Micronutrient deficiencies and toxicities of cassava plants grown in nutrient solutions. I. Critical tissue concentrations

The programmed nutrient addition technique was used in a series of 5 experiments to determine the response in growth and micronutrient content of cassava (Manihot esaulenta Crantz) cv. M Aus 10, to 8 supply levels of boron, copper, iron, manganese and zinc respectively. The experiments were of 9 weeks duration and utilized 22 litre pots of nutrient solution. The supply levels for each micronutrient covered the range from severe deficiency to toxicity. Critical tissue concentrations for deficiencies determined by relating total dry matter production to the nutrient concentration in the youngest fully expanded leaf blades were (μg/g): boron 35, copper 6, manganese 50, and zinc 30. Likewise, critical concentrations for toxicities in the same index tissue were (μg/g): boron 100, copper 15, manganese 250, and zinc 120. In the iron experiment, the data were too variable to allow precise determination of critical concentrations for deficiency and toxicity. Critical micronutrient concentrations in the petioles of the youngest fully expanded leaves were also determined, but offered no advantage over the leaf blades.     

Interaction between Plant Nutrients: II. Effect of Chloride on Activities of Cations in Soil Solution and on Nutrient Uptake by Plants

Abstract

In soil solutions the sum of cations is equivalent to that of anions. Anions are soluble or precipitated as less soluble salts. Therefore, the sum of soluble anions are responsible for the sum of cations in the soil solution. Soluble nitrate anions are unstable as they immobilize in biological materials. Hydrogen carbonate is excreted from plant roots and decomposes into carbon dioxide and carbonate. Carbonate reacts with hydrogen ions and forms complexes and ion pairs with calcium ions. Sulphate and chloride are more stable in the soil solution as anions.

Chloride ions were found to increase the activity of cations in the soil solution and to increase uptake of cations through the entire growth period. Increased absorption of cations increased yield. In temperate climate regions the surplus of chloride leaches from the root zone during winter.     

The Effect of Chloride on Yield and Nutrient Interaction in Greenhouse Tomato (Lycopersicon Esculentum Mill.) Grown in Rockwool

The effect of increasing chloride content in nutrient solution on nutrient composition in root environment, interaction of nutrients in leaves and yield of greenhouse tomato cv. ‘Grace F₁’ grown in rockwool were searched. In Experiment I (2004–2005) the levels of 15, 30, 60, and 90 mg Cl·L^?1 but in Experiment II (2006) 30, 60, 90 and 120 mg Cl·L^?1 of nutrient solution were tested. The sources of chloride were water (9.6–10.7 mg Cl·L^?1) and calcium chloride (CaCl₂·2H₂O) but the rest of nutrients and sodium in all treatments were on the same levels. It was found that increasing content of chloride from 15 to 60 mg Cl·L^?1 enhanced the total and marketable fruit yield. Within the range of 60 to 90 mg Cl·L^?1 the yield was on the optimum level but the content of 120 mg Cl·L^?1 declined it. Increasing chloride content in the nutrient solutions was reflected in rising of chlorine content in leaves. The concentration of chloride above 60 mg C·L^?1 reduced the content of nitrogen but above 90 mg C·L^?1 declined the content of calcium, sulfur and zinc in leaves. The antagonism between Cl:N, Cl:Ca: Cl:S and Cl:Zn was appeared. More variable interaction were between Cl:K and Cl:B. At the low levels of chloride, from 15 to 60 mg Cl·L^?1, potassium and boron content were decreased but at the higher ones, from 90 to 120 mg·L^?1, these nutrients had increasing course. It was not found out the effect of chloride contents on macro and microelement contents in nutrient solution emitted from drippers however their content upraising in root medium (rockwool). The highest increase was found out for Na 95.1 and 64.9 % (Exp. I and II - respectively), next for Ca (76.0, 70.1 %), Cu (62.5 and 71.0 %), Cl (43.6, 24.4), B (33.3, 21.0 %), N-NO₃ (30.4, 49.6 %), Zn (29.5, 32.8 %), S-SO₄ (25.9, 25.5 %), K (24.5, 24.1 %), Fe (19.8, 19.2 %), Mn (17.5, 21.3 %) and Mg (14.9, 11.7). Advantageous effect of chloride on tomato yield justified the need to introduce for the practice adequate chlorine nutrition, and recommend to maintain 60 to 90 mg Cl·L^?1 in nutrient solution. The best yield appeared when content of chlorine in leaves (8th or 9th leaf from the top) was in the range 0.48-0.60 % of Cl in d. m.     

