Air pollution injury to coastal sage scrub in the Santa Monica Mountains,Southern California

Water, Air, & Soil Pollution - Tomato (Lycopersicon esculentum Mill.) plants, cultivar Fireball, were grown with 1.6, 16 or 80 ppm (mg L−1) sulphate- S in nutrient solution added daily to...     

古尔班通古特沙漠土壤化学性质空间异质性的尺度特征

从根际(10-3m~10-2m)、个体(10-1m~100m)、种群(100m~101m)、地貌(101m~102m)和区域(103m~104m)五个作用因子所在的尺度对古尔班通古特沙漠土壤的pH、电导率、有机质、全氮、速效氮、全磷和速效磷的空间异质性进行了研究,结果表明,土壤pH在各尺度异质性的大小顺序为:个体>种群>地貌>区域>根际,说明引起土壤pH变化的主要因子是植物个体和种群,而地貌状况、气候及水文对于土壤pH的影响不大,根际对土壤pH的影响最小。土壤电导率在各尺度异质性的大小顺序为:个体>区域>种群>地貌>根际,说明植物个体对于改变土壤盐分含量起主导作用,地貌状况和根际对土壤盐分状况的影响很小。土壤有机质、全氮、速效氮和速效磷的空间异质性均在个体尺度上最大,地貌尺度上次之,而种群尺度上最小,说明植物个体对于土壤养分的空间异质性起主导作用,地貌对这些养分的异质性作用也是不容忽视的,而植物种群对土壤养分的异质性最小。土壤全磷的异质性则在地貌尺度最大,个体尺度次之,根际尺度最小,说明地貌特征是影响土壤全磷含量的主要因子,其次是植物个体,而根际对于土壤全磷的影响很小。     

Effects of tanneries wastewater on chemical and biological soil characteristics

Effluents from leather processing, a major industry that produces up to 64320 t wastewater year⁻¹ in the town of León (Guanajuato, Mexico), are normally discharged to the river Turbio without treatment. This water is downstream used to irrigate agricultural land. Tannery wastewater contains valuable nutrients, but also contaminants, such as salts and chromium (Cr), that might affect soil processes and crop production. We investigated how almost 25 years of irrigation of agricultural land with water from the river Turbio affected soil characteristics, dynamics of carbon (C) and nitrogen (N), and microbial biomass C. Soil sampled from three adjacent fields irrigated with tannery effluent (soil A), in the vicinity irrigated with well water (soil B), and at a distance of 10 km from the irrigation canals (soil C), was characterized while dynamics of C and N were measured in an aerobic incubation experiment. Irrigation with water from the river Turbio for over 25 years had significantly increased the electrolytic conductivity from 0.64 to 2.29 dS m⁻¹, organic C and total N content two-times, total concentration of Cr four-times, copper (Cu) two-times and sodium (Na) six-times in the clayey soils (P < 0.05). Microbial biomass was two-times larger in soil A than in soil C, while the activity of proteases and hydrolases releasing ninhydrin positive compounds and organic C appeared not to be affected. The concentrations of ammonium (NH₄⁺) and nitrate (NO₃⁻) were not significantly different between the soils. The concentration of nitrite (NO₂⁻) was approximately twice larger in soil A than in soil C (P < 0.05). Although there appeared to be no adverse impact on soil characteristics and microbial biomass, oxidation of NO₂⁻ was inhibited indicating that the biological functioning of the soil might be affected. The increase in heavy metals in soil was limited, but continued irrigation with water from the river Turbio might increase sodicity and salinity that could deteriorate soil and pose a threat to future crop production.     

