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1.
The main objective of this work was to evaluate the effects of saline irrigation water and leaching on the sugar beet yield components. In a field experiment in Rudasht region (Isfahan, Iran), three irrigation water salinity levels (1.6, 8.1, and 12.3 dS m?1) and with/without leaching were applied. The experimental units comprised of a completely randomized block design, with split plot in four replications. The results indicated that the white sugar yield and alkalinity decreased by increasing the water salinity. Salts leaching significantly increased the root yield, white sugar yield, and white sugar concentration. With higher levels of water salinity molasses sugar, leaf weight, and the concentrations of Na, K, and α- amino-N in sugar beet significantly increased. Consequently, it appears that the use of drainage water in combination with fresh water could be recommended as a strategic management way to grow sugar beet in the investigated arid region. 相似文献
2.
The shortage of good quality water resources is becoming an important issue in arid, semi-arid, and coastal zones. Sugar beet yield declines with an increase in salinity, but its sensitivity to salts varies with the salt composition in water and the plant growth stage. The possible use of Caspian Sea water, which its salinity is well below that of open seas, is desirable for irrigation. The aim of this study was to determine effects of various Caspian Sea water regimes on sugar beet seed germination. A randomized complete block (RCB) design was used with four replications of 15 seeds per pot. Eleven different irrigation treatments of Caspian Sea water ranging from 0% to 100% were applied that each treatment indicates the percent of Caspian Sea water to the mixture with the fresh water. Seed germination percent and the mean time to germination data were obtained for 30 days. Statistical analysis revealed that seed germination was significantly affected by Caspian Sea water, particularly by the salinity levels above the electric conductivity (EC) 13 dSm?1. 相似文献
3.
甜菜是我国及世界主要糖料作物之一,但钾肥的不合理利用严重制约了甜菜生产。以不同甜菜品种为研究对象,探究施用不同钾肥类型及不同钾肥用量对土壤钾素迁移、甜菜块根产量、产糖量及钾肥利用率的影响,以期确定适宜甜菜的钾肥类型及施用量。试验设置2个甜菜品种(KWS9899、KWS7748)、2种钾肥类型(氯化钾和硫酸钾)、4个钾肥施用量(以K2O计0、105、210、315 kg/hm2)。结果表明:(1)在距离滴灌带水平10、20 cm处,两种甜菜均以施用钾肥(K2O) 315 kg/hm2时土壤的速效钾迁移量最大,并且氯化钾肥的速效钾迁移量大于硫酸钾肥。同时,两种肥料类型下土壤中的速效钾均在20~40 cm土层中积累。(2)钾肥会提高甜菜块根产量和产糖量,以施用硫酸钾肥(K2O 210 kg/hm2)的产量与产糖量最高,且两种甜菜钾肥利用效率均随氯化钾肥和硫酸钾肥施用量的增加而下降。综上,施用钾肥可以增加耕层土壤速效钾和全钾含量,进而提高了甜菜块根产量和产糖量,增加了钾肥农学利用率。硫酸钾肥(K2O 210 kg/hm2)对甜菜的块根产量和产糖量增加效果最佳。 相似文献
4.
采用盆栽砂培在室内人工可控和室外自然环境条件下,利用前期研究已经获得的对低磷胁迫抗性弱 (品14)、中(品17)和强(品20)的3类种质材料各1个,进行了长期低磷胁迫(P 1 mol/kg)条件下不同基因型甜菜光合特性的研究。结果表明,1)低磷胁迫显著(P0.05)降低了甜菜叶片无机磷和叶绿素含量,品20的降幅显著低于品14。2)低磷胁迫对3个品种的气孔导度、蒸腾速率均有显著或极显著(P0.01)的负效应;对胞间CO2浓度的效应因品种而异,与P 100 mol/kg处理比,品14显著下降,品17无变化,品20显著增加。3)与P 100 mol/kg处理比,低磷胁迫使3个品种单叶光合速率降幅均达到了极显著水平,但不同品种之间表现各异;品14降幅最大,品20最小,品17居中,且3个品种间的差异均达到了显著或极显著。4)不同生长条件使甜菜对低磷胁迫在单叶光合速率方面产生不同的抵抗能力;在室内培养条件下,同样的磷胁迫水平对各品种甜菜光合作用的阻碍均显著小于自然环境。5)低磷胁迫条件下,甜菜各品种在植株磷含量、气孔导度、蒸腾速率、胞间CO2浓度和单叶光合速率等性状上的抗胁迫指数大小与品种自身的抗低磷胁迫强弱的顺序完全一致,即品20品17品14。 相似文献
5.
