Effects of Nickel on Growth and Composition of Metal Micronutrients in Barley Plants Grown in Nutrient Solution

Abstract

A hydroponic experiment was conducted in a phytotron at pH 5.5 to study the effects of nickel (Ni) on the growth and composition of metal micronutrients, such as copper (Cu), iron (Fe), manganese (Mn), and zinc (Zn), of barley (Hordeum vulgare L. cv. Minorimugi). Four Ni treatments were conducted (0, 1.0, 10, and 100 μM) for 14 d. Plants grown in 100 μM Ni showed typical visual symptoms of Ni toxicity such as chlorosis, necrosis of leaves, and browning of the root system, while other plants were free from any symptoms. Dry weights were the highest in plants grown in 1.0 μM Ni, with a corresponding increase in the chlorophyll index of the plants, suggesting that 1.0～10 μM Ni needs to be added to the nutrient solution for optimum growth of barley plants. The increase of Ni in the nutrient solutions increased the concentrations of Cu and Fe in roots, while a decrease was observed in shoots. The concentrations of Mn and Zn in shoots and roots of plants decreased with increasing Ni supply in the nutrient solution. Shoot concentrations of Cu, Fe, Mn, and Zn in plants grown at 100 μ M Ni were below the critical levels for deficiency. Plants grown at 1.0 μ M Ni accumulated higher amounts of Cu, Fe, Mn and Zn, indicating that nutrient accumulation in plants was more influenced by dry weights than by nutrient concentrations. The translocation of Cu and Fe from roots to shoots was repressed, while that of Mn and Zn was not repressed with increasing Ni concentration in the nutrient solution.     

NUTRIENT AND GROWTH RESPONSES OF LEERSIA ORYZOIDES,RICE CUTGRASS,TO VARYING DEGREES OF SOIL SATURATION AND WATER NITROGEN CONCENTRATION

Leersia oryzoides (rice cutgrass) is an obligate wetland plant common to agricultural drainage ditches. The objective of this greenhouse study was to expose plants to various flooding and aqueous nitrogen (N) concentrations and then to quantify the allocation of nutrients and biomass to plant components. Plants in the continuously flooded treatment (CF) had the highest tissue concentrations of copper (Cu), sulfur (S), zinc (Zn), potassium (K), sodium (Na), and manganese (Mn) in one or more plant components. Plants in the partially flooded treatment (PF) had the highest concentrations of magnesium (Mg) in leaves. The N input affected phosphorus (P) and S concentrations in roots. Leaf, stem, and root biomass were highest in PF plants. Rhizome biomass was the lowest in CF plants. These results indicate that L. oryzoides may significantly affect elemental concentrations in surface waters by its ability to uptake various elements and subsequent sequestration in various biomass components.     

Metal concentrations,growth, and yield of potato produced from In Vitro plantlets or microtubers and grown in municipal solid‐waste‐amended substrates

In vitro plantlets or microtubers (in vitro produced tubers) of ‘Spunta’ potato (Solanum tuberosum L.) were planted in a 3 soil: 2 peat moss: 1 sand substrate (by volume) amended with municipal solid waste (MS W) compost at 0, 10, 20, or 30 g 4^‐1 L pot. Three months later, plant growth and tuber yield were evaluated and concentrations of shoot and tuber tin (Sn), arsenic (As), copper (Cu), zinc (Zn), nickel (Ni), lead (Pb), manganese (Mn), cadmium (Cd), and iron (Fe) were determined. Amending with MSW resulted in significant increases in concentrations of all tested metals in the substrate. Number of proliferated shoots of plants started from rooted plantlets was greatest at 10 g pot^‐1 MSW, whereas shoot weight of plants started from microtubers was greatest at 10 and 20 g pot^‐1 MSW. Tuber yield of plants started from rooted plantlets or microtubers was greatest at 10 or 30 g pot^‐1 MSW, respectively. In all instances, amending with MSW at 30 g pot^‐1 resulted in significant increases in concentrations of all tested metals in shoots and tubers. Concentrations of shoot Ni and tuber Zn and Fe for plants started from rooted plantlets and concentrations of shoot Fe and tuber As, Cu and Pb for plants started from microtubers increased consistently with increasing MSW percentage of the substrate. Plants started from rooted plantlets produced shoots with sufficient Zn, Mn, and Ni concentrations regardless of the substrate but with toxic Cu content at 30 g pot^‐1 MSW. Plants started from microtubers produced shoots with sufficient Mn and Ni concentrations regardless of the substrate but with low Zn and deficient Cu in unamended substrates. All plants had shoot Fe content higher than the sufficiency range. Although there were significant differences in concentrations of some nutrients among MSW treatments, no symptoms of nutrient toxicity or deficiency were observed. In all instances, tested elements did not accumulate in tubers to levels hazardous to human health. Concentrations of Cd, the most hazardous element, in potato tubers was not high enough to pose a threat to human. Our results indicate that there is a potential use of MSW in satisfying the needs of potato growth with negligible increases in heavy metal concentrations in tubers.     