Decomposition in soil and chemical characteristics of pollen

The input to soils made by pollen and its subsequent mineralization has rarely been investigated from a soil microbiological point of view even though the small but significant quantities of C and N in pollen may make an important contribution to nutrient cycling. The relative resistance to decomposition of pollen exines (outer layers) has led to much of the focus of pollen in soil being on its preservation for archaeological and palaeo‐ecological purposes. We have examined aspects of the chemical composition and decomposition of pollen from birch (Betula alba) and maize (Zea mays) in soil. The relatively large N contents, small C‐to‐N ratios and large water‐soluble contents of pollen from both species indicated that they would be readily mineralized in soil. When added to soil and incubated at 16°C an amount of C equivalent to 22–26% of the added pollen C was lost as CO₂ within 22 days, with the Z. mays pollen decomposing faster. For B. alba pollen, the water‐soluble fraction decomposed faster than the whole pollen and the insoluble fraction decomposed more slowly over 22 days. By contrast, there were no significant differences in the decomposition rates of the different fractions from Z. mays pollen. Solid‐state ¹³C nuclear magnetic resonance (NMR) revealed no gross chemical differences between the pollen of these two species, with strong resonances in the alkyl‐ and methyl‐C region (0–45 p.p.m.) indicative of aliphatic compounds, the O‐alkyl‐C (60–90 p.p.m.) and the acetal‐ and ketal‐C region (90–110 p.p.m.) indicative of polysaccharides, and the carbonyl‐C region indicative of peptides and carboxylic acids. In addition, both pollens gave a small but distinct resonance at 55 p.p.m. attributed to N‐alkyl‐C. The resonances attributed to polysaccharides were lost completely or substantially reduced after decomposition.     

长期单施化肥和有机无机配合条件下红壤蔗区土壤生物学性状及细菌多样性差异

【目的】分析红壤区长期施肥的蔗区土壤生物学性状和细菌多样性,旨在提出提升红壤蔗区土壤肥力与健康的施肥方案。【方法】试验从1995年开始,于广西来宾市蒙村镇那洪村甘蔗长期试验站进行。试验设置不施肥(CK)、 长期单一施用化肥(NPK)和长期化肥配施有机肥(NPKM)3个处理。采用聚合酶链式反应-变性梯度凝胶电泳(PCR-DGGE)以及稀释平板法等传统和现代分析技术,比较分析了3种长期不同施肥处理对蔗区土壤生物学指标、 细菌多样性等指示土壤肥力与健康状况指标的影响。【结果】施肥处理导致甘蔗产区土壤pH下降,NPK处理下降幅度大于NPKM处理。土壤中可培养微生物数量(细菌、 真菌和放线菌)均以NPKM处理为最高,NPK处理真菌数量显著高于CK,放线菌数量却显著低于CK土壤,细菌数量两者间无显著差异。微生物量碳、 氮以及涉及碳、 氮、 磷循环的土壤酶活性均以NPKM处理土壤为最高,与NPK和CK土壤差异显著。NPK处理土壤中β-葡糖苷酶活性以及微生物量碳高于CK土壤,但蛋白酶、 磷酸酶活性以及微生物量氮显著低于CK土壤。NPKM处理土壤中细菌多样性指数(H)、 丰富度(S)以及均匀度(EH)指数等同样表征土壤肥力与质量的敏感指标均高于NPK和CK土壤。【结论】长期施肥可不同程度地导致红壤蔗区土壤pH下降,长期单一施用化肥处理下降幅度高于化肥与有机肥配施处理。长期单一施用化肥加剧了土壤肥力下降与质量劣化,化肥配施有机肥是减缓红壤甘蔗产区土壤pH下降、 提升土壤肥力和保持土壤健康的有效措施。     

苏北海涂围垦区表层土壤体积质量的空间异质性研究

针对不当开发利用导致滩涂土壤理化性质恶化的现实状况,以苏北海涂围垦区为研究区域,应用地统计学方法研究了表土层体积质量这一物理性质的空间异质性.结果表明:研究区表层土壤表现出紧实趋势,各植被类型下表土层体积质量均为弱变异强度;表土层体积质量的分布总体表现为各向同性,较好地符合指数模型;受结构性因素与随机性因素共同作用,表土层体积质量表现为中等空间相关性.Moran's I系数分析表明,表土层体积质量呈较弱的相关关系,随机性因素是引起其空间异质性的关键原因.水稻种植区表土层体积质量要明显高于棉花种植区,其空间分布格局不仅与土地利用方式差异密切相关,土壤质地差异也是较为重要的因素.该研究为海涂围垦区中、低产地及障碍土壤的合理利用与科学管理提供一定的参考依据.     