为了明确滴施化学改良剂对新疆盐碱土盐碱指标的影响,合理选用化学改良剂,选择4种滴灌专用盐碱改良剂类产品(酸碱平衡护理剂、酸酸肥霸、肽能氮、生物有机菌肥),以不施化学改良剂为对照,对施用前后土壤盐分、pH值、钠吸附比、总碱度、碱化度指标变化和甜菜锤度、产量的差异进行分析。结果表明:与不施化学改良剂相比,酸碱平衡护理剂处理和生物有机菌肥处理使土壤pH值分别降低了0.67和1.03个单位,达到显著水平(P0.05)。除施用酸酸肥霸处理的土壤盐分上升外,其余3种改良剂处理的土壤盐分均下降,施用生物菌肥使土壤盐分下降1.19 g/kg,达到显著水平(P0.05)。施用改良剂使土壤CO_3~(2-)和HCO_3~-的降幅达2.00%~80.00%,酸碱平衡护理剂和肽能氮主要降低土壤中CO_3~(2-)的含量,分别降低了49.50%和30.00%;酸酸肥霸降低HCO_3~-的效应优于CO_3~(2-);生物菌肥对HCO_3~-和CO_3~(2-)均有显著的降低作用,分别下降了60.40%和80.00%。4种盐渍土改良剂均能够有效地降低土壤耕层总碱度和pH值,以生物有机菌肥效果最显著;肽能氮和生物有机菌肥可同时降低土壤钠吸附比和碱化度,显著提高了甜菜的产量,但酸酸肥霸和酸碱平衡护理剂处理的甜菜产量与对照相比差异不显著。 相似文献
6.
《Communications in Soil Science and Plant Analysis》2012,43(6):969-979
Abstract The effects of different kinds and concentrations of salts on dry matter yield and nitrogen (N) and phosphorus (P) contents of rice plants under greenhouse conditions were determined for two silt loam soils, one from southern Ohio (Clermont) and one from Arkansas (Crowley). Yield and N and P contents tended to be enhanced by low salt concentration but to be depressed at higher concentration. The chloride salts (NaCl, CaCl2) were most detrimental to yield and N and P contents, while the sulfate salts (especially Na2SO4,) were beneficial when the electrolyte concentration and P in the soil were not high. The degree of adverse response to salts in the irrigation water and of favorable response to P fertilizer were reflected in the levels of electrolyte and available P in the soils studied. Total N content of the rice tissue increased much more from N and P additions than did total P content. The NaCl (1.5 mmhos/cm) and NaCl + Na2SO4 (3.0 mmhos/cm) salt treatments vere generally least detrimental, and NaCl and NaCl + CaCl2both at 3.0 mmhos/cm were most detrimental to yield and N and P contents of tissue. In the non‐lethal response range, salt‐depression of yield and N and P contents of tissue may well be largely or partially overcome by fertilizer application. In this study, the best combination of fertilizer and salt was the highest level of N (268 kg N/ha) and intermediate level of P (67 kg P/ha), in combination with NaCl + Na2SO4. 相似文献
7.
Background and aims
Increasing demand for lithium (Li+) for portable energy storage is leading to a global risk of Li+ pollution from the manufacture, use, and disposal of Li+-containing products. Although Li+, a reactive alkali metal, has no essential function in plants, they readily take it up and accumulate it in large amounts in their tissues. The underlying mechanisms for this Li+ uptake and accumulation are, however, not well described. Our aim has been to investigate the effects of other alkali metals with similar physicochemical properties on the uptake, accumulation, and toxicity of Li+ at low and high osmolarity.Methods
To determine the way in which Li+ affects the accumulation of other cations under saline conditions, sugar beet plants were grown in hydroponic culture with equimolar amounts of Li+, potassium (K+), and sodium (Na+) at low and high concentrations in various combinations.Results
Sugar beet plants tolerated high Li+ concentrations in the leaf and petiole. Low Li+ concentrations had no impact on plant growth but induced stomata closure. The presence of other monovalent cations at equimolar concentrations did not affect Li+ accumulation, but Li+ application altered the ratio of monovalent and divalent cations in leaves. Plants treated with high Li+ in combination with Na+ or K+ showed reduced plant growth and leaf necrosis, indicating the severe stress caused by Li+ toxicity.Conclusion
The presence of cations with similar physicochemical properties to those of Li+ cannot mitigate its toxicity. 相似文献8.