Phytotoxic effects of industrial and sewage waste waters on growth,chlorophyll content,transpiration rate and relative water content of potted sunflower plants

Waste water coming from two factories, namely Manquabad (fertilizer) and Bani Qura (detergents and oils) factory and Arab El-Madabegh sewage effluents were determined for their phytotoxicities and physicochemical properties. The effect of the waters on the growth, chlorophyll content, transpiration rate and leaf relative water content of sunflower plants was undertaken in pots. In addition, the phytotoxicity present in the waste waters on embryonic radicle growth was also studied. The experiments were repeated each month from January to June, 1992. The three waste waters exhibited significant phytotoxic effects on the radicle growth of sunflower. The phytotoxicity varied with monthly sampling. The waste water from the fertilizer factory (Manquabad) collected in February, May and June showed almost 100% inhibition on the radicle growth, while January and April sampling had a stimulatory effect. Most of the tested water exhibited significant inhibition on shoot growth. Root growth was significantly enhanced by Arab El-Madabegh sewage water collected in February, March and April and was suppressed in the other three months. The three waste waters showed inhibitory effect on chlorophyll content. The inhibition was very high in the January sampling. Chlorophyll stability to heat was significantly lower in February and March and higher in May and June water-treated plants. Generally waste water-treated plants showed a lower transpiration rate than the control (tap water). Leaf relative water content of plants grown in the waste waters was significantly lower in May and June collected water than in the other four months collections. The physicochemical analysis of the waste waters revealed that the amount of Na⁺, K⁺, Ca⁺² Zn⁺², Cu⁺², Iron, Cl^?, SO₄ ^?2 and the degree of electrical conductivity were often above the limits of the standard for irrigation water for agricultural land, and some of these properties would be severely detrimental to crop growth. Generally waste water coming from the Manquabad fertilizer factory consistently revealed the highest inhibition, Bani Qura detergents and oils factory the second and Arab El-Madabegh sewage the least.     

镉处理根表铁膜对水稻吸收镉锰铜锌的影响

本试验利用营养液和土壤培养系统,研究不同Fe、 Cd处理下根表铁膜对水稻吸收Cd、 Mn、 Cu、 Zn的影响。土壤中Fe的水平为0、 1、 2 g/kg Fe（以FeSO47H2O的形式供应）,Cd 的水平为0、 2、 10 mg/kg Cd（以3CdSO48H2O的形式供应）。营养液中Fe和Cd的水平分别为0、 10、 30、 50、 80、 100 mg/L Fe 和 0、 0.1、 1.0 mg/L Cd。收获后测定水稻根表、 根中和地上部Cd、 Fe、 Mn、 Cu、 Zn 含量。试验结果表明,两种培养方式下,随着介质中Fe浓度的增加,水稻根表铁膜（DCB-Fe）逐渐增多。土壤培养方式下,根表铁膜中Cd 和 Mn 含量随铁膜量增加而略有增加,所有元素含量均表现为根中大于铁膜中。营养液培养条件下,根表铁膜中Mn和Cu含量在高量 Fe 供应时有所增加, Mn、 Cu、 Zn表现为铁膜中大于根中。根表铁膜中Zn含量在两种培养方式下均未呈现一定规律性变化。根中和地上部 Cd、 Mn、 Cu、 Zn 含量一般都随介质中Fe浓度的增加而下降,Cu和Zn含量在加Cd处理中下降。以上结果证明,铁膜对Cd 的吸附阻挡能力有限,对Mn、 Cu、 Zn 的吸附作用因培养方式和元素种类不同而有所差异,植株体内微量元素含量的下降主要与它们之间的相互抑制作用有关。     