Predicting soil water retention characteristics from soil physical and chemical properties

Abstract

Knowledge of soil water availability for plant growth is vital for the development of plant growth simulation models. Data on soil water availability are often not available because field and laboratory measurements of soil water content are time‐consuming and tedious. The objective of this study was to develop alternative procedures to predict water content at ‐10 kPa (UL10), ‐33 kPa (U133), ‐1500 kPa (LL), and the potential available water capacity (AWC) from easily and routinely available soil properties. Multiple regression equations for soil orders of Soil Taxonomy were developed using a database containing information of about 12,000 pedons of the continental U.S., Hawaii, Puerto Rico, and some foreign countries. Regression equations with bulk density, sand, silt, clay, and organic carbon contents accounted for up to 83% of the variation in UL10 for all orders except Ultisols. For Ultisols, sand content accounted for up to 90% of the variation in UL10. Equations with clay and organic carbon contents accounted for up to 75% of the variability in UL33 for all except Aridisols, Oxisols, Vertisols, and Spodosols. For these four orders, equations with bulk density, clay, silt, and sand contents accounted for up to 81% of the variation in UL33. LL was linearly related to clay content. Clay content accounted for up to 91% of the variation in LL for all but Oxisols and Vertisols. More accurate predictions of AWC resulted when AWC was computed from UL10 and LL water content data. Equations with bulk density alone or bulk density plus silt and/or sand contents accounted for up to 83% of the variation in AWC for all except Entisols, Inceptisols, and Spodosols.     

不同改良剂对滨海盐渍土土壤理化性质和小麦生长的影响

【目的】盐分胁迫是滨海盐渍土上粮食产量提高的主要障碍因子之一。研究不同功能性改良物料对消除和减轻这一障碍因子的作用,为改良盐渍化土壤和提高作物产量提供理论依据。【方法】以小麦品种‘青麦 6 号’为供试材料,在滨海盐渍土上进行田间试验,设置 7 个处理为空白对照（CK）、含钙物料的磷石膏（PG）和脱硫石膏（FGD）、调酸物料的硫酸亚铁（FS）、含碳材料的牛粪（M）以及含碳和调酸物料的腐植酸（HA）和糠醛渣（FRs）,分析比较不同改良剂对滨海盐渍化土壤理化性质以及对小麦生长发育的影响。【结果】施加改良剂降低了土壤表层 (0—20 cm) 的 pH 值,作为酸性材料的腐植酸、糠醛渣和硫酸亚铁效果明显,土壤的 pH 值较对照分别降低了 0.10、0.11 和 0.11;施改良剂降低了土壤的交换性钠离子含量和钠的吸附比 (sodium adsorption ratio, 简称 SAR),磷石膏和脱硫石膏提供充足的钙离子用于置换土壤中交换性钠离子,明显降低了不同土层中的交换性钠离子含量和 SAR 值,0—20 cm、20—40 cm 和 40—60 cm 土层中,磷石膏和脱硫石膏对土壤交换性钠离子含量和 SAR 值的降低效果明显,其中施加磷石膏分别较对照降低了 15.5% 和 18.3% (0—20 cm)、28.2% 和 28.6% (20—40 cm)、36.5% 和 36.5% (40—60 cm),施加脱硫石膏分别较对照降低了 24.9% 和 27.9% (0—20 cm)、27.6% 和 26.3% (20—40 cm)、24.5% 和 25.0% (40—60 cm);施加改良剂增加了小麦成熟期的穗数,其中磷石膏、脱硫石膏和糠醛渣改良效果显著,分别较对照增加 27.6%、24.5% 和 18.6%,并分别提高小麦的产量 26.7%、17.8% 和 17.8%。【结论】 酸性物料的糠醛渣、腐植酸和硫酸亚铁,可以明显降低土壤 pH 值和增加小麦苗期的茎蘖数量,综合考虑改良剂对土壤 pH、Na+ 含量、SAR 值和小麦群体数量的影响,含碳的调酸物料的糠醛渣效果较好;含钙物料的磷石膏和脱硫石膏,可以显著降低土壤 Na+ 含量以及 SAR 值,增加小麦成熟期穗数,提高小麦产量均具有显著的效果,磷石膏效果最佳。     