深松对玉米产量和养分吸收的影响

为了研究深松对我国玉米主产区产量、养分吸收利用以及土壤养分分布的影响,于2011—2014年在我国东北、华北以及西北地区的9个试验站进行深松改土与常规旋耕对比的联网试验。结果表明,相比于传统耕作,3个区域深松均表现出了增产趋势,产量增加的中值为5.8%,其中,东北和西北区域的增产幅度高于华北区域,而东北区域秋季深松增产的变异低于春季深松。相比于常规旋耕,深松对玉米植株地上部氮和磷的吸收有显著的促进作用,在东北、西北和华北区域深松处理的地上部吸氮量和吸磷量均有所增加,中值分别为24%,5%和10%以及17%,8%和19%。深松处理增加了东北和西北区域土壤表层(0—15cm)和亚表层(15—25cm)的有效磷含量,而在华北区域没有趋势性变化。     

镁、钾营养及其交互作用对水稻产量、产量构成因素和养分吸收的影响

在温室条件下,采用土壤盆栽方法研究了Mg,K营养及其交互作用对水稻(Oryza sativa L.)产量、产量构成因素和养分吸收的影响。结果表明,不同Mg,K施用量均显著地影响水稻籽粒产量及其构成因素,而且Mg,K营养之间存在显著的互作效应。适量施用Mg,K肥就能显著地增加水稻产量,中Mg高K施用量的产量最高,比不施肥增产28.4%。当土壤在低K施用量时,有利于水稻植株对Mg,N和P的吸收;但在高K施用量下,则抑制Mg,N和P的吸收。在低K和中K施用量时,低量Mg能促进N,P.K的吸收,而高Mg施用量则抑制P和K的吸收。水稻秸秆Mg含量随Mg施用量的增加而增加,但随着K施用量的增加而降低。本研究表明,Mg,K营养之间存在较强的拮抗效应,Mg,K肥的平衡施用对提高水稻产量具有重要意义。     

Grain Yield,Quality, and Nutrient Concentrations of Feed,Food, and Malt Barley

Barley (Hordeum vulgare L.) is a cereal grown for animal feed, human consumption, and malting. Nutrient concentrations are important as they provide information regarding the dietary values of barley consumed by animals or human beings. In addition, grain nutrient removal may be useful for refining fertilizer recommendations. A study was conducted in 2015 and 2016 investigating the cultivar effects on grain yield, quality, and grain nutrient concentrations and removal under irrigated conditions for two-row barley cultivars. Adjunct and feed cultivars produced the highest yields compared with the all-malt and food cultivars. Specific quality and nutrient values were greater than or equal to in the food cultivar compared to the malt or feed cultivars. Variations in nutrient concentrations were measured among the adjunct and all-malt cultivars, which could potentially affect the malting and brewing qualities. Grain yield, quality, nutrient concentrations and nutrient removal varied among cultivars grown under identical environmental conditions, which may influence end-use.     

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.     

