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1.
Both drought and salinity cause nutrient disturbance, albeit for different reasons: a decrease in the diffusion rate of nutrients in the soil and the restricted transpiration rates in plants for drought and extreme soil sodium (Na)/calcium (Ca), Na/potassium (K), and chloride (Cl)/nitrate (NO3) ratios for salinity. The objective of this study was to examine short-term effects of drought and salinity on nutrient disturbance in wheat seedlings. Wheat was grown in a greenhouse in soil under drought and saline conditions for 26 days after sowing. At harvest, shoot biomass and length, and fresh weight and dry weight of the blade and sheath in expanded leaves 3 and 4 and expanding leaf 5 were determined. Mineral elements (K, Ca, magnesium (Mg), phosphorus (P), nitrogen (N), Na, sulphur (S), iron (Fe), zinc (Zn), and manganese (Mn)) in leaf blades and sheaths were also analyzed. At harvest, the reduction in plant height, shoot biomass, and accumulative evapotranspiration under drought was similar to that under salinity as compared with control plants. However, drought decreased the accumulation of all ions in the blade of the youngest leaf 5 compared with the control, whereas there was either an increase or no difference in all ion concentrations under saline conditions. The change in concentration for most ions in the blade and sheath of expanded leaves 3 and 4 varied among control, drought, and salinity plants, which indicated a different competition for nutrients between the sheath and blade of expanded leaves under drought and saline conditions. It can be concluded from this study that ion deficiency might occur in expanding leaves under drought but not saline conditions.  相似文献   

2.
    
Abstract

It has been proposed that salicylic acid (SA) acts as an endogenous signal molecule responsible for inducing environmental stress tolerance in plants. In this study, the effects of seed soaked (1.0 mM for 24 h) and soil incorporated (0.1 mM and 0.5 mM) salicylic acid (SA) supply on growth and mineral concentrations of maize (Zea mays L., Hamidiye F1) grown under either salt, boron toxicity or drought-stressed conditions were investigated. Exogenously applied SA either with seed soaked (SS) or soil incorporated (SI) increased plant growth significantly in all the stresses conditions. Salicylic acid inhibited Na and Cl accumulation in saline conditions, and 0.5 mM of soil incorporated SA decreased B significantly in boron toxicity treatment. Except in drought condition, SA treatments stimulated N accumulation in plants. And P, K, Mg and Mn concentrations of SA received plants were increased in the stress conditions. These results suggest that SA regulates the response of plants to the environmental stresses and could be used as a plant growth regulator to improve plant growth and stimulate mineral nutrient concentrations under stress conditions.  相似文献   

3.
Water stress is one of the major limitations to the agricultural productivity around the globe, particularly in warm, arid and semi-arid regions of the world. Sunflower (Helianthus annuus L.), being a crop with medium water requirements, has the ability to tolerate a short period of drought. However, water stress in the soil as well as inside the plant influences various physiological and biochemical processes. This may inhibit plant growth, decrease developmental activities of the cells and tissues and cause a variety of morphological, physiological and biochemical modifications. Nitrogen (N) is one of the most important mineral nutrients because of its numerous effects on plant growth and yield. A number of fundamental processes such as water and nutrient uptake, protein metabolism, photosynthesis, carbon partitioning, and enzyme and plant hormonal activities are regulated by N. These responses result in profound changes in growth rate, net photosynthate production, plant development, and yield. It is well documented that nutrient uptake of plants is inhibited in dry soils and with expected nutrient deficiencies the normal functioning of the plants is affected. Different strategies are being practiced in the world to cope with the problem of nutrient deficiency under water stress. Nitrogen application either through soil or through foliar feeding is an important strategy to alleviate the adverse effect of drought. Supplemental application of N as foliar fertilization to soil-applied fertilization is important in situation where nutrient supply through soil is limited. Some of the relevant work available about the effect of water stress and nutrient availability in sunflower is reviewed in this paper.  相似文献   

4.
    
Drought and salinity individually or in combination adversely affects growth, development, and yield of sugarcane. Apart from physiological traits, nutrients status was studied in six commercial hybrids subjected to drought, salinity, and salinity + drought. Drought was simulated by withholding irrigation in the field, while salinity and salinity + drought were imposed in microplots. Physiological traits, viz, chlorophyll fluorescence, chlorophyll (SPAD) index, biomass production, and leaf area index, reduced drastically in combined stress as against individual stress treatments. Among major nutrients, phosphorus (P) reduced significantly in all the stress treatments. Similarly, iron (Fe) and Zinc (Zn) reduced due to stress and showed differential response for growth stages. Reduction in cane yield and sucrose percentage in stress conditions warrants supplementation of P, Fe, and Zn.  相似文献   

5.
    
