels of Li decreased Zn in leaves, increased Ca in stems, and generally increased Fe and Mn in all plant tissues. Ethylenediamine tetraacetic acid (EDTA) resulted in slightly increased Ii levels in leaves, stems, and roots. Bush bean plants were injured slightly with 25 μg Li/g of Yolo loam soil applied as LiCl; 50 μg Li/g soil caused more severe injury. Leaf c...
TL;DR: In this paper, the authors compared single buffer-two pH and two buffer adaptations as double buffer features of the SMP method using a group of 54 soils of wide range in lime requirement (LR).
Abstract: Single buffer‐two pH and two‐buffer adaptations were compared as double buffer features of the SMP method using a group of 54 soils of wide range in lime requirement (LR). Data from both methods were highly correlated both with each other and with Ca(OH)2‐titrated acidity. Formulas for LR based on the schematics of similar triangles relating differences in measured pH vs corresponding acidities for the double buffer system were developed. A regression equation relating buffer‐indicated LR and Ca(OH)2 titrated acidity was used to adjust the quick‐test double buffer‐indicated values to levels nearer the actual ones. A recommended SMP double buffer procedure, and a formula for computing LR from soil‐buffer pH's measured by the double buffer, quick‐test method are presented.
TL;DR: In this paper, the major purpose of these experiments was to determine if Pb uptake by plants was significantly increased by chelating agents used in plant nutrition, and the experiments were conducted in a glasshouse with different rates of Pb in solution culture and in amended soil.
Abstract: The major purpose of these experiments was to determine if Pb uptake by plants was significantly increased by chelating agents used in plant nutrition. The interaction of Pb with some other elements in barley plants (Hordeum vulgare L. C.V. Atlas 57) and bush bean (Phaseolus vulgaris L. C.V. Improved Tendergreen) was studied in a glasshouse with different rates of Pb in solution culture and in amended (control, S, CaCO3, MgCO3) Yolo loam soil with and without the chelating agent DTPA (diethylene triamine pentaacetic acid). In a solution culture experiment, 10‐3 M Pb significantly decreased bush bean yields in both control and DTPA treatments. The CaCO3 added to nutrient solution decreased the concentration of Pb in leaves, stems, and roots and prevented the toxicity of 10‐3 M Pb++. At high Pb levels, interactions between Pb and Mn and Pb and Fe were observed, except with CaCO3. In the soil experiment, the yields of barley and bush bean were influenced only slightly by Pb. The Pb concentration in ...
TL;DR: Soil samples were taken at frequent intervals in 1975 and 1976 from a factorial set of lime treatments initiated in December 1970 to determine the effect time of sampling has on K soil test values as discussed by the authors.
Abstract: Soil samples were taken at frequent intervals in 1975 and 1976 from a factorial set of lime ‐K treatments initiated in December 1970 to determine the effect time of sampling has on K soil test values Previous work at this site had shown wide fluctuations in K soil test values due to sample time thus necessitating a more detailed study than was previously made Such information is necessary if accurate K fertilizer recommendations are to be made Samples from 28 unfertilized plots showed that months of sampling significantly affected K soil test values Soil test values for K were highest in late May and declined as the growing season progressed, remaining low until the relatively higher exchangeable K was re‐established the following spring Disregard for this phenomenon could result in inaccurate recommendations for K fertilizer
TL;DR: In this article, the effects of sample preparation and storage on levels of water-soluble Mn in 5 Mississippi soils were determined, and the most pronounced effect was found in steam sterilization followed by methyl bromide and various degrees of air-drying.
Abstract: The effects of sample preparation and storage on levels of water‐soluble Mn in 5 Mississippi soils were determined. Steam sterilization has the most pronounced effect followed by methyl bromide and various degrees of air‐drying. In general, storage of soils in the moist or frozen condition will result in minimum changes in water‐soluble Mn. However, expected changes are not predictable and each soil will have to be investigated separately if it is necessary to know the effect of a particular treatment on available Mn.
TL;DR: In this article, the effects of the chemical and physical properties of surface and subsurface soils of a temperate region on P sorption from solutions containing various concentrations of P were evaluated.
Abstract: Several factors affect phosphate sorption by soils. This study was conducted to evaluate the effects of the chemical and physical properties of surface and subsurface soils of a temperate region on P sorption from solutions containing various concentrations of P. Results showed that Na2S2O4‐extractable Fe and Al of surface soils were significantly correlated with P sorption from a solution containing 10, 15, or 20 ppm P. The relationships between the amounts of P sorbed and the other properties of the surface and subsurface soils studied (e.g., pH, organic C, soluble P, CEC) were influenced by use of 0.01M CaCl2 as an equilibrating solution. The values of P adsorption maxima calculated from soil‐water systems were from 1.2‐ to 2.1‐fold higher than those calculated from soil‐0.01M CaCl2 systems. But the Langmuir adsorption constants calculated from results obtained in the presence of CaCl2 were from 7‐ to 27‐fold higher than those in the absence of salt.