免耕留茬覆盖对旱作燕麦土壤养分及微生物量的影响

以旱作燕麦田为试验对象,设置免耕高留茬高覆盖、免耕低留茬高覆盖、免耕高留茬低覆盖、免耕低留茬低覆盖和常规耕作5个处理,研究了免耕留茬覆盖对土壤养分、微生物量及燕麦产量的影响。结果表明,免耕留茬覆盖各处理均能明显提高土壤0—10cm和10—20cm土层中土壤有机质、全量养分及速效养分含量,0—10cm土层各土壤养分含量均高于10—20cm土层;免耕留茬覆盖对土壤微生物碳、氮具有显著的提高作用,整个生育期抽穗期达到最大值,0—10cm土层土壤微生物量碳、氮均大于10—20cm土层,其中免耕高留茬高覆盖处理效果最佳;免耕留茬覆盖对0—10cm和10—20cm土壤微生物商有显著提高作用,免耕留茬覆盖处理间差异不显著;免耕留茬覆盖对燕麦产量影响显著,其中高留茬高覆盖处理产量最高,为2 111.4kg/hm~2,较常规耕作增产18.6%,产量总体表现为免耕高留茬高覆盖免耕低留茬高覆盖免耕高留茬低覆盖免耕低留茬低覆盖常规耕作。     

Differential Zinc Efficiency of Barley Genotypes Grown in Soil and Chelator-Buffered Nutrient Solution

Genotypic variation to zinc (Zn) deficiency in barley indicates that selection for Zn efficiency is possible. Sahara (Zn-efficient) and Clipper (Zn-inefficient) were evaluated at different Zn nutrition in soil and chelator-buffered nutrient. Zinc deficiency symptoms appeared first in Clipper and later in Sahara. At 0.8 mg Zn/kg soil, shoot and root Zn concentration and content were higher in Sahara than Clipper. The root:shoot dry matter ratio of genotypes increased as Zn application decreased. The 4th and 5th leaf elongation were depressed greater in Clipper than Sahara by Zn deficiency. The genotypes responses to Zn in solution and soil were consistent in all parameters except root growth. In contrast to soil, root drymatter was greater in Clipper than Sahara in solution under Zn deficiency. Shoot Zn concentration and content can be used in assessment of barley genotypes, and may be useful criteria in screening large genotypes aimed at developing molecular markers for Zn efficiency.     

Cadmium and Nutrient Heavy Metals Uptake by Rice,Barley, and Spinach as Affected by Four Ammonium Salts

This experiment was conducted to investigate the influence of ammonium salts on the uptake of cadmium (Cd) and nutritional heavy metals (copper (Cu), zinc (Zn), manganese (Mn), and iron (Fe)) by rice, barley, and spinach. These plants were grown in Cd, Cu, and Zn contaminated entisol (ES) or andisol (AS). The following ammonium salts were used: ammonium nitrate (NH₄NO₃), ammonium sulfate ((NH₄)₂SO₄), ammonium chloride (NH₄Cl), and ammonium dihydrogen phosphate (NH₄H₂PO₄). In ES, the Cd concentrations in three plant shoots were higher with NH₄Cl than with the other salts. The concentrations of Cd in soil solutions collected from ES were higher with NH₄Cl. Thus, the increase of Cd uptake by three plants with NH₄Cl treatment would be caused by the increased concentration of Cd in the soil solution. In contrast, in AS, the concentrations of the heavy metals in the shoots of all plants were not different among NH₄ applications, with one exception, the Mn concentration in rice increased with NH₄Cl in both ES and AS.     

Soil Solution Aluminum,and Nutrient and Aluminum Uptake in Hibiscus Sabdariffa Under Nitrogen and Phosphorous Fertilizers

The result of intensive agriculture in cities is the decline in crop yields and depletion of the resource base. The aims of this study were to assess effects of nitrogen (N) or phosphorus (P) fertilization on bioavailable aluminum (Al) and their contribution on Al and nutrient uptake in Hibiscus sabdariffa. A pot experiment was led to supply a tropical soil with N and P fertilizers. P amendment decreased Al in soil solution, not N amendment. Fertilizers had effects on Al and nutrient uptake in roots and leaves of Hibiscus sabdariffa. The results also showed that the uptake of Al and nutrients depends on Al in soil solution or N supply or P supply. Only P uptake in roots and leaves was explained by combined effects of a nutrient supply × exchangeable Al. Furthermore, P supply does not limit the translocation of Al in shoots of plants in acid soils.     

