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1.
玛纳斯河流域绿洲土壤春季盐渍化研究   总被引:1,自引:0,他引:1  
运用经典统计学和冗余分析方法,对玛纳斯河流域绿洲土壤全盐量(TS)、pH、电导率(EC)、钠吸附比(SAR)和盐分离子组成的空间分布特征进行了分析。结果表明:土壤全盐量呈现明显的底聚特征,各层土壤全盐量均值在5.80~9.02 g•kg-1,表现为轻度至中度盐化;各层土壤中,pH在8.2~8.4、EC在0.70~1.38 mS•cm-1、SAR在0.25~0.64,未出现碱化现象。冗余分析表明:不同层次土壤中,Ca 2+与SO 42-、Na+与SO42-保持较好的关联性。TS的空间分布,在 0 ~70 cm 全剖面上主要受控于Na+、SO42-、Ca 2+和Mg 2+;分层与全剖面的情况略有不同,但Na+、SO42-在各个土层仍为最主要的控制离子。EC在全剖面上的空间分布受控于 Na+、SO42-;50 ~70 cm 土层主要受Na+与Cl-的控制,其他土层与全剖面相同。 pH受控于CO32-;除0~10 cm土层受HCO-3影响外,其他土层与全剖面相同。SAR在全剖面的空间分布受环境因子的影响较小,除50~70 cm土层受Cl-因子的制约外,0~50 cm土层未表现出明显的控制因子。  相似文献   

2.
The farming–pastoral ecotone in northern China is an extremely fragile ecological zone where wind erosion of cropland and rangeland is easy to occur. In this study, using a portable wind tunnel as a wind simulator, we conducted field simulated wind erosion experiments combined with laboratory analysis to investigate wind erosion of soils in trampled rangeland, non-tilled cropland and tilled cropland in Yanchi County, China. The results showed that compared with rangeland, the cropland had a higher soil water holding capacity and lower soil bulk density. The wind erosion rate of trampled rangeland was much higher than those of non-tilled cropland and tilled cropland. For cropland, the wind erosion rate of the soil after tilling was surprisingly less than that of the soil before tilling. With increasing of wind speed, the volume mean diameter of the eroded sediment collected by the trough in the wind tunnel generally increased while the clay and silt content decreased for all soils. The temporal variation in wind erosion of the trampled rangeland indicated that particle entrainment and dust emission decreased exponentially with erosion time through the successive wind erosion events due to the exhaustion of erodible particles.  相似文献   

3.
脱硫石膏对苏打盐碱土水盐入渗过程的影响   总被引:2,自引:0,他引:2  
为研究脱硫石膏对苏打盐碱土水盐入渗过程的影响,2020年6月进行了一项室内土柱入渗试验,供试土壤离子组成主要为Na_2CO_3和NaHCO_3、电导率为1.89 mS·cm~(-1)、钠吸附比为10.01、碱化度为40.20%,设置了5个脱硫石膏施用水平(施用量分别为土重的0.0%,0.5%,1.0%,1.5%,2.0%),并利用Philip和Kostiakov两种入渗模型描述土壤水分入渗过程。结果表明:在入渗时间为630 min时,0.5%、1.0%、1.5%、2.0%处理累积入渗量与0.0%处理相比分别增加20.00%、43.03%、61.21%、55.15%,入渗率分别增加64.94%、233.33%、271.86%、339.83%;当湿润锋运移至60 cm时,0.5%、1.0%、1.5%、2.0%处理所用时间比0.0%处理分别减少33.33%、63.89%、63.89%、70.83%;同时,脱硫石膏显著影响了Philip和Kostiakov入渗公式参数,随脱硫石膏用量的增加而增加,吸渗率S从0.0647 cm·min~(-0.5)增加到0.0957 cm·min~(-0.5),稳定入渗率A从0.0024 cm·min~(-1)增加到0.0189 cm·min~(-1),经验指数K从0.0165增加到了0.0698;在50~60 cm土层深度随着脱硫石膏用量的增加电导率逐渐增加,土壤脱盐效率增加。综上,脱硫石膏可以加快苏打盐碱土水分入渗速率,增加脱盐效率,对苏打盐碱土改良有很好的效果。  相似文献   