河北省滨海盐碱地土壤与盐生植物养分特征的研究

对滨海盐碱地土壤和植物样品分析结果表明,生长不同盐生植物的土壤含盐量不同,以生长白刺(Nitraria sibirica Pall.)的土壤含盐量最高,达18.5 g/kg,盐地碱蓬(Suaeda salsa L.Pall.)次之,柽柳的最低。盐生植物的生长改变了土壤养分特征,4种生长盐生植物的土壤养分含量均高于光板地,土壤有机质含量增加44％以上,生长木本盐生植物白刺、柽柳(Tamarix chinensis Lour.)的土壤养分含量高于生长草本盐生植物碱蓬、碱茅(Puccinellia distans Jacq.Parl.)的土壤,且不同盐生植物养分特征不同,白刺、柽柳N和P含量均高于盐地碱蓬、碱茅,K含量则与植物耐盐特性有关。     

盐渍化土壤光谱特征的区域异质性及盐分反演

该文通过分析中国新疆、浙江、吉林3个不同地区盐渍化土壤的高光谱特征,研究了盐渍化土壤高光谱特征的区域异质性,并对构建高精度的跨区域土壤盐分高光谱定量反演模型,应用25种数据处理方式来提高全局建模的精度,旨在提高具有光谱异质性土壤的盐分反演精度。结果表明:不同地区的盐渍化土壤,无论是反射率还是光谱曲线形态方面,均存在较明显的差异,但经过一阶微分处理后,光谱差异有所降低;对3个地区土壤盐分含量局部建模与全局建模的精度进行比较,在所选用的直线回归、主成分回归、多元线性回归、偏最小二乘回归4种建模方法中,全局建模精度均低于局部建模精度;不同地区盐渍化土壤的盐分敏感波段不一致,在所采用的25种数据处理方式中,SG3点一阶微分(savitzky golay)、SG5点一阶微分、SG7点一阶微分、线性基线校正+SG3点一阶微分、SG平滑+SG3点一阶微分、SG平滑+线性基线校正+SG3点一阶微分这6种数据处理方式对全局建模的建模精度有明显改善作用,模型的相对分析误差均达到2.0以上,其中以SG平滑+SG3点一阶微分为最佳,其决定系数、均方根误差、相对分析误差分别为0.80、0.43、2.23。研究结果为跨区域土壤盐渍化的航天高光谱遥感监测提供了一定的参考依据。     

改良剂施用对重金属污染土壤溶液化学性质及豇豆生理特性的影响研究

本文研究了在不同生长时期凹凸棒土、硅藻土、泥炭、腐植酸对土壤重金属的钝化及豇豆生理特性的影响。结果表明:由于土壤的缓冲性,4种改良剂对土壤溶液pH影响较小;泥炭、腐植酸对Zn、Cu的钝化效果比凹凸棒土、硅藻土好,但4种改良剂对土壤溶液Pb和Cd浓度影响不明显;腐植酸、凹凸棒土均在不同程度上提高了豇豆叶片超氧化物歧化酶、过氧化物酶的活性,其中腐植酸的作用最为明显。除泥炭外,3种改良剂均使豇豆叶片的丙二醛、脯氨酸含量降低。受叶片衰老的影响,成熟期各改良剂对豇豆生理特性的作用不如苗期明显;冗余分析表明:4种改良剂对重金属的钝化效果依次为腐植酸、泥炭、凹凸棒土、硅藻土。本次试验结果说明有机物料腐植酸、泥炭可作为缓解豇豆重金属Zn、Cu胁迫的改良剂。     