This study aims to describe macronutrient and boron deficiencies in pepper grown in a hydroponic system in the presence of a substrate during the vegetative and fruiting phases. The experiments were carried out into a greenhouse, and consisted of a randomized block design with eight treatments: complete solution (control) and nitrogen (-N), phosphorus (-P), potassium (-K), calcium (-Ca), magnesium (-Mg), sulfur (-S) and boron (-B) deficient solutions, with four repetitions for each assay. Visual diagnoses of certain macronutrient and boron deficiencies can be applied by farmers to aid in soil management, since they are observed in leaves, while N, P, Ca, S and B deficiencies led to roots symptoms. Pepper fruits showed nutritional deficiency symptoms when grown under N, K, Ca, Mg, S and B deficits. The appearance of nutrient deficiency symptoms in pepper plants occurs in the following order: N, K, P, Mg, S, Ca and B.  相似文献   

6.
忻府区土壤养分状况分析及其应用   总被引：3，自引：0，他引：3  
采用全球卫星定位系统(GPS)技术,对忻府区土壤进行了网格取样。通过对2627个土样的化验分析,结果表明,耕层土壤有机质、全N、速效P、速效K较第二次土壤普查都有所增加,其中增加值为有机质3.95 g/kg,全N 0.04 g/kg,速效P 8.73 mg/kg,速效K 9 mg/kg。针对土壤养分和目标产量的情况提出了相应的施肥方案,示范试验表明,平衡施肥对玉米有显著的增产作用,平均增产10%左右,节肥3.4%。  相似文献   

7.
    
The objective of this experiment was to evaluate the effect of foliar fertilization of some micronutrients [i.e., manganese (Mn) and boron (B)] on reproductive yield and fatty acid concentrations of a standard sunflower hybrid (‘NuSun 636') irrigated with different concentrations of saline water made by dissolving sea salt. Reproductive yield showed a significant decrease with the increase in salt in the rooting medium. However, foliar sprays of boric acid (H3BO3) and manganese chloride (MnCl2) showed a significant increase in seed number, seed weight, and oil content of seeds in the nonsaline control, which persisted even under saline water irrigation. An increase under the MnCl2 spray was more than with H3BO3 irrespective of non saline or saline water irrigation. Increasing levels of salinity appeared to be responsible for a decrease in oleic monounsaturated fatty acid concentration and an increase in the linoleic polyunsaturated, palmitic and stearic saturated fatty acid content whereas no significant change was found in linolenic polyunsaturated fatty acid content. Foliar applications of H3BO3 and MnCl2 brought some beneficial alteration in fatty acid concentrations of sunflower. Foliar application of H3BO3 caused a significant increase in palmitic and stearic saturated fatty acids and linoleic polyunsaturated fatty acids in control as well as under saline conditions. Oleic monounsaturated fatty acid concentration showed a decline under H3BO3 treatment irrespective to nonsaline or saline conditions. Foliar applications of MnCl2 increased the concentration of palmitic saturated fatty acid and oleic monounsaturated fatty acid irrespective to the plant growth under non saline or saline conditions. While stearic saturated fatty acid, linoleic and linolenic polyunsaturated fatty acid decreased with the application of manganese as compared to the non sprayed control.  相似文献   

8.
干旱胁迫对玉米根系生长及根际养分的影响   总被引：16，自引：1，他引：16  
通过盆栽模拟干旱试验,测定了干旱胁迫下玉米根系生长情况和根际土壤中速效N、P、K的含量。结果表明,干旱胁迫抑制了玉米拔节期和抽雄-开花期玉米根系的生长,减弱了玉米根系的吸收能力。干旱胁追下玉米根际NH4^＋-N、NO3^--N、速效P和速效K均发生根际富集现象。其中有效N和速效K含量高于正常供水．而速效P却呈现低于正常供水的趋势。干旱胁追抑制玉米根系生长、减弱根系吸收能力是玉米减产的重要原因。  相似文献   

9.
    