4.
Murad  Zaryab  Ahmad  Ijaz  Waleed  Muhammad  Hashim  Saima  Bibi  Sobia 《Gesunde Pflanzen》2022,74(1):151-158

A pot experiment was conducted at Institute of Biotechnology and Genetic Engineering (IBGE), University of Agriculture Peshawar, Pakistan. To conduct the experiment, eight kilograms of air-dried soil were taken in each pot and the amendment biochar was added and mixed properly at different levels like 0%, 1%, 2% and 4% (w/w), respectively. All pots were spiked with Cd solution at the concentration of 10?mg kg?1. The treatments were arranged in completely randomized design (CRD). Fourteen days old nursery plants of rice Oryza sativa L. were transplanted into pots. Five rice plants were grown in each pot. After transplantation of rice plant, the nitrogenous and phosphatic fertilizers (Urea and DAP) were incorporated at the standard rate. Standing water condition was kept for rice grown in pots. Rice plants were harvested after 70 days germination. Soil samples were collected from each pot after plant harvesting. After soil analysis, the given data elaborated that the concentration of Cd in soil was stabilized by the amendment from 8.7?mg kg?1 (0%) to 4.2?mg kg?1 (4%). Among the other soil parameters the minimum soil pH (7.31), EC (0.151?dSm?1), soil organic matter (0.63%), N (0.13%), P (4.72?mg kg?1) and K (55.6?mg kg?1) were noted at 0% biochar application, while maximum pH (8.23), EC (0.231?dSm?1), soil organic matter (1.67%), N (0.25%), P (8.96?mg kg?1) and K (93?mg kg?1) were found in the pot treated with 4% biochar. Hence, it was concluded that Cd was significantly immobilized with 4% biochar application.

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5.
季方 《干旱区研究》1996,13(4):20-23
本文将塔克拉玛干沙漠土壤发条条件分为稳定,不稳定,极不稳定三类,它们对于土生状有着不同的影响。在稳定的土壤发育条件下,土壤剖面有可以鉴别的诊断层,其中一性状特征沿剖面分异明显。在不稳定土壤发育条件下,土壤的诊断层表现不突出,造成它的性状特征沿剖面分异不十分明显。  相似文献   

6.
土壤风蚀的野外风洞实验研究   总被引:3,自引:0,他引:3  
<正> 土地的不断沙漠化已给自然的生产潜力和人类的生活环境带来了巨大的危害,目前这种危害正在加速地强化着。因此作为沙漠化研究中的一个重要内容——土壤风蚀的研究就显得十分重要了。我们内蒙古林学院在国内外专家的帮助下,于1986年初,顺利地  相似文献   

7.
The influence of 1 and 50 mg active ingredient (AI) kg-1 soil of 17 fungicides on transformations of urea nitrogen in soil was studied by determining the amounts of urea hydrolysed and the amounts of nitrate and nitrite produced when samples of two coarse-textured and two fine-textured soils were incubated aerobically for various times after treatment with urea. When applied at the rate of 1 mg AI kg-1 soil, anilazine, benomyl, captan, chloranil, mancozeb and thiram retarded urea hydrolysis in the two coarse-textured soils and maneb retarded urea hydrolysis in all four of the soils used. Most of the fungicides tested retarded nitrification of urea nitrogen in the two coarse-textured soils when applied at the rate of 1 mg AI kg-1 soil, but only etridiazole markedly retarded nitrification of urea nitrogen in all of the soils used when applied at this rate. When the fungicides were applied at the rate of 50 mg AI kg-1 soil, anilazine, captan, chloranil, fenaminosulf, folpet, maneb, mancozeb and thiram retarded urea hydrolysis in the four soils studied, and all fungicides tested except chloroneb, fenarimol and iprodione retarded nitrification of urea nitrogen in these soils. One-way analysis of variance and correlation analyses indicated that the inhibitory effects of the 17 fungicides tested on nitrification of urea nitrogen in soil increased with decrease in the organic-matter content and increase in the sand content of the soil. © of SCI.  相似文献   

8.
The dependence of the behaviour of metsulfuron-methyl on soil pH was confirmed during incubations under controlled laboratory conditions with two French soils used for wheat cropping. The fate of [14C] residues from [triazine-14C]metsulfuron-methyl was studied by combining different experimen-tal conditions: soil pH (8·1 and 5·2), temperature (28 and 10°C), soil moisture (90 and 50% of soil water holding capacity) and microbial activity (sterile and non-sterile conditions). Metsulfuron-methyl degradation was mainly influenced by soil pH and temperature. The metsulfuron-methyl half-life varied from five days in the acidic soil to 69 days in the alkaline soil. Under sterile conditions, the half-life increased in alkaline soil to 139 days but was not changed in the acidic soil. Metsulfuron-methyl degradation mainly resulted in the formation of the amino-triazine. In the acidic soil, degradation was characterised by rapid hydrolysis giving two specific unidentified metabolites, not detected during incubations in the alkaline soil. Bound residues formation and metsulfuron-methyl mineralisation were highly correlated. The extent of bound residue formation increased when soil water content decreased and was maximal [48 (±4)% of the applied metsulfuron-methyl after 98 incubation days] in the acidic soil at 50% of the water holding capacity and 28°C. Otherwise, bound residues represented between 13 and 32% of the initial radioactivity. © 1998 SCI  相似文献   