Evaluation of the Suitability of Sewage and Recycled Water for Irrigation of Ornamental Plants

The present study was conducted to evaluate the potential benefits and risks of the sewage water and recycled treated water on three ornamental plant species, including Umbrella plant (Cyperus alternifolius), Euonymus (Euonymus japonicas), and Dracaena (Cordyline terminalis). Plants in the pots were irrigated with equal volumes of water in 2-day intervals. Treatment plants were analyzed for sodium (Na), potassium (K), copper (Cu), iron (Fe), and lead (Pb) concentrations, in roots and shoots. The experiment was conducted by using a completely randomized design (CRD) with five replications. Data were analyzed using analysis of variance technique and least significance difference (LSD) test was applied at 5% probability level. Plants species performed better in sewage water after recycled water, in terms of growth, number of leaves, chlorophyll content, and leaf thickness, which proved sewage water accelerates the growth and development of ornamental foliage plants, but plants irrigated with this water exhibited greater concentration of Pb than other treatments.     

Effects of excess manganese on mineral uptake in mycorrhizal sorghum

Associations between vesicular‐arbuscular mycorrhizal (VAM) fungi and manganese (Mn) nutrition/toxicity are not clear. This study was conducted to determine the effects of excess levels of Mn on mineral nutrient uptake in shoots and roots of mycorrhizal (+VAM) and non‐mycorrhizal (‐VAM) sorghum [Sorghum bicolor (L) Moench, cv. NB9040]. Plants colonized with and without two VAM isolates [Glomus intraradices UT143–2 (UT1 43) and Gl. etunicatum UT316A‐2 (UT316)] were grown in sand irrigated with nutrient solution at pH 4.8 containing 0, 270, 540, and 1080 μM of added Mn (as manganese chloride) above the basal solution (18 μM). Shoot and root dry matter followed the sequence of UT316 > UT143 > ‐VAM, and shoots had greater differences than roots. Shoot and root concentrations and contents of Mn, phosphorus (P), sulfur (S), potassium (K), calcium (Ca), magnesium (Mg), iron (Fe), zinc (Zn), and copper (Cu were determined. The +VAM plants generally had higher mineral nutrient concentrations and contents than ‐VAM plants, although ‐VAM plants had higher concentrations and contents of some minerals than +VAM plants at some Mn levels. Plants colonized with UT143 had higher concentrations of shoot P, Ca, Zn, and Cu and higher root Mg, Zn, and Cu than UT316 colonized plants, while UT316 colonized plants had higher shoot and root K concentrations than UT143 colonized plants. These results showed that VAM isolates differ in enhancement of mineral nutrient uptake by sorghum.     

The dynamic state of the ionome in roots,nodules, and shoots of soybean under different nitrogen status and at different growth stages

The relative distribution of 22 mineral elements in the roots, nodules and shoots of the soybean (Glycine max L. Merr. cv. Tsurumusume) at R1 (beginning of the flowering stage) and R7 (beginning of the mature stage) was investigated in response to ammonium and manure N treatment. Plants receiving only atmospheric nitrogen served as the negative control. The addition of ammonium sulfate to the soil caused soil acidification, induced Al and Mn toxicities, and significantly reduced the biomass production in roots and nodules. Ca, Mg, Fe, Mn, Cu, and Zn concentrations were significantly higher in shoots, and those of Mo and Co higher in nodules. The addition of manure to the soil significantly enhanced the levels of Sr, Ba, Cr, and Cd in shoots, whereas the concentration of Cs was decreased at R7. Moreover, when the soybean developed from R1 to R7, the levels of essential elements in nodules decreased, whereas those of nonessential elements increased, irrespective of the nitrogen source. Furthermore, the variation in the concentrations of many elements was not consistent for nodules and roots when soybean developed from R1 to R7. The variation of Mn, Zn, B, and Al concentrations was independent of N treatments. However, Ca, Fe, Cu, Mo, and Se levels were affected strongly by N treatments. This study is the first to document the dynamic variation of the soybean ionome in nodules, roots, and shoots from vegetative to reproductive stage of soybean.     