Effects of Mycorrhizae and Fertilization on Soybean Yield and Nutrient Uptake

Soybean (local variety Ar?soy) was grown for 45 days on calcareous Karaburun and Menek?e soils. Mycorrhizal inoculation significantly increased both shoot and root yields in the soils. Sulfur (S) fertilization alone did not affect the shoot and root yields in Karaburun soil, whereas there was a great increase in the shoot yield and relatively smaller increase in the root yield for nonmycorrhizal treatments in Menek?e soil. The combination of mycorrhizae and S in Menek?e soil resulted in a yield less than that obtained for mycorrhizae treatments alone. There was a fluctuation in shoot and root yield upon S and/or phosphorus (P) fertilization. There was an accumulation of magnesium (Mg) and zinc (Zn) in the mycorrhizal treatments, whereas there was a dilution of those elements upon yield increases in the nonmycorrhizal treatments. Apart from those, co-application of mycorrhizae, P, and S, resulted in the greatest root yields in both soils, indicating the potential to increase the shoot yield, too, in a longer growth period.     

Interactive Effect of Rhizotrophic Microorganisms on Growth,Yield, and Nutrient Uptake of Wheat

The interactive effect of rhizotrophic microorganisms on growth, yield, and nutrient uptake of wheat (Triticum aestivum L.) was determined in a pot experiment using sterilized soil deficient in available phosphorus (P). Positive effect on plant vigor, nutrient uptake, and yield in wheat plants was recorded in the treatment receiving mixed inoculum of nitrogen-fixing Azotobacter chroococcum + phosphate solubilizing microorganism (PSM) Pseudomonas striata + arbuscular mycorrhizal (AM) fungus Glomus fasciculatum. The available P status of the soil improved significantly (P ≤ 0.5) following triple inoculation with A. chroococcum, P. striata, and G. fasciculatum. The residual nitrogen (N) content of the soil did not change appreciably among the treatments. Addition of Penicillium variable to single- or double-inoculation treatments negatively affected the measured parameters. The population of A. chroococcum, PSM, percentage root infection, and spore density of the AM fungus in inoculated treatments increased at 80 days of wheat growth. The present finding showed that rhizotrophic microorganisms can interact positively in promoting plant growth, as well as N and P uptake, of wheat plants, leading to improved yield.     

Assessment of ZN Interaction with Nutrient Cations in Alkaline Soil and its Effect on Plant Growth

An experiment was conducted to assess the zinc (Zn) availability to wheat in alkaline soils during Rabi 2009–2010. Wheat seedlings in pots having 2 kg alkaline sandy soil per pot were treated with 5, 10 and 15 kg Zn ha^?1 as soil and with 0.5 and 1.0% zinc sulfate (ZnSO₄) as foliar application. Results showed that Zn increasing levels in soil helped in phosphorus uptake up to boot stage but its conversion to grain portion lacked in Zn treated plants. Potassium (K) uptake also increased up to 6.24% in boot stage with treatment of 10 kg Zn ha^?1 + 1.0% ZnSO₄ foliar spray. Zinc (Zn) concentration increased in plant tissues with the increasing level of Zn application but this disturbed the phosphorus (P)-Zn interaction and, thus, both of the nutrients were found in lesser quantities in grains compared to the control. Despite of the apparent sufficient Zn level in soil (1.95 mg kg^?1), improvement in growth and yield parameters with Zn application indicate that the soil was Zn deplete in terms of plant available Zn. The above findings suggest that the figure Zn sufficiency in alkaline soil (1.0 mg kg^?1) should be revised in accordance to the nature and type of soils. Furthermore, foliar application of Zn up to 1.0% progressively increased yield but not significantly; and it was recommended that higher concentrations might be used to confirm foliar application of Zn as a successful strategy for increasing plant zinc levels.     