9.
农牧交错带土地退化类型区的划分及其防治研究   总被引:2,自引:1,他引:1  
本文在研究阴山北麓地区环境背景的基础上 ,从自然因素、土地利用因素、社会经济因素及土地退化程度因素中选出 2 3个指标变量 ,首先运用主成分分析的数学方法 ,将该区划分为 3个不同的土地退化类型区 ,分别为半干旱农业为主区 ,半干旱牧业为主区 ,和干旱牧业为主区。其次、根据土地退化评价体系对该区退化土地进行了评价研究。最后在评价的基础上 ,将阴山北麓地区细分为 5个土地退化类型区 ,分别为干旱牧农结合中度风蚀沙化丘陵区 ,半干旱农牧结合极强度风蚀沙化丘陵区 ,半干旱农业为主强度风蚀沙化滩川平原区 ,半干旱林牧农结合中度水蚀山地 ,半干旱牧业为主强度风蚀沙化高平原区。最后对不同的土地退化类型区根据各区地形地貌特征、土地退化类型、土地退化程度、自然资源状况、生态经济条件和经济发展趋势的相似性 ,结合环境综合治理方案 ,以保持乡 (镇 )行政区划的完整性为原则将该区又划分为四个生态经济类型区 ,即丘陵防风固沙牧、林、农结合区 ,滩川地农牧结合区 ,山地水土保持林、牧结合区和高平原防风固沙牧业为主区 ,在此基础上提出了土地退化防治分区整治途径。  相似文献   

10.
土壤环境因子对毒死蜱两种剂型持效性的影响   总被引:1,自引:1,他引:0  
季静  李杨  高志山  刘峰 《农药学学报》2011,13(4):364-368
以暗黑鳃金龟Holotrichia parallela幼虫为生物试材,研究了含水量、温度和泥炭质量分数3种土壤环境因子对毒死蜱30%微囊悬浮剂(CS)和30%乳油(EC)持效性的影响。结果显示:在相同土壤介质环境下,毒死蜱乳油的持效期随土壤含水量的提高而缩短,同时土壤含水量的提高减缓了微囊悬浮剂囊内有效成分的释放;在土壤中其他影响因子相同时,土壤温度越高,毒死蜱微囊悬浮剂和乳油的持效期越短;土壤中的泥炭对毒死蜱的吸附作用使得其对暗黑鳃金龟幼虫的初始毒力降低,同时也延长了毒死蜱在土壤中的持效期。对于3种土壤环境因子的不同处理,除泥炭质量分数为1.0%的处理中毒死蜱微囊悬浮剂和乳油对暗黑鳃金龟幼虫的持效性相差不大外,其他各处理中毒死蜱微囊悬浮剂的持效性均优于乳油。  相似文献   

11.
Combined applications of cyanobacteria with soil fixing chemicals were investigated to generate artificially induced biological soil crust (BSC). Polyvinyl alcohol (PVA) and Tacki-Spray (TKS7) chemicals composed of bio-polysaccharides and tackifiers were examined under laboratory conditions. Following singular applications of chemicals, the mean weight diameter values of soil treated with TKS7 were 1.4–2.5 times higher than those of soil treated with PVA and thus TKS7 was selected for further tests for application with cyanobacteria (Nostoc Vaucher ex Bornet &; Flahault, Phormidium Kützing ex Gomont, and Scytonema arcangeli Bornet ex Flahault). Combined application of cyanobacteria and different concentrations of TKS7 enhanced soil aggregate stability, resulting in mean weight diameter values of 0.58–0.69 mm and was comparable to TKS7 singular application (0.18–0.40 mm). Surface hardness values were also highly improved by the combined application of cyanobacteria with TKS7 (4.5 MPa) compared to singular treatment of cyanobacteria (2.3 MPa). In addition, superabsorbent polymer (SAP) was applied as a water-holding material and nutrient supplement in soil. The SAP promoted cyanobacterial cell growth under dry conditions. Chlorophyll a content of soil was improved by the addition of SAP (CST1: 2.93 µg g?1) compared to singular treatment of cyanobacteria (C: 2.25 µg g?1). These results suggest that combined application of cyanobacteria with TKS7 and SAP can induce BSC formation faster than singular application of cyanobacteria. The novel method presented herein can be applied to restoration of degraded soils in arid and semiarid areas.  相似文献   

