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1.
马铃薯对盐碱土壤的反应和适应性研究   总被引:2,自引:0,他引:2  
实验以渭源黑麻土壤(非盐碱土壤)为对照,研究景泰次生盐碱土壤和古浪戈壁残余盐碱土壤对马铃薯形态特征、水势、渗透调节物质含量和K+/Na+选择性吸收的影响。结果表明:(1)土壤盐碱化使马铃薯植株变小、茎变细、叶片变小,主根生长减慢,毛根数增加,匍匐茎数减少;(2)盐碱土壤中,马铃薯水势下降,脯氨酸和可溶性糖累积,Na+吸收增加,K+吸收减少;(3)戈壁残余盐碱土壤对马铃薯生长和渗透调节功能影响比景泰次生盐碱土壤大,w(Na+)/w(K+)和S Na+K+随土壤盐碱化加重而升高。说明盐碱土壤中,马铃薯通过叶片变小,主根变短,毛根数增加等形态结构变化适应盐碱环境;也通过积累脯氨酸、可溶性糖和大量吸收无机离子,增强自身渗透调节能力,适应盐碱胁迫。  相似文献   

2.
秦王川灌区农田土壤盐分离子特征分析   总被引:10,自引:1,他引:9  
引大入秦工程实施以来,秦王川灌区土壤次生盐渍化问题日益成为人们关注的焦点。对秦王川灌区不同时空下的农田土壤可溶性盐分离子特征进行了统计分析以及对比分析,结果表明:秦王川盆地农田土壤八大离子中,阴离子以SO42-浓度最高,CO32-浓度最低,几乎为零,阳离子以Na+浓度最高,K+浓度最低,主要盐分包括Na2SO4、CaSO4、NaHCO3和Ca(HCO3)2等;土壤中不同盐分离子之间存在着一定程度的相关性,体现了盐分的沉积学特征以及其在土壤剖面上的分化关系;土壤的盐分含量在各种因素(灌溉、蒸发、降水以及人为耕作等)影响下,是一个时刻变化的动态过程,这种动态过程可能会在某一时间点达到某种平衡,但这种平衡会被新的因素的加入而打破。  相似文献   

3.
ABSTRACT

Greenhouse experiments were conducted to assess the effects of salinization of soil on emergence, seedling growth, and mineral accumulation of Prosopis cineraria (Linn.) Druce (Mimosaceae). A mixture of chlorides and sulfates of sodium (Na), potassium (K), calcium (Ca), and magnesium (Mg) was added to the soil and salinity was maintained at 5.1, 7.2, 9.3, 11.5, and 13.3 dS m?1. A negative relationship between seedling emergence and salt concentration was obtained. Seedlings did not emerge when soil salinity exceeded 11.5 dS m?1. Results suggested that this tree species is salt tolerant at seed germination and seedling stages. Elongation of stem and root was retarded by increasing salt stress. Young roots and stem were most tolerant to salt stress, followed by old roots and leaves. Leaf tissue exhibited maximum reduction in dry-mass production in response to increasing salt stress. However, production of young roots and death of old roots were found to be continuous and plants apparently use this process as an avoidance mechanism to remove excess ions and delay onset of ion accumulation in this tissue. Plants accumulated Na in roots and were able to regulate transfer of Na ions to leaves. Stem tissues were a barrier for translocation of Na from root to leaf. Moreover, K decreased in root tissues with increased salinization. Nitrogen (N) content significantly (P < 0.01) decreased in all tissues (leaf, stem, and root) in response to low water treatment and salinization of soil. Phosphorus (P) content significantly (P < 0.01) decreased while Ca increased in leaves as soil salinity increased. Changes in elements-accumulation patterns and the possible mechanisms for avoidance of Na toxicity in tissues and organism level are discussed.  相似文献   

4.
为了给艾比湖地区防风治沙及生态恢复工作提供科学依据,以艾比湖主要供给河流——博尔塔拉河下游河岸带土壤为研究对象,对不同植被类型覆盖条件下土壤总盐含量、可溶性离子等指标进行定量测定,并进行相关性分析以及主成分分析。结果显示:研究区土壤盐含量表聚性较强;土壤中的总盐含量与HCO3-,K++Na+存在极显著的正相关关系;HCO3-,Cl-,K++Na+是研究区盐渍化状况的特征因子。研究区土壤次生盐渍化严重,经盐渍化分级为盐土。  相似文献   