Abstract

Magnesium (Mg) is a nutrient that affects the development of plants and is mainly supplied through liming performed to correct soil acidity. By acting on photosynthesis and influencing carbohydrate partitioning in the plant, supplementary Mg supplied through soil or foliar application can increase the yield and quality of potato (Solanum tuberosum L.) tubers. The aim of this study was to evaluate the effect of supplemental Mg fertilization by soil or foliar application on plant nutritional status, tuber yield, and carbohydrate partitioning in potato crops in soil corrected with calcitic and dolomitic limestones. The experiment was carried out in pots under greenhouse conditions with a randomized block design in a 2?×?3 factorial scheme with four replications. Dolomitic limestone application and supplemental Mg fertilization via soil increased the concentrations of this nutrient in potato leaves. Liming with dolomitic limestone reduced the uptake of Ca and K by plants, but supplemental Mg fertilization did not alter the uptake of Ca, Mg or K. Supplemental Mg fertilization did not increase plant growth and tuber yield, even when calcitic limestone was used to elevate the base saturation to 60%; the exchangeable Mg concentration in soil was 9?mmolc dm?3, and the Ca:Mg relationship was 3.7. Liming with dolomitic limestone or providing supplemental Mg fertilization did not increase sugar and starch partitioning to the tubers.  相似文献   

10.
    
Growth and biochemical parameters of leaves, flower buds and flowers of olive (Olea europaea L. cv. Chemlali) treated by foliar biofertilization (T0: untreated trees; T1: rich in nitrogen (N), phosphorus (P), potassium (K); T2: rich in calcium (Ca); T3: application of T1 and T2) were analyzed during the flowering stage. The results showed that T1 resulted in higher contents of leaf N, K, and Na. T1 and T3 resulted in an increase of pigment concentration in leaves. All foliar treatments affected negatively the contents of total polyphenols and orthodiphenols in leaves and flower buds. Lower amounts of individual phenolic compounds were detected in the leaves under all foliar bio-fertilizations and in flower buds of olive trees sprayed with T2 and T3. This decrease is explained by the lower enzymatic activity of l-phenylalanine ammonia-lyase. In flowers, T1 exhibits the highest levels of total polyphenols, o-diphenols, and individual phenolic compounds compared to T0.  相似文献   

11.
  总被引：1，自引：0，他引：1  
Suspensions of insoluble particles are available on the market for foliar fertilizers. The question whether uptake of particles into the leaf interior is possible is under debate. The present study examines stomatal uptake of mineral particles into leaves of Avena sativa after spraying an aqueous suspension of calcium carbonate particles. By choosing a plant species with large stomata, confirming wide open stomata at the time of spraying and using a “super spreading” organosilicone surfactant, conditions were optimized for stomatal uptake. Scanning electron microscopical (SEM) examination confirmed particles in the intercellular spaces mostly in the vicinity of stomata. The number and size of particles was larger if leaves were treated with wide open than with closed stomata. The chemical identity of the particles was examined with electron‐dispersive x‐ray spectrography (EDX), confirming the presence of calcium carbonate particles among other particles of unknown origin. In conclusion, this study provides evidence for surfactant‐assisted stomatal uptake of mineral particles from sprayed suspensions in species with large stomata under specific conditions favoring stomatal uptake.  相似文献   

12.
Abstract

A pot experiment was conducted to investigate the effects of different cadmium (Cd) concentrations of phaeozem on growth and uptake of Cd and mineral nutrient copper (Cu) and zinc (Zn) by three maize genotypes in the mature stage. The results showed that the dry‐matter accumulation of shoots was inhibited by added Cd for Jidan209 and Jitian6, but this did not influence Chunyou30. The root biomasses decreased significantly for Jitian6 and stimulated Jidan209 and Chunyou30. Yields of three genotypes of maize were decreased by increasing soil Cd concentrations. Among them, Chunyou30 had a high tolerance and Jitian6 was most sensitive to Cd. The accumulation order of Cd in different parts of plants was root > leaf > stem > grain. The percentage of absorbed Cd by roots was 70–85% of total absorbed amount. Cadmium uptake by maize in the mature stage had a significant genetic variation: Jitian6 > Jidan209 > Chunyou30 for root, stem and leaf, and Jidan209 > Jitian6 > Chunyou30 for grain, respectively. Increase of soil Cd had no significant effect on Zn concentration of leaves, but there was a significant genetic variation: Chunyou30 > Jidan209 > Jitian6 (P=0.023). Cu concentration of leaves was increased significantly with increase of soil Cd (P<0.01), but no genetic variation was observed.  相似文献   

13.
    