Interactions Between Sulfur and Selenium Uptake by Corn in Solution Culture

Interactions between sulfur (S) and selenium (Se) uptake and accumulation in corn (Zea mays) plants were investigated in solution culture. Two concentrations (5 and 10 μ M) of Se (as selenate) and three concentrations of S (as sulfate) (0.5, 1.5, and 2.5 mM) were used. Results showed that shoot and root biomass were affected significantly by different S concentrations in solution, but not affected by Se application when S concentrations in solution were lower than 1.5 mM. Selenium concentrations as well as Se accumulation in shoots and roots on a dry weight basis increased dramatically with increasing Se concentrations in solution. At a constant Se level, increasing S in solution reduced Se concentrations. Selenium accumulation in plants was not affected by S application, except in nutrient solution with Se at a concentration of 10 μ M. Sulfur concentrations and S accumulation in shoots increased significantly with increasing Se concentrations in solution, while those in roots were unaffected by Se addition. Solution-to-shoot transfer factors and shoot-root distribution coefficients of Se and S were also discussed. These data suggest that it is necessary to manage carefully both S and Se levels in solution or in soils for supplementation of Se in plants. Results from this study indicate that human Se nutrition can be improved by supplementation of Se in crops.     

Effects of Arbuscular Mycorrhizal Inoculation and Phosphorus Application on Yield and Nutrient Uptake of Yam

To be sustainable, production in the traditional yam cropping system, faced with declining soil fertility, could benefit from yam–arbuscular mycorrhizal (AM) symbiosis, which can improve nutrient uptake, disease resistance, and drought tolerance in plants. However, only limited information exists about AM colonization of yam. A pot experiment was conducted to collect information on the response of two genotypes (Dioscorea rotundata accession TDr 97/00903 and D. alata accession TDa 297) to AM inoculation (with and without) and phosphorus (P) (0, 0.05, 0.5, and 5 mg P kg^–1 soil). Factorial combinations of the treatments were arranged in a completely randomized design with four replicates. The percentage of AM colonization was significantly lowered at 5 mg P kg^–1 soil rate in mycorrhizal plants of both genotypes. TDr 97/00903 showed more responsiveness to AM inoculation than TDa 297. The greatest AM responsiveness for tuber yield (52%) was obtained at 0.5 mg P kg^–1 soil rate for TDr 97/00903. Mycorrhizal inoculation significantly increased root dry weight and tuber yield of TDr 97/00903 with the greatest values obtained at the 0.5 mg P kg^–1 soil rate. Arbuscular mycorrhizal inoculation did not lead to significant (P < 0.05) changes in root length and area. Phosphorus application significantly increased the shoot dry weight and root diameter of TDa 297. Uptake of P was greatest at 0.5 mg P kg^–1 soil in both genotypes and was significantly influenced by AM inoculation. Nitrogen (N) and potassium (K) uptake were greatest in mycorrhizal plants at 0.05 mg P kg^–1 soil for TDr 97/00903 but at 0.5 mg P kg^–1 soil of nonmycorrhizal plants of TDa 297. The increased tuber yield and nutrient uptake observed in the mycorrhizal plants indicate the potential for the improvement of nutrient acquisition and tuber yield through AM symbiosis.     

Effects of Lead,EDTA, and IAA on Nutrient Uptake by Alfalfa Plants

ABSTRACT

The element concentrations of alfalfa plants exposed for 10 d to 40 mg lead (Pb) L^{? 1} from lead nitrate [Pb(NO₃)₂] alone, or combined with ethylenediaminetetraacetic acid (EDTA) and indole-3-acetic acid (IAA), was determined by inductively coupled plasma-optical emission spectroscopy (ICP-OES). Indole-3-acetic acid at 10 μ M and Pb/EDTA/IAA at 10 μ M increased potassium (K) concentration in roots by 87% and 94%, respectively (P < 0.05). However, IAA at 100 μ M decreased K concentration in leaves (P < 0.05). Plants exposed to 100 μ M IAA, Pb/IAA at 100 μ M, and Pb/EDTA/IAA at 100 μ M had, respectively, 30%, 55%, and 40% more sulfur (S) in leaves than control plants (P < 0.05). Lead and Pb/IAA reduced Ca concentration in stems and leaves (P < 0.05). Conversely, Pb and Pb/EDTA increased Cu concentration in roots and stems. IAA at 100 μ M, Pb, and Pb/EDTA/IAA decreased Zn concentration in roots (P < 0.05). Manganese (Mn) and molybdenum (Mo) concentration in roots and stems was lower in plants treated with Pb and Pb/IAA (P < 0.05). Pb and Pb/IAA reduced (P < 0.05) the iron (Fe) concentration in roots. However, the addition of EDTA and IAA at 10 μ M reduced the negative effects of Pb on Fe absorption.     