为探寻干旱区滴灌甜菜氮磷钾最佳施用模式,以KWS9147为材料,采用“3414”试验设计,分析氮磷钾配比对甜菜经济产量的影响。结果表明,不同肥料配比对甜菜块根产量、含糖率与产糖量影响显著。施肥因子对甜菜块根产量的单独效应为氮肥>钾肥>磷肥;对含糖率与产糖量的单独效应均为磷肥>氮肥>钾肥。在本试验中,单独施以足量的氮、磷肥有利于提高甜菜产量。然而,当钾肥(K2O)施入量超过46.74 kg·hm-2时产量下降,施入量超过72.79 kg·hm-2时产糖量下降;磷肥(P2O5)施入量超过35.91 kg·hm-2时块根含糖率下降。氮磷肥配施条件下,在施氮肥(N)0~39.1 kg·hm-2、磷肥(P2O5)0~89.5 kg·hm-2范围内,随着施用水平的增加,甜菜产糖量显著增加。氮磷肥、磷钾肥与氮钾肥互作均可以有效提高甜菜块根含糖率。本试验中施肥配比N∶P2O5∶K2O为2.7∶1∶1.1时,可获得最高产糖量(26772.1 kg ·hm-2)。 相似文献
9.
Irshad Ahmad Bashir Ahmad Shahzad Ali Muhammad Kamran Bayasgalan Bilegjargal 《Journal of plant nutrition》2017,40(15):2109-2115
The objective of this study was to evaluate the effects of organic and inorganic fertilizers on the yield and quality of sugar beet genotypes (Beta vulgaris L.). Therefore, a field trial was carried out in Peshawar, Pakistan, during the winters in 2012–2013. The field experiment was conducted in a randomized complete block design with split plots, having three replications. Fertilizer treatments (control, composted manure Higo Organic Plus at 5 t ha?1, Maxicrop Sea Gold seaweed extract at 5 L ha?1, farm yard manure at 10 t ha?1, inorganic nitrogen–phosphorus (NP) at 90:60 kg ha?1, NP at 120:90 kg ha?1 and NP at 150:120 kg ha?1) were allotted to main plots, while genotypes (Sandrina, Serenada and Kawe Terma) were allotted to the sub-plots. Plots treated with the application of NP at 120:90 kg ha?1 produced the highest beet yield (76.4 t ha?1) and sugar yield (11.1 t ha?1), and had the second highest polarizable sugar content (14.52%) and more economic return (Rs. 553,000 per hectare) as compared to control plots. Sugar beet genotype Serenada had significantly higher beet yield (55.5 t ha?1) and sugar yield (7.9 t ha?1) and a higher economic return (Rs. 380,000 per hectare) than the other genotypes. Sugar beet genotype Serenada supplied with NP at 120:90 kg ha?1is recommended for the general cultivation in the agro-climatic conditions of Peshawar valley. 相似文献
10.
Zahra Abbasi Maryam Golabadi Samar Khayamim Mohammad Pessarakli 《Journal of plant nutrition》2013,36(20):2660-2672
AbstractThirty-four sugar beet drought-tolerant half-sib families were screened in greenhouse experiment under saline (16?dSm?1) and normal conditions, and a subset of 10 tolerant genotypes were selected for evaluating of yield-related traits, Na+, K+, and α-amino-N nitrogen contents under saline field condition (12?dSm?1). Drought-tolerant genotypes showed a different tolerance level under salt stress. Significant correlation was observed between EP2s and STIEP2 in greenhouse with root yield (RY) in saline field condition. It should be possible that a simple measurement at 16?dSm?1 in the greenhouse can be used as main part of sugar beet salt-tolerant breeding program. In total, genotypes SBSI-DR I-HSF14-P.23 (# 16) and 436B-HSF9-P.27 (# 26) were recognized as salt- and drought-tolerant genotypes with low Na+ and K+ contents in root and high white sugar content (WSC) and RY in field. A larger panel of genotypes to validate this kind of association is necessary. 相似文献
11.