The effects of conventional and organic (manure) fertilization on soils of vineyards were examined in the area of Nemea in southern Greece. The soil properties of the adjacent natural environment (maquis), which served as a control (considering the land use changes as treatments), were also examined and compared with those of the vineyards. The null hypothesis was that there was no difference among them. The results rejected the null hypothesis. It was found that the maquis top soil had the highest C concentration than both types of vineyards and the organic vineyard had significantly higher C concentration than the conventional one. The organic soil N followed the same pattern. The vine leaves (blades) in the conventional vineyards had significantly higher concentrations of Ca, Mg, Mn, and Zn. The average values of Mg and Zn concentrations in leaves in the organic vineyards were below the suggested ranges for nutrient sufficiency in vines and for this reason a foliar application of Mg and Zn is recommended for the organic vineyards. The average berry yield was significantly higher in the conventional vineyards.  相似文献   

14.
    
In order to validate whether optimizing irrigation and fertilization can improve degraded saline soil and increase wheat production, a 4‐year wheat field experiment on saline soil in the Yellow River Delta of China was conducted from October 2013 to June 2017. Eight optimizing treatments including two irrigation applcations of 90 (I90) and 135 (I135) mm/time, four irrigation times: at pre‐sowing, wintering, jointing, filling stages, and two fertilizer rates 225 kg N hm−2‐75 P2O5 hm−2‐150 K2O hm−2 (F312), 225 kg N hm−2‐150 P2O5 hm−2‐75 K2O hm−2 (F321) with two basal/topdressing ratios 1:1 (A11) and 1:2 (A12) were designed compared with no‐irrigation and fertilization (CK) and farmer mode (CM). The optimizing treatment combined I135 with F321 and A12 was the optimal practice for wheat production on degraded saline soil in this region. This treatment significantly decreased topsoil salinity on average by 21.97%, increased wheat grain yield, topsoil total N, available P and K, respectively, by an average of 0.74‐, 0.75‐, 1.13‐ and 0.78‐times, improved water utilization efficiency, water productive efficiency, nitrogen utilization efficiency, phosphorus utilization efficiency, respectively, by average of 1.26‐, 8.13‐, 0.32‐, 0.43‐times compared with the CM. These results demonstrate that the optimization of irrigation and fertilization can be extensively applied as a feasible and effective strategy to improve degraded saline soil, maintain soil nutrients, maximize crop yield, and enhance efficiency in other similar degraded saline soil areas of the world.  相似文献   

15.
变量施肥对玉米产量及土壤养分影响的试验   总被引：13，自引：3，他引：13       下载免费PDF全文
采用自主开发设计的基于GPS和GIS技术的自动变量施肥系统,于2003、2004年间进行了玉米种植条件下变量施肥田间试验。与相邻传统施肥地块相比,变量施肥在一定程度上增加了玉米产量,在合理控制化肥用量的情况下,可以达到既减少投入又增加产量的目的。土壤养分分析结果表明：两年试验前后,变量区与传统施肥区土壤中的碱解氮含量均有所增长,但变量区碱解氮含量的变异系数较传统区减少;变量区和传统施肥区速效磷的含量都有所下降,且变量区较传统区下降明显,变异系数减少;速效钾含量均增加,增加幅度基本一致,但变量区变异系数下降。说明变量施肥具有一定均衡土壤养分的作用。  相似文献   

16.
The purpose of the present work was to evaluate effects of zinc application on growth and uptake and distribution of mineral nutrients under salinity stress [0, 33, 66, and 99 mM sodium chloride (NaCl)] in soybean plants. Results showed that, salinity levels caused a significant decrease in shoot dry and fresh weight in non-zinc application plants. Whereas, zinc application on plants exposed to salinity stress improved the shoot dry and fresh weight. Potassium (K) concentration, K/sodium (Na) and calcium (Ca)/Na ratios significantly decreased, while sodium (Na) concentration increased in root, shoot, and seed as soil salinity increased. Phosphorus (P) concentration significantly decreased in shoot under salinity stress. Moreover, calcium (Ca) significantly decreased in root, but increased in seed with increased salinization. Iron (Fe) concentration significantly decreased in all organs of plant (root, shoot, and seed) in response to salinity levels. Zinc (Zn) concentration of plant was not significantly affected by salinity stress. Copper (Cu) concentration significantly decreased by salinity in root. Nonetheless, manganese (Mn) concentration of root, shoot, and seed was not affected by experimental treatments. Zinc application increased Ca/Na (shoot and seed) ratio and K (shoot and seed), P (shoot), Ca (root and seed), Zn (root, shoot, and seed) and Fe (root and shoot) concentration in soybean plants under salinity stress. Zinc application decreased Na concentration in shoot tissue.  相似文献   