Foliar-applied glyphosate substantially reduced uptake and transport of iron and manganese in sunflower (Helianthus annuus L.) plants

Evidence clearly shows that cationic micronutrients in spray solutions reduce the herbicidal effectiveness of glyphosate for weed control due to the formation of metal-glyphosate complexes. The formation of these glyphosate-metal complexes in plant tissue may also impair micronutrient nutrition of nontarget plants when exposed to glyphosate drift or glyphosate residues in soil. In the present study, the effects of simulated glyphosate drift on plant growth and uptake, translocation, and accumulation (tissue concentration) of iron (Fe), manganese (Mn), zinc (Zn), and copper (Cu) were investigated in sunflower (Helianthus annuus L.) plants grown in nutrient solution under controlled environmental conditions. Glyphosate was sprayed on plant shoots at different rates between 1.25 and 6.0% of the recommended dosage (i.e., 0.39 and 1.89 mM glyphosate isopropylamine salt). Glyphosate applications significantly decreased root and shoot dry matter production and chlorophyll concentrations of young leaves and shoot tips. The basal parts of the youngest leaves and shoot tips were severely chlorotic. These effects became apparent within 48 h after the glyphosate spray. Glyphosate also caused substantial decreases in leaf concentration of Fe and Mn while the concentration of Zn and Cu was less affected. In short-term uptake experiments with radiolabeled Fe (59Fe), Mn (54Mn), and Zn (65Zn), root uptake of 59Fe and 54Mn was significantly reduced in 12 and 24 h after application of 6% of the recommended dosage of glyphosate, respectively. Glyphosate resulted in almost complete inhibition of root-to-shoot translocation of 59Fe within 12 h and 54Mn within 24 h after application. These results suggest that glyphosate residues or drift may result in severe impairments in Fe and Mn nutrition of nontarget plants, possibly due to the formation of poorly soluble glyphosate-metal complexes in plant tissues and/or rhizosphere interactions.     

Multielement analysis of natural waters by neutron activation,group chemical separations,and gamma-ray spectrometric techniques

A multielement analytical technique of thermal neutron activation of frozen water samples has been developed and applied to the studies of natural waters. A rapid group chemical separation utilizing ion exchange resins and a precipitation step to reduce ²⁴Na and 42K interferences, followed by γ-ray analysis of the fractions with Ge (Li) and multiparameter NaI (TI) systems, permits the simultaneous measurement of a large number of trace constituents. Samples of river water, rain water, processed sewage water and Greenland ice were analyzed for 19 trace elements — Ag, As, Br, Cl, Co, Cs, Cr, Cu, Fe, Hg, K, Mn, Na, Rb, Sb, Se, Se, U, and Zn. These data have been used in studies of trace element concentration factors in aquatic biota, precipitation scavenging processes, and environmental pollution.     

Effects of Foliar Spray of K on Mint,Radish, Parsley and Coriander Plants in Aquaponic System

An aquaponic system was designed to investigate the effects of foliar applications of potassium (K) on mint, radish, parsley, and coriander growth and physiological characteristics. Plants were sprayed with 100 mL pot^?1 of 0.5 g L^?1 potassium sulfate (K₂SO₄) twice a week. Fresh and dry masses of shoot in all species were higher in K-treated plants. Potassium concentration increased with K spray in the shoots of all species. K-sprayed parsley accumulated a greater amount of Fe and chlorophyll in shoots. Values of SPAD index in all species decreased significantly in untreated plants. The highest Quantum Photosynthetic Yield (F_v/F_m) values were observed in coriander plants treated with K, which was attributed to higher SPAD value in these plants. Potassium application had a negative effect on sodium (Na) and positive effect on magnesium (Mg), manganese (Mn), and zinc (Zn) concentrations in plants. These results indicated that foliar spray of K can effectively alleviate nutrient deficiencies in leafy and root vegetables grown in aquaponics.     