12.
Studies of wind erosion based on Geographic Information System(GIS) and Remote Sensing(RS) have not attracted sufficient attention because they are limited by natural and scientific factors.Few studies have been conducted to estimate the intensity of large-scale wind erosion in Inner Mongolia,China.In the present study,a new model based on five factors including the number of snow cover days,soil erodibility,aridity,vegetation index and wind field intensity was developed to quantitatively estimate the amount of wind erosion.The results showed that wind erosion widely existed in Inner Mongolia.It covers an area of approximately 90×104 km2,accounting for 80% of the study region.During 1985–2011,wind erosion has aggravated over the entire region of Inner Mongolia,which was indicated by enlarged zones of erosion at severe,intensive and mild levels.In Inner Mongolia,a distinct spatial differentiation of wind erosion intensity was noted.The distribution of change intensity exhibited a downward trend that decreased from severe increase in the southwest to mild decrease in the northeast of the region.Zones occupied by barren land or sparse vegetation showed the most severe erosion,followed by land occupied by open shrubbery.Grasslands would have the most dramatic potential for changes in the future because these areas showed the largest fluctuation range of change intensity.In addition,a significantly negative relation was noted between change intensity and land slope.The relation between soil type and change intensity differed with the content of Ca CO3 and the surface composition of sandy,loamy and clayey soils with particle sizes of 0–1 cm.The results have certain significance for understanding the mechanism and change process of wind erosion that has occurred during the study period.Therefore,the present study can provide a scientific basis for the prevention and treatment of wind erosion in Inner Mongolia.  相似文献   

13.
羊草和脱硫石膏对内蒙古河套地区盐渍化土壤的改良效果   总被引:2,自引:0,他引:2  
为了解脱硫石膏和耐盐植物改良与培肥盐渍化土壤的作用与效果,在内蒙古河套地区硫酸盐盐渍化土壤上设置田间试验,测定施用脱硫石膏(30 t·hm-2)与不施用脱硫石膏并种植羊草后土壤盐分及基础理化性质的变化。结果表明:春季灌溉可大幅度降低土体p H值、电导率(EC)和盐分离子浓度,施用脱硫石膏可加快降低土壤碱度,主要盐分离子Na+和SO42-分别降低了80%和39%以上,但EC略有提高,导致养分淋失;羊草对脱硫石膏有良好的反应,生物量提高了30%,但全磷含量降低了22%,全氮、全钾含量没有显著变化;种植羊草降低Na+和SO42-含量至3.38 mg·kg-1和132.27 mg·kg-1,且土壤有机质和碱解氮含量分别提高了12%和37%,同时施用脱硫石膏效果更好一些。说明脱硫石膏与羊草之间具有一定的相互作用,可加速盐渍化土壤改良的进程,但需要注意的是应适当增加施用P、K肥料,以补充养分不足。  相似文献   

14.
施用7%草甘膦水剂对土壤盐化和碱化的影响   总被引:2,自引:0,他引:2  
通过室内盆栽模拟实验,研究了5种浓度的7%草甘膦水剂对土壤盐化和碱化的影响。结果表明,施药后土壤盐度(用电导率表示)、钠碱化度(ESP)、钠吸附比(SAR)、总碱度及pH值都明显增大,且随施药次数的增加,上述各项盐化和碱化指标不断增大;每次施药后,土壤的各项盐化和碱化指标都随施药浓度的升高呈增大趋势。6次施用0.352 g/L的7%草甘膦水剂后,土壤的电导率由施药前的1 010增加为2 460 μS/cm,ESP由2.247%增加为7.983%,SAR由1.576增加为4.305,总碱度由1.443 mmol/L增加为4.485 mmol/L,pH值由6.92变为7.89。虽然土壤各项盐化和碱化指标的变化都还在非盐化和非碱化土范围内,但有盐化和碱化的趋势。  相似文献   

15.
基于毛乌素沙地的野外观测资料,对毛乌素沙地典型地形断面土壤水分动态进行分析。结果表明,土壤水分季节变化可划分为土壤水积聚期、消耗期和稳定期;根据土壤水分垂直变化可把土壤剖面划分为土壤水分易变层、利用层和调节层;沿着坡度减小的方向,各地形断面对应层次的土壤水分含量逐渐升高,丘间地土壤水分含量明显高于该断面上其余各点。  相似文献   