《Communications in Soil Science and Plant Analysis》2012,43(17-18):2405-2419
Abstract Salinity and moisture stress are main limiting factors of agricultural development on arid and semi‐arid lands. The objective of this study was to evaluate the tolerance of sesame (Sesamun indicum L.) genotypes to salinity. Salinity treatments in rooting media were 0.5, 2.0, 3.5, 5.0, and 7.0 dS m?1 using calcium chloride (CaCl2). Germination of 50 genotypes was evaluated. Twenty seeds of each cultivar were set in paper towels and moistened with the saline solutions for 15 days. Five germination‐selected genotypes were seeded in 10‐kg pots, and soil salinity was adjusted to the same treatments. Highly significant effects were found for dry matter at 45 (DM 45) days after planting (DAP), at 90 DAP (DM 90), and leaf area (LA). Growth differences among genotypes were only observed for DM 90. These data suggest that sesame tolerance to CaCl2 salinity improved through the growing season and may be genetically controlled. 相似文献
12.
Nobuhiko Fueki Koji Sato Harunobu Takeuchi Hitoshi Sato Satoshi Nakatsu Jun Kato 《Soil Science and Plant Nutrition》2013,59(3):411-420
Studies were carried out on the interaction between potato scab, soil pH and exchangeable calcium in two different fields, one consisting of volcanic ash soil and the other, of red-yellow soil. Severity of potato scab in the field with red-yellow soil was correlated with the soil pH, unlike in the field with volcanic ash soil. The amount of exchangeable calcium in both soils was positively correlated with the scab index of potato tuber, when the content of exchangeable calcium in soil exceeded 150 mg per 100 g soil. From these results, it was concluded that the content of exchangeable calcium is as a more reliable parameter than the soil pH to evaluate the severity of potato scab. 相似文献
13.
Dynamic model for the effects of K-fertilizer on crop growth, K-uptake and soil-K in arable cropping. 1. Description of the model 总被引:1,自引:0,他引:1
Abstract. To provide a practical aid to improving fertilizer practice a mechanistic model was developed that can be readily calibrated for widely different crops. Most of the inputs are easy to obtain and the others, the amounts of fixed soil-K and the velocity constants for fixation and release of soil-K, can be readily measured by a novel procedure which is described.
The model calculates for each day the potential increase in plant weight and the increment in root length, from the current plant mass, its %K and pan evaporation. It calculates the maximum amount of K that could be transported through soil to the root surfaces. It modifies this potential uptake by taking account of the 'feedback' of plant K on root absorption to give the actual uptake and a new %K in the plant. It calculates the radii of the depletion zones around each root increment and the interchange between the solution, exchangeable and fixed-K in these zones and also in the undepleted regions of soil. Routines are included for the effects of weather on the various processes. Differences between species are accommodated by selecting one of three algorithms for root growth and by adjusting the values of two crop-K parameters that define the decline in a critical and a maximum possible %K with increase in plant mass per unit area.
A simplified version of the model runs interactively on the Internet at: http://www.qpais.co.uk/moda-djg/potass.htm 相似文献
The model calculates for each day the potential increase in plant weight and the increment in root length, from the current plant mass, its %K and pan evaporation. It calculates the maximum amount of K that could be transported through soil to the root surfaces. It modifies this potential uptake by taking account of the 'feedback' of plant K on root absorption to give the actual uptake and a new %K in the plant. It calculates the radii of the depletion zones around each root increment and the interchange between the solution, exchangeable and fixed-K in these zones and also in the undepleted regions of soil. Routines are included for the effects of weather on the various processes. Differences between species are accommodated by selecting one of three algorithms for root growth and by adjusting the values of two crop-K parameters that define the decline in a critical and a maximum possible %K with increase in plant mass per unit area.
A simplified version of the model runs interactively on the Internet at: http://www.qpais.co.uk/moda-djg/potass.htm 相似文献
14.
Bernd Steingrobe 《植物养料与土壤学杂志》2001,164(5):533-539
Sugar beet (Beta vulgaris L.) was grown in two different long‐term P fertilization experiments on a sandy and a loamy soil. The P supply levels of the soils were ”︁low”, ”︁sufficient”, and ”︁high”, according to the German recommendation scheme. The low P level decreased shoot and storage root yield only on the loam soil, where the recovery of the P‐deficient plants after a drought period was slower than at a sufficient P supply. The size of the living root system, as determined by a conventional auger sampling method, peaked at early July and decreased until harvest on the sandy soil without any influence of the P level. On loam, the living root systems were more constant and larger at P shortage. Total root production, as determined by the ingrowth core method, was about 120 km m—2 in the well P supplied loam treatments and 200 km m—2 at P deficiency, which was 3—4 times and 5 times higher than the average size of the living root systems, respectively. Hence, a rapid root renewal took place. On sand, where no P deficiency occurred, total root production was not different between the P supply levels but higher than in the well‐supplied loam treatments. Modelling P uptake revealed that this root turnover and the concomitant better exploitation of the soil facilitates P uptake at a low P level in soil, but is of no advantage at a sufficient P supply. The increase of root production at P shortage increased calculated P uptake by 25% compared to a calculation with the ”︁usual” root production at a sufficient supply. 相似文献
15.