Gehalte von Baumwurzeln an chemischen Elementen einschließlich Schwermetallen aus Luftverunreinigungen

Concentrations of chemical elements in tree roots including heavy metals from air pollution Total concentrations of P, S, Na, K, Mg, Ca, Al, Cr, Mn, Fe, Co, Ni, Cu, Zn, Cd and Pb were measured in roots from beech, spruce, ash, maple and a forest herb (Mercurialis perennis). The root samples were taken from a site with an acid soil type (Saure Braunerde) and from a site with calcareous soil (Rendzina). All elements except Mn, Zn and Pb (on acid soils) and Ca (on calcareous soils) showed higher concentrations in finest roots (<1 mm diameter) compared to fine roots (1–2 mm). In the case of the toxic heavy metals, this is interpreted as a consequence of reduced root uptake due to physiological processes or to organic complexing, followed by an accumulation at the root surface. Compared with aboveground plant parts, roots show accumulation of Al, Pb, Cd and Zn, indicating reduced translocation from roots to shoots. Roots from acid soil show higher concentrations of P, Mn, and Pb than in calcareous soil. The concentrations of Al and heavy metals in the roots are considered to be a consequence of the contamination of the investigated forest sites by long-range transported air pollutants, i.e. acid precipitation and deposition of heavy metals.     

Effects of Long‐Term Irrigation using Industrial Wastewater on Soil Properties and Elemental Contents of Rice,Spinach, Clover,and Grass

Abstract

Application of industrial wastewater on agricultural lands increased the amounts of elements in soil and plants. To investigate the effects of wastewater on soil properties and element content in soil and plants, wastewaters of three industries (chrome chemical, wood and paper, and textiles) were examined in 2005. At harvest time, the soil samples were taken from depths of 0–15 and 15–30 cm, and the roots and shoots of rice, spinach, clover, and grass and grain of rice in an industrial wastewater–treated area and untreated area were sampled. Results indicated that the concentrations of zinc (Zn), copper (Cu), manganese (Mn), and iron (Fe) increased in river water when wastewater was discharged into it. Use of the river water, influenced by industrial wastewater, for irrigation of rice and other plants increased the amounts of organic matter and available Zn, Cu, Mn, and Fe in soil. Cation exchange capacity was correlated with available Cu and Fe in soil (+0.431** and +0.499**, respectively). Soil organic matter was correlated with available Zn, Cu, Mn, and Fe in soil. However, the clay content in soil did not correlate with these elements. Meanwhile, in roots, shoots, and grains of rice and roots and shoots of spinach, clover, and grasses of agricultural land influenced by industrial wastewater, the amounts of Zn, Cu, Mn, and Fe increased. Therefore, by increasing the amount of Mn in the soil, the concentration of Zn in rice grain decreased and the concentration of Cu and Mn increased. Transferred Zn concentrations to rice grain and shoots of spinach, clover, and grass were more than Cu and Mn and increased in rice grain.     

污水灌溉对土壤浸提液元素浓度变化影响的田间试验研究

土壤化学元素的变化趋势关系到污水灌溉农业的可持续性。该文通过田间试验,研究了冬小麦和夏玉米轮作条件下2种灌溉水质和3种灌水量对土壤浸提液元素浓度变化的影响。试验结果表明：在自然降雨条件下,大水量污灌增加土壤盐分而中、小水量污灌则降低土壤盐分。试验用污水不会导致土壤的次生碱化。土壤中的Ca、Mg、Fe和Zn含量在试验期间增加而P、Mn、Cu、Cd和Ni减小。大水量污灌增加土壤中的Na和B含量而小水量污灌则降低其含量;K的变化趋势与其相反。污灌可补充土壤中的作物营养元素K和P,但降低污水灌水定额可有效抑制盐分、B和Zn在土壤以及重金属元素在作物中的累积。     