Salinity Effects on Yield and Yield Components of Contrasting Naked Oat Genotypes

ABSTRACT

Global crop production systems are challenged by the increasing areas of saline soil in arid and semi-arid regions. Two naked oat (Avena sativa L.) lines (‘VAO-7’ and ‘VAO-24’) with distinct seedling tolerance to salinity were subjected to six levels of salt concentrations in a controlled greenhouse, and the response of yield and yield components to salinity stress was determined. The salt treatments 50, 100, 150, 200, and 250 mM sodium chloride (NaCl) (corresponding to EC: 3.42, 6.74, 9.66, 12.40, 15.04 dS m^?1) imposed through modified Hoagland solution. Plain Hoagland was used as control. Complete nutrient elements were provided during the entire growth period. At maturity, the number of tillers with emerged heads was counted; the plant was then harvested and separated into shoots, seeds, and roots. Both plant height and days to maturity were shortened with increasing salt stress. Among the yield components, spikelet, tiller number, and grain dry weight per plant were significantly reduced by increasing salt concentration. Number of spikelets and grain weight per plant were the most salt-sensitive yield components. Thousand grain weight also varied as salinity stress increased. Harvest index remained relatively unchanged until the salinity reached 150 mM and higher. Our data indicate that grain yield reduction in oat due to salinity stress is associated with reduced number of grains per plant and mean grain weight.     

Yield and Nutritional Status of Cucumis sativus under Different Growing Conditions in the Pacific Coast of Ecuador

The growth of cucumber under open field conditions in the coast of Ecuador results in low yields being the growth under protected conditions a tentative solution, but there is little information about the nutritional status of this crop in this region. The objectives were to determine the yield, nutritional status as well as the water and nutrient use efficiencies. The different growing conditions were: multitunnel greenhouse with soilless system (GSL), multitunnel greenhouse with soil system (GS) and open field conditions with soil system (OFS). Cucumber plants grown under GSL had the highest yield. The nutrient concentration in leaf showed different trends: nitrogen (N), calcium (Ca) and iron (Fe) remained unchanged. Phosphorus (P), potassium (K), magnesium (Mg), copper (Cu), zinc (Zn) and manganese (Mn) showed variations according to the growing conditions and phenological stages. The highest values of water and nutrient use efficiencies under GSL were related to the highest yield.     

Influence of Biomass Partitioning and Nutrient Uptake on Yield of Arecanut Grown on a Laterite Soil

The present investigation was conducted on a laterite soil to study biomass partitioning and nutrient-uptake pattern in the aboveground parts of arecanut palm and their relationships to yield. Total biomass production was significantly greater in high-yielding plants (43.6 kg palm^?1) than in low-yielding plants (30.8 kg palm^?1). Total standing biomass of trunk accounted for 69–74% of the total aboveground biomass in arecanut palm. Dry-matter partitioning to kernel was only 4–10% of the total biomass. The uptake of major nutrients varied significantly between low- and high-yielding plants. Calcium (Ca) uptake was greater by trunk than by other parts, while magnesium (Mg) accumulation was similar in trunk and leaf. The uptake of micronutrients by aboveground parts except leaf was significantly different between low- and high-yielding plants. The present study indicated that combined effect of greater biomass production and nutrient uptake had direct impact on marketable yield of arecanut.