16.
The persistence of [14C]MCPA at a rate equivalent to 1 kg ha?1 was studied under laboratory conditions in a clay loam, heavy clay and sandy loam at 85% of field capacity moisture and 20±1°C both alone and in the presence of tri-allate, trifluralin, tri-allate and trifluralin, malathion, Vitaflow DB, malathion and Vitaflow DB, bromoxynil, bromoxynil and asulam, bromoxynil and difenzoquat, dicamba, dicamba and mecoprop, linuron, MCPB, metribuzin, propanil, TCA, benzoylprop-ethyl, diclofop-methyl, and flamprop-methyl. Except in the soils treated with asulam, the half-lives of [14C]MCPA in all three soil types were similar, being approximately 13±1 days, thus indicating that none of the other chemicals studied adversely affected the soil degradation of MCPA. In the asulam treated soils, the half-lives of the MCPA were about 3 days longer than in non-asulam treated soils; the effect was most marked in the clay loam.  相似文献   

17.
Accelerated degradation of vernolate, EPTC and butylate but not of cycloate was detected in soils from three locations in Israel which were treated annually with vernolate. Repeated application of EPTC to soils with and without a history of vernolate application, under laboratory conditions, resulted in a progressive increase in its rate of dissipation with each application. Accelerated degradation of EPTC was also rapidly induced by mixing small amounts (5%) of soil with a history of vernolate treatment with soil that had never received vernolate. Liberation of 14CO2 from [14C]EPTC was more rapid in vernolate-treated soils than in untreated soils, indicating a development of microbial populations in soil capable of rapidly degrading the EPTC. Degradation of [14C]EPTC was faster in soil previously cropped with maize than in non-cropped soil, but slower in soils cropped with cotton or peanuts.  相似文献   

18.
耕作地表土块状况及其对近地表风场的影响   总被引:5,自引:0,他引:5  
为深入理解非可蚀性土块吸收风能、降低侵蚀力的机制,利用野外风速资料,对半干旱区农田传统耕作模式下犁耕、耙耱及抹平等的地表土块大小、土壤表面粗糙度、近地表风速及空气动力学特征进行了研究。结果表明,犁耕后农田土块长、宽、高均在15 cm以上,盖度为27.67%,耙耱、抹平后土块大小和盖度显著降低,抹平地表土块盖度仅为2.13%;土块的破碎导致土壤表面粗糙度降低,近地表风速增大;与犁耕地表比较,耙耱后土壤表面粗糙度降低34%~64%,抹平后降低幅度甚至在90%以上;耙耱抹平后地表以上0.5 m高度内风速显著增大,空气动力学粗糙度由1.1 cm降低至0.05 cm,侵蚀力增强。因此认为,合理选择犁耕、耙耱和抹平的时间对农田风蚀防治有实际意义。  相似文献   

19.
This study was conducted to evaluate short- and long-term effects of poultry and sheep manures, as well as sunflower, canola, and potato residues, which commonly are being used as organic amendments (OAs) in agricultural soils, on the pH value, buffering capacity, and nitrogen (N) turnover of a sub-alkaline agricultural soil using laboratory incubation. The tested OAs had pH values ranging from alkaline (manures) to acidic (plant residues), and their effects of the short- and log-term on soil pH value were assessed by fractionation of the OAs alkalinity and evaluating the contribution of OA-borne N mineralization to soil acidity. On average, 45% of potential alkalinity in tested OAs was available for acid-base reactions, soluble alkalinity accounted for 58, 80, 32, 50, and 50% of the excess cations for poultry manure, sheep manure, sunflower, canola, and potato residues, respectively. Buffering capacity of the tested OAs was higher for sunflower residues, potato residues, and poultry manure and lower for canola residues and sheep manure. The tested OAs showed different N mineralization potential, and during the 100 days of incubation, soils amended with sheep manure, poultry manure, and potato residues released 107, 118, 129, and 240?mg?N?kg?1 soil, respectively, more than double than that released from unamended soil. Our results demonstrated that long-term impact of OAs on the soil pH value is not related to the initial OAs pH value and soluble alkalinity and that available alkalinity and N mineralization are key factors regulating the soil pH value on the long-term.  相似文献   

20.
莫索湾垦区荒漠化土地物理特性研究   总被引:6,自引:0,他引:6  
荒漠化是通过一种或多种营力过程造成的土地退化过程。本文选取莫索湾垦区风力作用和物理作用所造成的沙质荒漠化,泥质荒漠化和碱化土地为样品,通过土壤的机械组成分析,土壤饱和含水率,容重和田间持水量,以及入渗率的测试,定量地研究了土壤在荒漠化过程中物理性质的变化。  相似文献   

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