MINERAL ELEMENT DISTRIBUTION AND ACCUMULATION PATTERNS WITHIN TWO BARLEY CULTIVARS

Growth stage effects on distribution of mineral nutrients or beneficial elements phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), sulfur (S), chloride (Cl), iron (Fe), zinc (Zn), manganese (Mn), copper (Cu), molybdenum (Mo), sodium (Na), silicon (Si) and nickel (Ni), and the elements bromine (Br), rubidium (Rb), strontium (Sr), barium (Ba), lanthanum (La), cerium (Ce), and uranium (U) in two barley (Hordeum vulgare L.) cultivars and how the distribution of these elements changed were determined during the 2006–2007 growing season in a field experiment. Barley plants were sampled from the field at shooting, heading, soft dough, hard dough and harvest stages, and mineral nutrients and other elements concentrations of spike, flag leaf, old leaf, and stem samples were determined by polarized energy dispersive X-ray fluorescence (PEDXRF). Distribution patterns varied considerably from element to element. At the end of the season much of the Ca, Mg, S, Si, Fe, Mn, Cu, Ni, Sr, Ba, La, Ce, and U were located in the spikes. However, much of the P, K, Zn, Cl, Na, Br, and Rb remained in the old leaves or stem.     

Effect of cadmium toxicity on micronutrient concentration,uptake and partitioning in seven rice cultivars

Heavy metal uptake, translocation and partitioning differ greatly among plant cultivars and plant parts. A pot experiment was conducted to determine the effect of cadmium (Cd) levels (0, 45 and 90 mg kg^?1 soil) on dry matter yield, and concentration, uptake and translocation of Cd, Fe, Zn, Mn and Cu in seven rice cultivars. Application of 45 mg Cd kg^?1 soil decreased root and shoot dry weight. On average, shoot and root Cd concentrations and uptake increased in all cultivars, but micronutrients uptake decreased following the application of 45 mg Cd kg^?1. No significant differences were observed between 45 and 90 mg kg^?1 Cd levels. On average, Cd treatments resulted in a decrease in Zn, Fe and Mn concentrations in shoots and Zn, Cu and Mn concentrations in roots. Differences were observed in Cd and micronutrient concentrations and uptake among rice cultivars. Translocation factor, defined as the shoot/root concentration ratio indicated that Cu and Fe contents in roots were higher than in shoots. The Mn concentration was much higher in shoots. Zinc concentrations were almost similar in the two organs of rice at 0 and 45 mg Cd kg^?1. A higher Cd level, however, led to a decrease in the Zn concentration in shoots.     

Phytotoxizität von Thallium (Tl) in Hydrokultur Teil 1: Einfluß von Tl(I) auf das Wachstum und die Schwermetallgehalte von Erbsen- und Ackerbohnenpflanzen

Phytotoxicity of Thallium (Tl) in Culture Solution Part 1: Effects of Tl(I) on the Growth and Heavy Metal Contents of Pea and Field Bean Plants The effects of TlNO₃ and Tl(I)EDTA on growth and heavy metal contents of pea plants (Pisum sativum L. cv. Aromata) and field bean plants (Vicia faba L. cv. Hangdown) were compared in hydroponic culture experiments. In the presence of TlNO₃, the essential heavy metals were available to the plants in their ionic forms. When Tl(I)EDTA was present the essential heavy metals were available as chelated complexes. TIN03 content of each organ was increased. The highest TI content was found within the stems. The increased TI contents were accompanied by depressed Mn, Zn, and Cu contents of the roots and depressed Mn contents of the stems, but increased Fe contents of the stems. Substitution of TIN03 by TI(1)EDTA resulted in a stronger growth inhibition of the pea plants, and higher TI contents of each organ. The highest TI content was found within the stems. TI(1)EDTA depressed Mn in the roots, but increased Fe and Mn in the stems, and Fe, Zn and Cu in the leaves. The increases may due to concentration by growth inhibition. The growth of the field bean was not effected by TIN03 nor by TI(1)EDTA. The field bean contained most of the TI within the roots and translocated only relatively small amounts to the shoots. This pattern was independent of the TI compound. Increasing concentrations of TIN03 resulted in depressed Mn and Zn contents of the roots, and Mn contents of the stems. Chelation of Tl(1) resulted in a decrease of the TI content of each organ. TI(1)EDTA depressed only the Mn content of the roots.     