TL;DR: Earlirose rice (Oryza sativa L. ) and Hawkeye soybeans (Glycine max L.) were grown in solution culture with A12(SO4)3 in concentrations of 0, 10 6, 10 5, 10 4, 10 3 M were there yield depressions due to Al as discussed by the authors.
Abstract: Earlirose rice (Oryza sativa L. ) and Hawkeye soybeans (Glycine max L.) were grown in solution culture with A12(SO4)3 in concentrations of 0, 10‐6, 10‐5, 10‐4, 10‐3 M. Only at 10‐4 (slightly) and at 10‐3 M were there yield depressions due to Al. The threshold concentration of Al for toxicity was about 20 μg/g in rice shoots and about 30 μg/g in soybean leaves. The solution level necessary for these concentrations was 8 μg Al/ml. Plant concentrations which caused severe toxicity were 70 μg Al/g plant with 81 μg Al/ml solution. Most Al remained in roots, but leaves contained more than did stems of soybeans. The high Al decreased Fe, Cu, and Mn concentrations in shoots of rice and decreased Fe, Cu, and Zn in roots of rice. The high Al resulted in decreased Fe and Zn in leaves of soybeans. No Fe deficiency symptoms were present due to the high Al.
TL;DR: In this paper, Cadmium in solution culture at 10−4 M decreased Mn concentrations in bush beans (Phaseolus vulgaris L.V. Improved Tendergreen) at both low and high concentrations of Mn (noncompetitive inhibition).
Abstract: Cadmium in solution culture at 10‐4 M decreased Mn concentrations in bush beans (Phaseolus vulgaris L. C.V. Improved Tendergreen) at both low and high concentrations of Mn (noncompetitive inhibition). When Mn was decreased, the concentrations of Fe and several other ions were simultaneously increased, particularly in leaves and roots. Toxicity due to the 10‐6 M Cd and the 10‐4 M Mn was additive in the experiment. When barley (Hordeum vulgare L. Atlas57)was grown in amended soil, 15μg Fe as DTPA (diethylene triamine pentaacetic acid) per g soil resulted in increased uptake of Cd and in somewhat greater yield depression for soil pH of 3.9, 6. 0, and 7.6. Acidification of soil without DTPA also increased Cd uptake to high levels with associated yield decrease. The Cd decreased the uptake of Mn and Cu most when CaCO3 had also been added to the soil. When salts were added to soil with Cd before bush beans were grown, KCl (200 μg K/g soil), and equivalent KH2PO4 increased Cd concentrations of leaves wh...
TL;DR: In this paper, the effect of three boron rates applied to the soil on the distribution and relative abundance of 12 chemical elements in various alfalfa plant parts at four successive stages of growth was determined.
Abstract: The objectives of this study were to determine the effect of three boron rates applied to the soil on the distribution and relative abundance of 12 chemical elements in various alfalfa plant parts at four successive stages of growth. Plant samples were separated into lower leaves, lower stems, upper leaves, upper stems, and tips. These plant parts were analyzed for Zn, B, Fe, Mn, Mg, Ca, P, K, Na, Al, Si, and Cu. Results of this study indicated: application of B to the soil resulted in increases in concentration of B in alfalfa tissue proportional to the rate of B applied. For most elements, a decrease in concentration was generally obtained when the rate of soil‐applied boron was increased from 6.3 to 12.6 kg/ha; a continual increase in the B concentration from early vegetative to bloom stage of growth and then, a decrease in the B concentration from bloom to seed set was observed for the entire alfalfa plant; the concentration of an element found in leaf tissue was generally greater than the co...
TL;DR: While total N: total S ratios varied widely from 4 to 331 depending on plant part, age, N supply and S supply, there was no discernable trend in protein N: protein S ratios attributable to any of these factors.
Abstract: While total N: total S ratios varied widely from 4 to 331 depending on plant part, age, N supply and S supply, there was no discernable trend in protein N: protein S ratios attributable to any of these factors. The results also show that it is difficult to extract all of the non‐protein N and non‐protein S from plant tissue. This could explain the variation in protein N: protein S ratios found by some workers.
TL;DR: Most fertilizer and lime recommendations are based on: i) a level of available nutrient (or pH) sufficient for at least near-maximum crop yields and ii) an average rate of buildup of the available nutrient or pH per unit of fertilizer (or lime) added.
Abstract: Most fertilizer (and lime) recommendations are based on: i) a level of available nutrient (or pH) sufficient for at least near‐maximum crop yields and ii) an average rate of buildup of the available nutrient (or pH) per unit of fertilizer (or lime) added. Soils differ widely in the rate of buildup of available nutrient per unit of added fertilizer. Soil type (or association) is generally not available for individual soil samples submitted for testing. Even if it were, research information is generally inadequate to adjust the recommendations with any great degree of accuracy on this basis alone. Thus it seems imperative that new tests and/or equilibrations for individual soil samples be developed to provide the information needed. Recent results by us and others seems to offer hope of success in such efforts. Lime and fertilizer costs are a substantial portion of the total production costs in modern farming. Thus, it is important that the rates recommended be the best possible for the individual ...