Pegah Aqaei Marjan Diyanat Javad Razmi Paul C. Struik 《Journal of plant nutrition》2020,43(9):1205-1216
AbstractTo investigate the influence of potassium nano-silica (PNS) on maize plant under drought stress including non-stress (NS), moderate drought stress (MDS) and severe drought stress (SDS), a factorial experiment was conducted with completely randomized blocks with three replications. Drought stress decreased the concentrations in the shoot of phosphor (P), calcium (Ca), iron (Fe), zinc (Zn), manganese (Mn) and silica (Si) and nitrogen (N), P, Ca, Fe, Zn, copper (Cu), Mn and Si concentrations of seed. There was an increase in the concentration in the N seed and shoot potassium (K) concentration under drought stress. It was observed that applying PNS increased nutrient absorption. The highest concentration of N in the seed was obtained at 100?ppm PNS. The highest concentrations of seed K and N, Cu, Mn and Si in the shoot were found when 200?ppm of PNS was applied. Applying PNS had no significant effect on the concentrations of P, Ca, sodium (Na) and Cu in the seed, and of Ca and Na in the shoot. These findings demonstrate that the application of PNS can limit the negative effects of drought stress and improve plant’s resistance against drought stress. 相似文献
16.
【目的】甜菜属于耐盐碱作物,通过比较两个优质甜菜材料的耐盐性,为甜菜育种提供科学依据。【方法】本试验以甜菜M14品系(18+1条染色体)和来自同一亲本分离得到的二倍体栽培甜菜(18条染色体)为试验材料,在正常和200 mmol/L NaCl胁迫条件下进行水培试验。在处理0、1、3、5、7天后,采集幼苗样品,测定株高、根长,分析K^+、Na^+、丙二醛(MDA)和甜菜碱含量,测定主要抗氧化物酶基因(SOD、CAT、APX、GR)和甜菜碱合成基因(CMO、BADH)的转录水平及以上6个基因编码酶活性。【结果】1)正常条件下,两个甜菜材料的株高和根长均无明显差异;200 mmol/L NaCl胁迫条件下,M14品系的株高和根长均优于二倍体。2)正常条件下,M14品系与二倍体的根吸收K^+和Na^+的能力相似,代谢过程中产生甜菜碱的量相当;200 mmol/L NaCl胁迫条件下,两个甜菜材料根中的K^+、Na^+含量差异不显著,而M14品系根中的甜菜碱含量高于二倍体。3)正常条件下,两个甜菜材料根中的SOD、CAT、APX、GR、CMO和BADH基因转录水平差异均不显著;200 mmol/L NaCl胁迫条件下,M14品系根中的SOD和GR基因转录水平均在第1天时高于二倍体,CAT、APX、CMO和BADH基因转录水平在第3~5天显著高于二倍体。4)正常条件下,两个甜菜材料根中SOD、CAT、APX、GR、CMO和BADH活性差异不显著;200 mmol/L NaCl胁迫条件下,M14品系根中各酶活性均显著高于二倍体。【结论】在200 mmol/L NaCl胁迫条件下,甜菜M14品系根部的甜菜碱含量较高,抗氧化物酶基因转录水平及酶活性均显著高于二倍体,表现出更高的耐盐性。 相似文献
17.