5.
滇池流域大棚土壤硝酸盐累积特征及其对环境的影响   总被引:8,自引:2,他引:8  
对滇池流域主要大棚土壤的分析结果表明:随着大棚年限的增长,土壤剖面(0~60 cm)土层中硝态氮在不断累积,加重了土壤次生盐渍化;大棚内0~20 cm、20~40 cm土壤硝态氮含量与全盐的相关性均达极显著水平。同时对大棚区的地下水、地表水的分析结果表明:地下水中NO-3含量与土壤NO-3含量呈正相关,相关系数为0.945**,大棚种植区土壤的NO-3累积严重威胁地下水环境;地表水中的总氮含量与大棚土壤NO-3含量的相关性很好(r=0.994**),大棚种植区土壤的NO-3累积将加重滇池面源污染的负荷。  相似文献   

6.
土壤次生盐渍化与微生物数量及土壤理化性质研究   总被引:7,自引:1,他引:6  
次生盐渍化已成为制约设施栽培农业发展的主要障碍因子,为揭示次生盐渍化对土壤微生物和理化性质的影响,对上海市南汇区和崇明区设施栽培大棚土壤酶活性和微生物活性进行研究.结果表明:随着栽培时间的增加,土壤表层(0-5 cm)有机质变化不明显;而土壤中硝态氮和总盐量增加,连续栽培15年土壤的硝态氮(94.23 mg/kg)是露地表层土的14.8倍,EC值是露地的14.9倍;从第5年起土壤出现酸化现象.次生盐渍化越严重,对土壤脲酶、磷酸酶和呼吸强度的抑制越明显,连续栽培15年土壤脲酶活性受抑制率达到71.8%.EC值、总盐、硝态氮与放线菌、细菌数量都呈极显著负相关,与真菌数量呈显著负相关,最高相关系数达到-0.957.次生盐渍化对于深层土(15-20 cm)的影响没有表层土明显.  相似文献   

7.
电导率(Electrical Conductivity,EC)和结构稳定性阳离子比(Cation Ratio of Soil Structural Stability,CROSS)是评估微咸水对土壤渗透性能影响的重要指标。虽然CROSS全面地考虑了Na+、K+、Ca2+和Mg2+对土壤结构稳定性的复杂影响,但CROSS的离子浓度系数在不同地区的适用性存在差异,有必要根据当地的水质条件确定基于EC和CROSS评估方法的分类标准。该研究旨在分析CROSS替代钠吸附比(Sodium Adsorption Ratio,SAR)评估水质危害的合理性以及其在河套灌区的适用性。在河套灌区不同区域采集73份地下水水样,并采用EC和SAR、EC和CROSS对其进行评估。结果表明,基于2种方法的地下水分类结果中,仅有34.25%的水样分类结果相同,并且不同的CROSS计算方法(基于阳离子相对絮凝能力(Flocculation)的CROSSf、相对分散能力(Dispersion)的CROSSd和优化的(Optimal)CROSSopt)在河套灌区的适用性也不相同。建议采用CROSSd或CROSSopt,并结合土壤盐分和离子浓度评估河套灌区地下水水质。该评估方法更全面地考虑了地下水和土壤中的离子组成对土壤渗透性能的影响,有效避免了不合理的微咸水利用导致的土壤结构恶化等问题,可为微咸水的安全可持续利用提供理论支撑。  相似文献   

8.
不同种植年限大棚菜田土壤水溶性盐分的变化特征   总被引:12,自引:0,他引:12  
采集新乡市不同种植年限大棚菜田、露天菜田及大田土壤共计160个样品,调查分析水溶性盐总量、各盐分离子的变化及土壤pH值。结果表明,大棚土壤在连续种植不同年限后,水溶性盐总量上升幅度与种植年限呈极显著相关(r=0.92**);K+、Na+、Cl-、NO2-、NO3-、SO24-含量与种植年限呈正相关,而Ca2+、Mg2+、HCO3-含量变化与种植年限呈负相关;土壤pH值降低幅度与种植年限呈极显著相关;K+、Na+、Cl-、NO3-、SO42-的含量均与土壤水溶性盐总量呈极显著相关。新乡市大棚菜田土壤中Cl-、NO2-、NO3-含量与pH值变化存在极显著负相关;SO42-含量与pH值变化存在显著负相关;HCO3-与土壤pH值变化存在极显著正相关。新乡市大棚菜田阳离子以K+、Na+为主,阴离子主要以Cl-、NO2-、NO3-、SO42-为主;不同种植年限对大棚土壤盐渍化和酸化有极显著影响,K+、Na+、Cl-、NO2-、NO3-、SO42-则是造成土壤盐渍化的重要原因,Cl-、NO2-、NO3-、SO42-是造成土壤酸化的重要原因。  相似文献   