TL;DR: Aluminum in soil saturation extracts and exchangeable Al determined by N KCl extraction were studied using a large number of Ultisol and Alfisol samples from West Africa in this paper, where the concentration of soil solution Al ranged from 0.05 to 4.5 ppm.
Abstract: Aluminum in soil saturation extracts and exchangeable Al determined by N KCl extraction were studied using a large number of Ultisol and Alfisol samples from West Africa. The concentration of soil solution Al ranged from 0.05 to 4.5 ppm. Solution Al content was generally higher in the surface horizon (Ap and A1) than in the lower horizons within the same profile; whereas the reverse was true for exchangeable Al. For subsoil samples, the percentage exchangeable Al saturation was highly correlated with soil pH measured both in water and in N KCl. But for surface soil samples, the correlations were poor.
TL;DR: In this paper, the authors showed that a high level of Fe improved growth of plants in the presence of 25 × 10−5 M Ni, but not with 5 × 10•5 MNi.
Abstract: Bush beans (Phaseolus vulgaris L C V Improved Tendergreen) plants were grown in solution culture and in soil with different levels of Fe and Ni to determine more precisely if Fe would overcome part of the phytotoxicity caused by Ni In solution culture, a high level of Fe improved growth of plants in the presence of 25 × 10‐5 M Ni, but not with 5 × 10‐5 MNi The 25 × 10‐5 M Ni decreased Fe concentrations in leaves, but not in other plant parts The 5 × 10‐5 M Ni also decreased Fe concentrations in leaves relative to the controls although they were increased relative to those for 25 × 10‐5 MNi The high Fe levels did not decrease Ni concentrations in plant parts In soil Fe chelate improved plant growth at 50 and 100 μg Ni/g soil, but not at higher levels of Ni The Fe did not depress Ni concentrations in leaves and Ni had no effect on Fe concentrations
TL;DR: In this article, a greenhouse experiment with 24 and 31 days following emergence from pots containing Bloomfield loamy sand (Psammentic Haplaudalf) was conducted and the results indicated that Cd and Pb significantly affected the B concentration of corn plants 24 days following the emergence, and specific main effects (linear and/or quadratic) influenced the concentration of other nutrients.
Abstract: In a greenhouse experiment corn plants were harvested 24 and 31 days following emergence from pots containing Bloomfield loamy sand (Psammentic Haplaudalf). Soil P was 140 kg/ha, exchangeable K was 220 kg/ha, and soil pH was 6.0. The soil CEC was 2.3 meq/100 g. Boron, Cu, Mn, and Zn were determined with emission spectroscopy. Treatment combinations were a factorial arrangement of 0, 2.5, and 5 μg/g of Cd and 0, 125, and 250 μg/g of Pb. Main effects of Cd and Pb significantly affected the B concentration of corn plants 24 days following emergence, and specific main effects (linear and/or quadratic) influenced the concentration of other nutrients. At the later stage of development (31 days following emergence), neither Cd nor Pb affected B concentration in corn plants, and there was only one significant (α = 0.05) main effect influencing the nutrient status of other micro‐nutrients studied. However, several Cd‐Pb interactions affected micronutrient concentration in corn plants. Our results suggest ...
TL;DR: In this paper, a method for reproducibly separating from soils minimally altered, clay-size soil organic-mineral particles (SO-MPs) by water dispersion and density centrifugation was devised.
Abstract: A method has been devised for reproducibly separating from soils minimally altered, clay‐size soil organic‐mineral particles (SO‐MPs) by water dispersion and density centrifugation. Active surfaces of SO‐MPs so obtained should represent more closely those actually interfacing with root systems and microbes than the chemically cleaned clay or humic materials conventionally obtained in laboratory prepartions. The method reduces heterogeneity within given size fractions of SO‐MPs, which is desirable for studying relationships between composition and properties of minimally altered soil “fines”.
TL;DR: In this paper, the authors extracted calcium from leaves sequentially with water, 0.5M sodium nitrate, 2M acetic acid and 2M hydrochloric acid.
Abstract: Calcium was extracted from leaves sequentially with water, 0.5M sodium nitrate, 2M acetic acid and 2M hydrochloric acid. Water and hydrochloric acid removed well defined fractions; water soluble calcium was mostly present in complexed form; hydrochloric acid removed only calcium oxalate. The results show that some oxalic acid may be produced by acid hydrolysis of plant constitutents during extraction with hydrochloric acid. Drying of leaves prior to analysis altered the distribution of calcium; water soluble calcium decreased while acetic and hydrochloric acid soluble calcium increased.