17.
叶面喷施抗旱剂对冬小麦产量及经济效益的影响   总被引：2，自引：0，他引：2       下载免费PDF全文
2011年春季黄淮海冬小麦主产区发生严重干旱,在干旱最严重的河北、河南、山东和安徽等地进行大田试验,探索喷施抗旱剂提高冬小麦抵御干旱、低温、冷冻、干热风等自然灾害能力的技术方法。结果表明:叶面喷施抗旱抗逆制剂能明显提高冬小麦抗旱抗逆能力,在遭受严重干旱的情况下,对比常规对照,喷施抗旱抗逆制剂能增加小麦穗长度,有效穗数增加19.15%,冬小麦平均增产7.3%,增收1 147.5元/hm2。  相似文献   

18.
    
Salinity is a major abiotic stress that limits the productivity of crops, particularly cereal crops, while decreasing nutrient availability, especially of nitrogen. An experiment was conducted to study the effects of salt stress [i.e., S0, S1, and S2 (control, 1.09; 5; and 10 dS m?1)] and four different nitrogen (N) levels [i.e., N0, N1, N2, and N3 (control, 175, 225, and 275 kg N ha?1)] on two maize hybrids, Pioneer 32B33 (salt tolerant) and Dekalb 979 (salt sensitive). The experiment was conducted in a wire house. The experiment was laid out with three factors in a completely randomized design. The plant tissue was analyzed for solute and ion contents. With the increase in salt stress and N rate, solute (i.e., glycinebetaine), protein, total soluble sugar, and total free amino acids accumulated in both hybrids. Nitrate (NO3) and nitrite (NO2) reductase activity decreased sharply at 10 dS m?1 compared to lower levels of salinity but it increased significantly with the addition of N. The uptake of potassium (K+), calcium (Ca2+), magnesium (Mg2+), N, and phosphorus (P) reduced significantly in shoots with increased salinity while the sodium (Na+) and chloride (Cl) contents were increased. It is concluded from the present study that at greater salinity level, hybrid Pioneer32B33 maintained statistically greater solute and ion contents excluding Na+ and Cl ions and significantly decreased enzyme activity. However, these parameters were increased by N rate.  相似文献   

19.
磷、钾肥施用位置对夏玉米苗期生长发育的影响   总被引：4，自引：0，他引：4       下载免费PDF全文
为了探明磷、钾肥对夏玉米苗期生长的位置效应,提高肥料利用效率,通过盆栽试验,探讨了磷、钾肥施用位置对夏玉米苗期干物质累积、养分吸收、根系生长的影响,施肥位置包括种子侧方5 cm、种子侧方10 cm、种子下方5 cm、种子下方10 cm,共4个处理。结果表明,磷肥施用距离对夏玉米苗期生长有较为明显的影响,磷肥近距离施用能够促进玉米根系生长和养分吸收,提高干物质累积量;磷肥施用方位(侧方和下方)对夏玉米苗期生长无明显影响。钾肥不同施用位置对夏玉米苗期干物质累积量和根系长度无明显影响,但对植株根系干重和植株含钾量有一定影响,钾肥近距离施用有减少钾素吸收的趋势。此结果对于玉米苗期的磷、钾养分管理具有一定的指导作用,但是磷、钾肥施用位置对夏玉米整个生育期的影响还有待于进一步研究。  相似文献   

20.
在湖南祁阳国家红壤肥力与肥料效益长期监测基地,于2008年对已有18年旱地红壤肥料试验历史的不施肥、NK、NP、PK、NPK处理下玉米产量、pH以及养分状况等指标进行了研究.结果表明,长期不施磷肥、只施氮钾肥导致玉米绝产.施用磷肥有极显著的增产作用,其中NP、PK与NPK处理分别比不施肥处理玉米增产33.2%、66.39%与151.45%.施磷的增产作用主要体现在玉米穗粒数、百粒重以及公顷穗数的增加.长期施用氮肥造成了土壤酸化,尤以NK处理酸化严重(pH值降至4.1),导致玉米产量连年下降.长期不施磷肥、只施氮钾肥,导致土壤全磷量和有效磷量降低,而全氮、全钾、碱解氮、有效钾量增加,表现为土壤氮磷钾养分比例严重失衡.NK处理的土壤氮磷钾全量比例为2.8:1:44.5,其它施磷处理的为1.09～1.32:1:17.96～19.36;NK处理的土壤氮磷钾速效量为31:1:57,其它施磷处理的为0.7～1.16:1:1.07～4.6.  相似文献   

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