9.
掌握不同地表覆被类型和微地貌特征下的不同深度土壤盐分空间分布规律,对土壤盐渍化防治具有重要意义。该研究以黄河三角洲入海口为研究区,在分析不同深度土壤全盐量、盐基离子(Ca2+、Mg2+、Na+、SO42-、HCO3-、Cl-)空间变异特征的基础上,通过单因素方差分析不同地表覆被类型和微地貌特征下该区土壤盐分的差异,并通过地理探测器分析地表覆被类型、微地貌对土壤盐分的交互影响。结果表明:1)表层土壤Mg2+变异系数达到1.010 8,为强变异性,其余盐基离子均为中等变异性,且均有强烈的空间相关性,全盐量与盐基离子均呈现沿海向内陆降低的趋势,约有42.57%的地区为轻度盐化土;2)不同地表覆被类型间土壤全盐量与Na+、Cl-具有显著差异;3)不同微地貌类型间Na+、Cl-具有显著差异;不同海拔的深层土壤Na+具有显著差异;4)海拔对土壤全盐量与Na+的解释力最强,地表覆被类型对土壤Cl-的解释力最强;5)坡向和海拔对土壤盐分的交互作用最强烈,q值在0.545~0.708之间,其次是地表覆被类型与坡向,q值在0.521~0.613之间。氯化钠主导该区域土壤盐分空间变异,不同地表覆被类型和微地貌特征下均呈显著差异,表层土壤盐分明显高于深层,坡向与海拔之间的交互作用能够较好地解释该地区土壤盐分空间分布。  相似文献   

10.
The objective was to evaluate the effects of omitting macronutrients in the nutrients solution on growth characteristics and nutritional status of eggplants. The treatments were complete nutrients solution and solutions with nutrient omission: nitrogen (N), phosphorus (P), potassium (K), calcium (Ca), magnesium (Mg), and sulfur (S). The experiment was carried out under greenhouse conditions with three replicates in a completely random design. Plant height, number of leaves per plant, leaf area, relative chlorophyll index, photosynthesis rate, stomatal conductance, dry matter, concentration levels of macronutrients in plant aerial part and root system, and nutritional disorders were evaluated. Omitting elements interfered in the concentration of elements in the various plant tissues and this had as consequences limited vegetative growth, reduced dry matter and led to the development of the typical deficiency symptoms of each element. Although potassium was the most demanded of all elements, nitrogen and calcium were the most growth limiting ones.  相似文献   

11.
设施栽培中逆境对园艺作物生长发育及其病害的影响   总被引:1,自引:0,他引:1  
余海英  李廷轩  周健民 《土壤通报》2006,37(5):1027-1032
根据近年来国内外的相关研究进展,针对设施园艺生产中普遍出现的作物生长不良和病害严重等问题,在分析设施内各环境因子改变的基础上,综述了光照不足、温湿度不适、土壤次生盐渍化、酸化、养分失衡以及土壤生物学环境恶化等设施逆境对作物生长发育及其病害的影响。  相似文献   

12.
Samples from potato (Solanum tubersosum), cauliflower (Bropica Oleracu var. Botryhs), and cabbage (Brassica Olerace var. Capitela) and soil samples were collected from fields receiving sewage sludge loads for a long periods and were analyzed for their total concentration of chromium (Cr), cadmium (Cd), lead (Pb), nickel (Ni), and cobalt (Co) in different plant parts and in soil samples. Estimation of these pollutant elements was also made in the extract of the rooting zone (soil) of these plants. The accumulation of pollutant elements was higher in roots than in leaves and shoots, whereas the soil nearer to the discharge point had the maximum DTPA-CaCl2 extractable pollutant elements and their concentrations diminished with distance. In soil samples, accumulation of the pollutant elements occurred in the order Pb > Cr > Ni > Cd > Co. In vegetables, the rate of accumulation was in the order potato > cauliflower > cabbage. The growth of the vegetable plants on contaminated soil was depressed, young leaves showed marked chlorosis, and brown necrotic spots later developed on almost the entire foliage of plants. With increase in age, the affected leaves had a wilted look. The vegetables growing near the discharge point contained the maximum amounts of heavy metals, which were above toxic limits. Of these elements, the accumulation of Cr by potato was highest.  相似文献   