Effect of wastewater irrigation on mineral com‐position of corn and sorghum plants in a pot experiment

Effect of wastewater irrigation was investigated on mineral composition of corn and sorghum plants in a pot experiment. The ranges for the concentration of different minerals in corn plants were 0.67–0.89% calcium (Ca), 0.38–0.58% magnesium (Mg), 0.09–1.29% sodium (Na), 0.81–1.87% nitrogen (N), 1.81–2.27% potassium (K), 0.12–0.16% phosphorus (P), 190–257 mg/kg iron (Fe), 3.5–5.6 mg/kg copper (Cu), 37.1–44.5 mg/kg manganese (Mn), 21.6–33.6 mg/kg zinc (Zn), 1.40–1.84 mg/kg molydbenum (Mo), 11.0–45.7 mg/kg lead (Pb), and 2.5–10.8 mg/kg nickel (Ni). Whereas for sorghum plants, the ranges were: 0.56–0.68% Ca, 0.19–0.32% Mg, 0.02–0.27% Na, 0.69–1.53% N, 1.40–1.89% K, 0.10–0.14% P, 190–320 mg/kg Fe, 3.8–6.0 mg/kg Cu, 29.2–37.6 mg/kg Mn, 21.1–29.9 mg/kg Zn, 2.2–3.7 mg/kg Mo, 12.3–59.0 mg/kg Pb, and 2.5–15.2 mg/kg Ni. Heavy metals such as cobalt (Co) and cadmium (Cd) were below detection limits at mg/kg levels. The concentrations of Ca, N, K, P, Cu, and Mn in corn plants were in the deficient range except for Mg, Fe, Zn, and Al. The concentrations of Ca, N, P, K, Cu, Mn, Mg, and Zn in sorghum plants were in the deficient range except for Fe and aluminum (Al). The analysis of regression indicated a strong interaction between Pb, Ni, Ca, and Fe in corn and sorghum plants. In conclusion, waste water irrigation did not increase mineral concentrations of either macro‐ and micro‐elements or heavy trace metals in corn and sorghum plants to hazardous limits according to the established standards and could be used safely for crop irrigation.     

The effect of salinity and iron application on growth and mineral uptake of sunflower (helianthus annuus L.)

In a greenhouse experiment, the effect of salinity and Fe chelate on growth and mineral uptake of sunflower (Helianthus annuus L. c.v. Record) was studied.

Sunflower plants were grown in nutrient solution with four levels of salinity (0, 1.5, 3.0 and 4.5 atm), induced by NaCl and four rates of Fe chelate (0, 0.5, 1.0 and 1.5, ppm Fe) as FeEDDHA. The experiment was a completely randomized design with treatment combinations arranged in a factorial manner with three replications.

Dry matter yield, shoot‐root ratio, leaf area, plant height and transpiration decreased as salinity increased, the effect of salinity being depressed by iron applications. Salinity reduced P, K, Ca and Mg uptake by roots as well as that of N, P, K, Ca, Mg by shoots, while Fe applications increased uptake of these elements in roots and shoots. Both salinity and iron applications increased Cl, Na and Fe uptake by roots and shoots, as expected. In most instances salinity reduced uptake of Fe, Mn and Zn by the plants while iron applications improved uptake of these elements.

The sunflower plant used in this experiment was found to be, at least partly, tolerant to salinity and decreased water availability as well as toxicity of ions. Nutritional disorders were the cause of decreased plant growth by increasing salinity of the nutrient solution. The decreased plant growth and mineral uptake, induced by salinity, were partially offset by increased iron levels in the nutrient solution.     

Production,characterization, and effects on tomato of humic acid-like polymerin metal derivatives from olive oil mill waste waters

The dark polymeric organic fraction rich in potassium recovered from olive oil mill waste waters (OMWW) and named polymerin and the potassium salified deglycosylated polymerin derivative (K-SDpolymerin) were easily transformed into their metal derivatives by saturation with various metals, including Na, Cu, Zn, Mn, Fe, and Al. Saturated metal polymerins were characterized by diffuse reflectance infrared Fourier transform spectroscopy and atomic absorption spectrometry. Tests on tomato plants of the various polymerins showed that only the soluble polymerin, K-SDpolymerin, and the insoluble Mn-SDpolymerin were significantly toxic. The toxic effects of OMWW on tomato at the original concentration and diluted 1:10 were much stronger than those of any polymerin. The possible exploitation of polymerins as bioamendments and/or metal biointegrators as a functon of their phytotoxic effects, their humic acid-like nature, and their richness in macro- and micronutrient metals is also discussed.