天津滨海盐渍土客土改良后的土壤理化性质与持水特性

为了解天津滨海新区盐渍土采用客土法改良后的土壤理化性质的变化情况,该研究选取滨海新区汉沽区的滨海盐渍土以及采用客土改良后历经5 a的土壤(配制客土)作为研究对象,测定分析这2种土壤0~60 cm不同土层土样的基本理化性质、土壤水分特征曲线,探讨了理化性质和土壤水分参数的差异。结果表明:客土改良后历经5 a的配制客土电导率远低于未改良的滨海盐渍土,降幅约为97%,有效含水量以及田间持水量明显低于滨海盐渍土。有机质质量分数和阳离子交换量分别增加了29.65%和8.36%,pH值和容重变化不大。综合分析后认为,滨海盐渍土经配制的客土改良后,盐渍化程度减弱,有机质增大,但持水特性和物理性质却没有明显的改善。土壤质地黏重是影响该地区土地资源开发利用的主要因素之一。     

滨海盐碱地人工刺槐白蜡混交林的根际土壤特性研究

以黄河三角洲人工刺槐白蜡混交林为对象,在调查林分长期生长特征的基础上,以林地非根际土为对照,研究了刺槐和白蜡根际土的理化性质、酶活性和微生物数量等土壤特性。结果表明,刺槐和白蜡根际土壤pH值较林地非根际土显著降低,白蜡根际土壤中的盐分出现明显的富集现象。刺槐根际土壤中碱解氮含量虽然高于白蜡,但白蜡根际土有机质、有效磷和速效钾含量均明显高于刺槐,总体肥力较高。除脲酶活性外,白蜡根际土的过氧化氢酶、转化酶、多酚氧化酶活性明显高于刺槐。刺槐和白蜡的根际土壤微生物数量均大于非根际土壤,三者的大小顺序为:白蜡根际土>刺槐根际土>非根际土。综合研究结果表明,白蜡根际土壤质量总体上明显优于刺槐根际土,这可能是白蜡在滨海盐碱地上生长状况相对较好的重要原因。     

Relationships between biological and physico-chemical soil characteristics in a mediterranean agricultural area

Fourteen agricultural soils from various areas of Tuscany were characterized by a range of measurements indicative of soil biological activity. The objective of our research was to identify soil parameters suitable as indicators for evaluating their quality. In general, enzyme activities were found to vary widely, with the highest activity for each enzyme being distributed among only five of the 14 soils studied. The narrowest range (14-fold) in enzyme activities for the various soils was observed for catalase and the widest range (577-fold) for g -glucosidase. Biomass C and, among the measured enzyme activities, amylase, were well correlated with total organic carbon, total N, cation and anion exchange capacity. Positive correlations were found between the maximum water holding capacity and dehydrogenase, amylase, biomass C, FDA hydrolytic activity, the biological index of fertility and the enzyme activity number, so showing that soil moisture may play an important role in affecting soil biological characteristics. No significant correlations were observed among the soil enzymes themselves. The FDA hydrolytic activity appeared to be the index most related with the other biological characteristics tested in this study and, for this reason, can be considered the most effective index for putting in evidence relationships existing between the different biological characteristics in the soils investigated.     

Influence of chemical characteristics in the development of soil colour

Factors responsible for the development of colour in reddish-brown basaltic soils of Malwa Plateau, India, were studied with the aid of multiple regression correlation analysis between the soil Munsell colour parameters and the chemical characteristics. Titanium and ferrous iron for soil “hue”, clay and organic matter for soil “value” were found to influence the development of colour in these soils. Partial regression analysis was carried out to assess the relative importance of individual factors in soil colour.     

不同栽培方式对菜地土壤养分和生物学特性的影响

通过田间小区试验,以芹菜、西兰花、生菜和胡萝卜为供试作物,分析比较了有机栽培、安全环境质量栽培、特别栽培和常规栽培对土壤养分和生物学特性的影响.结果表明,有机栽培、安全环境质量栽培和特别栽培下土壤有机质、全氮、碱解氮、速效磷和速效钾含量比常规栽培均不同程度地增加.有机栽培、安全环境质量栽培和特别栽培均显著提高了土壤微生物量碳含量,比常规栽培分别提高48.6％、42.9％和26.6％,并达到显著(P＜0.05)或极显著(P＜0.01)差异.土壤过氧化氢酶和脲酶活性在有机栽培、安全环境质量栽培和特别栽培下比常规栽培显著提高17.4％ ～38.8％,且过氧化氢酶活性达到显著(P＜0.05)或极显著(P＜0.01)差异.有机栽培、安全环境质量栽培下土壤转化酶活性比常规栽培有所提高,但是没有达到显著差异.不同栽培方式对土壤养分和生物学特性影响作用的大小为有机栽培＞安全环境质量栽培＞特别栽培＞常规栽培.     