为了探究NaCl+Na_2SO_4胁迫下甜菜根际环境的变化,选用KWS0143和Beta464 2个品种为材料,在盆栽条件下,将Na Cl和Na_2SO_4以摩尔比2∶1混合,按Na占土壤质量百分比为0、0.2%、0.3%和0.4%(S0、S2、S3和S4)设置4个处理,研究不同程度盐胁迫对甜菜根际土壤微生物数量和土壤酶活性的影响。结果表明,胁迫处理下根际土壤真菌、细菌和放线菌数量差异显著,细菌(18.19×10~5~176.23×10~5CFU·g~(-1))放线菌(7.08×10~5~35.18×10~5CFU·g~(-1))真菌(0.18×10~5~0.98×10~5CFU·g~(-1))。同一取样时期,各处理之间比较,土壤脲酶、磷酸酶、过氧化氢酶活性和微生物总量均是S3最高;2个品种的根际土壤微生物数量和酶活性在取样后期差异均显著,KWS0143高于Beta464。相关分析表明,脲酶活性与细菌数量和微生物总量,过氧化氢酶活性与放线菌数量均呈显著正相关。由此可见,一定量的盐胁迫有利于提高甜菜根际土壤微生物数量及酶活性。本研究为调控盐渍土甜菜生长提供了理论依据。 相似文献
18.
A pot experiment was conducted in the wire house of Department of Crop Physiology, University of Agriculture, Faisalabad to evaluate the effect of salinity stress on water relations, nutrient uptake and yield of six local spring wheat cultivars. The seeds were sown in plastic pots (25 × 15 cm) and experiment was laid out in a randomized complete block design in factorial arrangement with three repeats. De-ionized water was used as control treatment while salinity stress was imposed by irrigating plants with sodium chloride (NaCl) solution of 10 mM at tillering, stem elongation, anthesis, and grain development stages. Results of the study demonstrated that salinity stress decreased water potential by 32%, osmotic potential by 12%, and relative water contents by 20% as compared to control treatment. The nitrogen (N) uptake was decreased by 36% under salinity stress, while phosphorous (P) and potassium (K) uptake were decreased by 56% and 42%, respectively. The yield of wheat plants was also significantly reduced under salinity stress. It reduced grain yield by 25% and grain weight by 7%. The response of different cultivars was also different to salinity stress as cultivars ‘Lasani-08’ and ‘FSD-08’ were found to be more tolerant as compared to other cultivars. 相似文献
19.
盐碱地问题的日益严重制约着河套灌区甜菜的发展。前人研究不同改良剂的配施可以改善土壤理化性质,进而提高作物产量和质量,但关于盐碱地甜菜中的研究鲜有报道。因此,2019—2020年在河套灌区盐碱地中施用不同配比腐植酸型改良剂,通过分析不同处理间甜菜产量和质量、各器官生物量、叶面积指数以及土壤中含盐量的变化规律,结果表明,(1)施用腐植酸型改良剂可以提高盐碱地甜菜的产量和质量,甜菜产量、产糖量相较于对照分别增加11.29%~32.54%、13.50%~38.61%,不同配比腐植酸型改良剂的改良效果不同。(2)施用腐植酸型改良剂可以促进甜菜在盐碱地中的生长发育,并提高甜菜植株的光合效率。(3)施用腐植酸型改良剂可以降低当季盐碱地中的含盐量,相较于不施用改良剂的地块土壤含盐量减少0.59~3.17个百分点,从而改善甜菜生长发育的土壤环境。以上结论为揭示改良剂对盐碱地甜菜生物学特性和产量、质量的影响及其对土壤理化性质的改善提供了理论依据。 相似文献
20.
Amal A. H. Saleh Sayed A. El-Meleigy Fawzia A. Ebad Mohamed A. Helmy Georg Jentschke Douglas L. Godbold 《植物养料与土壤学杂志》1999,162(3):275-279
Seedlings of sugar beet (Beta vulgaris) were grown in nutrient solutions containing a range of Cu and Zn concentrations. Based on measurements of shoot and root length and dry weight, copper was found to be already toxic at 10 μM, while Zn became toxic at 100 μM. At Cu and Zn levels found to induce a similar level of growth inhibiton, the influence of increasing the supply of K, Ca and Mg was investigated. Increasing the concentration of both Ca and Mg in the nutrient solution attenuated the degree of inhibition of root growth by Zn, but not Cu. Potassium did not affect the toxicity of either Cu or Zn. An increase in Ca decreased the level of both Cu and Zn in roots. Magnesium ameliorated the toxicity effects of Zn without effecting the Zn concentration in the roots. Treatment with Zn significantly decreased the concentration of Mg in the roots. An increased supply of Mg lowered the percentage decrease in root Mg concentration due to Zn toxicity. The maintenance of an adequate Mg level in the roots may be critical to prevent Zn induced inhibition of root growth. 相似文献