13.
Abstract

Widespread use of postbloom zinc (Zn) nutritional sprays in tree fruit and nut orchards can lead to substantial surface contamination of apple leaf samples by Zn spray residue, which complicates diagnosis of tree Zn status and Zn nutritional requirements. Detergent washing alone substantially reduced the Zn, iron (Fe), and aluminum (Al) concentrations of Zn‐sprayed Golden Delicious apple (Malus domestica Borkh.) leaves compared to unwashed leaves. Adding a 0.1M HCl washing step further reduced leaf Zn concentration, but had no additional effect of leaf Fe and Al concentrations. There was evidence for nitrogen (N) and sodium (Na) contamination of the leaf samples, possibly from chemical components of the detergent washing solution. The results indicate that the detergent washing is critical for eliminating Fe or Al contamination introduced by dust or soil adhering to leaves collected from trees grown in dusty environments or impacted by soil splash. Adding the acid wash should improve the estimate of the physiologically meaningful Zn concentration in Zn‐sprayed leaf tissue; however, the resulting leaf Zn concentrations may still be biased by a small and possibly variable amount of Zn spray residue.  相似文献   

14.
The leaf nutrient concentrations and the N‐to‐nutrient ratios were analyzed to evaluate the nutritional status of holm oaks (Quercus ilex L.) experiencing various anthropogenic pressures. Leaves (1 year old) of Q. ilex and surface soil (0–5 cm) surrounding the trees were collected at seven natural and seven urban sites in Campania Region (Southern Italy) and analyzed for the concentrations of macro (C, N, P, S) and micronutrients (Mn, K, Na, Cu, Mg, Ca, Fe, Zn). The available soil fraction of micronutrients was also evaluated. The nutrients showed different concentration ranges for the natural and the urban sites in the soil (total and available) and in the leaves, that we reported separately. Organic‐matter content and macronutrient concentrations were higher in the natural soils, while the highest leaf N, S, and P concentrations were found at some urban sites. Concentrations of Cu, Na and Zn both in leaves and soil, and Mg and Fe in leaves from the urban sites appeared to be affected by air depositions. Manganese was the only micronutrient to show higher concentrations at the natural than at the urban sites, both in soil and leaves. For this nutrient, in addition, a relationship between leaf and available soil concentrations was found at the natural sites. The ratios between the concentrations of N and each studied nutrient in the leaves highlighted a different nutritional status between the plants from the natural and urban sites.  相似文献   

15.
黄河三角洲土壤盐渍化与地下水特征关系研究   总被引:14,自引:0,他引:14  
为研究黄河三角洲表层土壤盐分含量与地下水特征的关系,对研究区内土壤盐分含量及地下水进行原位监测,分析土壤盐渍化和地下水特征,并运用灰色关联分析法对地下水埋深、电导率、p H和主要离子含量的关系进行定量分析。结果表明:土壤表层盐分含量均值为3.90~6.31 g kg-1,表层以下土壤盐分含量均值为2.54~3.44 g kg-1,属于中度及以上盐渍化程度;地下水埋深平均值为1.16~1.71 m,普遍较浅;地下水阴离子以Cl-为主,阳离子以Na+为主,两者分别占阴、阳离子总量的比例约为65%。关联分析表明,不同地下水特征指标与土壤表层盐分含量的密切程度不同,同一特征指标与土壤表层盐分含量的密切程度在不同时期间差异显著,总体而言,土壤表层积盐与地下水电导率、Na+、Cl-的关系较为密切,与p H、CO32-和HCO3-之间的关系较弱。在防治土壤盐渍化中,应当加强对地下水电导率、Na+、Cl-的控制与管理。  相似文献   

16.
Rising soil salinity has been a major problem in the soils of Egypt in recent decades. High water tables are also a common problem in intensively irrigated areas and can lead to the development of salinity problems. Results show a high correlation between ETM+ band 3 and salt efflorescence. The ground values have a good correlation (r 2 > 0.65) with estimated values. Results also show a positive correlation (r 2 = 0.84) between the concentration of salt on the surface and water table levels of 70 cm or less. In the area under study, salt accumulation, ground water and inadequate drainage conditions are the major causes of salinization.  相似文献   