土壤调理剂对土壤理化性质及甘蓝生理特性的影响

试验研究了土壤调理剂对土壤结构性质和甘蓝根系活力、光合指标的影响.结果表明,施用调理剂后,处理两次、处理一次分别使20 cm和30 cm土层的容重下降7.3%、1.9%和4.6%、1.3%,孔隙度分别提高9.3%、2.8%和5.9%、1.9%;与对照相比,处理两次后的阳离子交换量在0～27 cm、27～45 cm土层分别增加5.7%和10.9%;甘蓝的根系活力,处理与对照相比达到1%的显著差异水平;改变了Pn的光合日变化曲线,提高了甘蓝对光强的适应能力,光合能力加强.     

磷石膏改良剂对江苏如东滨海盐土理化性状及小麦生长的影响

江苏沿海地区有大量的滨海盐土,植物难以生长,如能改良,是一种重要的农业资源。本文以如东滩涂滨海盐土为研究对象,采用室内盆栽试验,研究施用磷石膏改良剂对滨海盐土的改良效果。结果表明：磷石膏改良剂能有效的促进小麦的生长,改良剂5的小麦株高比对照2增加47.4%和68.3%,生物量分别增加66.7%和74.4%;随着磷石膏改良剂的用量增加,土壤的养分含量逐渐提高,特别是速效磷,改良剂5比对照1分别增加245.8%和463.4%;土壤盐分由原来的有害氯化钠盐占主导转变为对植物无害的硫酸盐,优化了土壤盐分组合;同时土壤的PH下降,与对照1比,下降幅度分别为7.4%和13.7%,且PH值与磷石膏改良剂的用量呈负相关,说明磷石膏对滨海盐土有很好的改良效果。     

Effect of cropping system on production and chemical and biological properties of soil

A field study was carried out at the Indian Agricultural Research Institute, New Delhi, India, for three crop years (2000–2001 to 2003–2004) to find out the effect of cropping systems on the production and chemical and biological properties of soil. Rice-potato-mungbean cropping system gave 59–89% higher productivity, 30–46% higher protein yield, 18–38% higher energy output and resulted in 7–16% higher available P, 60% higher fungi population, 15% higher actinomycetes population, 14% higher microbial biomass and 3% higher CO₂ evolution in soil than rice-wheat cropping system. Rice-rapeseed-mungbean cropping system also gave 12–15% higher productivity, 19–26% higher protein yield and resulted in 11–18% higher available P, 65% higher fungi population, 22% higher actinomycetes population, 12% higher microbial biomass and 2% higher CO₂ evolution in soil than rice-wheat cropping system. However, the rice-potato-mungbean cropping system was significantly superior to the rice-rapeseed-mungbean cropping system in productivity, protein yield and energy output and thus recommended as in alternative to rice-wheat cropping system.     

Soil salts reduce hydration of polymeric gels and affect moisture characteristics of soil

Abstract

Hydration of a hydrophilic crosslinked polystyrene (gel) in deionized water at 65 g of gel per g of soil was studied. Four different soil types were selected, three were light‐textured soils (loamy sand and sandy clay loam) and the other a clay. Container capacity, field capacity, permanent wilting point, and available water for these soils were measured for gel contents equal to 0,0.1, 0.2, and 0.3%. Absorption capacity of the gels when incorporated into the soil decreased considerably compared to its absorption in pure water. This was attributed to the increased ionic strength of soil moisture and the formation of additional ionic crosslinks in the gel network due to the presence of multivalent ions in the soils. It was found also that container capacity, field capacity, and available water capacity increased with the gel content in soil, whereas the permanent wilting point was not significantly affected.