17.
河套灌区乌拉特灌域春季土壤盐碱化空间分布特征   总被引:7,自引:6,他引:1  
盐碱化状况是干旱区灌区水盐合理调控及水土资源合理利用的基础。为掌握内蒙古河套灌区下游乌拉特灌域春季耕地土壤盐碱化状况的空间分布,通过野外调查采样和实验室检测,对0~20 cm和20~40 cm土层中的全盐量(Total Salt,TS)、pH值、CO32-、HCO3-、Cl-、SO42-、Ca2+、Mg2+、K++Na+含量、交换性Na+含量、阳离子交换量(Cation Exchange Capacity,CEC)、碱化度(Exchangeable Sodium Percentage,ESP)等反映土壤盐碱化特征的指标进行了测定和计算,采用经典统计学、地统计学和多指标综合评价方法对土壤盐碱化指标的空间分布特征进行分析。结果表明:1)0~20 cm土层中的TS含量更大一些,可溶性盐分离子主要以HCO3-、SO42-、Cl-、Na+为主。HCO3-、CEC、交换性Na+和ESP的变异系数在10%~100%之间,属于中等变异,其中交换性Na+和ESP的变异系数接近100%;TS、Cl-、SO42-和Na+的变异系数均大于100%,属于强变异。2)土壤pH、TS和ESP的空间分布规律基本一致,在东西方向上,各指标西部低,东部高;在南北方向上,中间低,南、北两侧高。土壤pH值基本在7.5~8.5之间,从TS空间分布来看,灌域内有32%的土壤存在盐渍化问题,且以轻度盐渍化土为主,约占26%;从ESP分布来看,有97%的土壤存在碱化问题,其中轻度碱化土约占40%,中度碱化土和碱土均约占23%。因此灌域内土壤碱化问题比盐化问题更为突出。3)通过因子分析得出TS、Cl-、Na+、交换性Na+、ESP和CEC是乌拉特灌域土壤盐碱化程度的主要影响因子,公因子综合得分值在-0.78~3.38之间,公因子综合得分能排除指标间个体差异,比较客观地评价土壤盐碱化整体水平。  相似文献   

18.
刘思义  魏由庆 《土壤学报》1988,25(2):110-118
本研究是根据马颊河流域区域水盐动态监测预报分区定量化的要求进行的室内模拟试验,采用了扰动土的土柱法。试验进行分干土柱的毛管水上升湿润锋的观测与湿土状态的蒸发两个阶段。共3个组合21个处理,在人为控制条件下,仅就地下水(潜水)矿化度、耕层土壤有机质、土体构型等三因素对土壤盐渍化的影响,进行了观测。试验表明:地下水矿化度与土壤积盐量之间存在着极显著的正相关;耕层有机质的含量在1.5%开始有明显的抑制土壤盐渍化的作用;明确了在有粘土夹层的土体中,不能以在风干土柱的毛管水上升速度来推测土壤表层返盐的快慢,而应以在湿润土时,土壤水的蒸发速度为依据。粘土夹层的抑盐作用是随其厚度的增加和层位的升高而加强。  相似文献   

19.
渭北地区农田土壤物理性质对土壤剖面盐分的影响   总被引:1,自引:0,他引:1  
通过网格布点法对渭北地区农田土壤进行采样分析,研究了土壤团聚体、土壤容重、土壤质地对土壤剖面盐分的影响。结果表明:(1)研究区轻度盐渍化面积占46.56%,中度盐渍化占23.01%,渭北地区农田土壤盐渍化程度总体不严重但存在较大潜在风险。(2)各层土壤水稳性团聚体与含盐量呈负相关,容重与含盐量的关系因盐渍化程度不同而在各土层表现出不同的正负效应,土壤质地与含盐量仅在0—20cm土层存在显著相关性。(3)土壤物理性质对含盐量的异位影响与含盐量水平有关。当土壤含盐量1g/kg时,40—60cm容重与20—40cm含盐量为幂函数关系,且呈递增趋势;土壤含盐量在2~4g/kg时,20—40cm容重与0—20cm含盐量为一次函数关系,且呈递增趋势;当含盐量2g/kg时,0—20cm容重与20—40cm含盐量为一次函数关系,且呈递减趋势;含盐量2g/kg时,水稳性团聚体与含盐量呈显著线性负相关。  相似文献   

20.
The effect of chemical effluents discharged from a chemical and fertilizer factory on physicochemical properties of soil and germination and mineral composition of wheat was studied at Varanasi, India. Forty times higher concentration of Na was observed in the effluent than that of the nearby well water. It showed a positive (significant) correlation with Na and a negative (significant) with K and Ca of the soil. Cation exchange capacity (CEC), porosity and water holding capacity were reduced by effluent affected soil. the germination percentage of wheat was negatively correlated with the Na of effluent and Na+Mg/Ca of the soil. A significant (positive) correlation existed between Na of effluent and Na content of the plants. Calcium percentage on the other hand, exhibited a reverse trend.  相似文献   

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