中国东北地区盐渍土的生态分区

本文立足于盐渍土资源的合理开发利用,对地区内盐渍土进行生态分区：Ⅰ．苏打盐渍区,下分三江平原、松嫩平原、呼伦贝尔高平原,西辽河沙丘平原和辽河冲积平原等五个生态片;Ⅱ．氯化物盐渍区,下分一个滨海生态片．重点讨论了各生态片土壤的改良措施和利用途径．     

中国盐渍土研究：历程、现状与展望

盐渍土研究是以盐渍土和盐渍生境作为主要研究对象，以盐渍土和盐渍化的发生与演变过程、环境要素和人类活动对盐渍化的影响与作用机制、盐渍土的治理、改良和利用的理论与技术为主体的研究领域。我国盐渍土面积巨大、种类繁多，盐渍化问题突出，对农业生产和生态环境造成不同程度的影响。我国科学家提出的盐渍土“水盐调控”“水盐平衡”，“淡化肥沃层”和“障碍消减”等理论与技术方法，为发展农业生产、提高土地产能、保障粮食安全、拓展耕地资源等发挥了积极作用。近期我国在土壤盐渍化演变过程的监测与多源数据融合、土壤水盐运移过程模拟与尺度转换、盐渍农田养分循环与减损增效、盐渍障碍的生态消减、盐渍障碍微生物修复、盐渍农田灌排优化管理与边际水安全利用等方面取得了积极的进展和成果。建议今后深入开展盐渍土精准控盐的高效和安全用水、土壤盐渍障碍的绿色消减与健康保育、盐渍农田养分库容扩增与增碳减排、土壤盐渍化与区域生态的耦合响应和协同适应等方面的理论与技术研究。应面向农业、资源、生态、环境等领域和行业，致力于拓展理论和新技术的研究，为国家农业升级、粮食安全、耕地保护、生态安全、高质量发展发挥重要作用。本文回顾了我国盐渍土研究工作的...     

关于土壤盐渍化问题的研究趋势

文章在介绍第14届国际土壤学大会有关盐渍土壤研究的论文和讨论会概况的基础上,提出了今后的研究重点,即利用新技术研究盐渍土;寻求改良盐渍土的新方法和将盐渍土的研究与农业生态和环境保护的研究相结合。     

治理江苏沿海盐渍土的水利措施

本文简要分析了江苏沿海地区盐渍土的成因；探讨了该区土壤水盐运动规律和盐渍土改良机理；通过大量试验提出了治理盐渍土的措施、效果及有关计算方法，可作为各地改良盐渍土的参考和借鉴。     

前言

包括土壤盐渍化在内的土地荒漠化，是困扰当今世界的严重资源环境问题，特别是在随着工农业生产发展对土地（土壤）需求越来越大的情况下，更加要求人们不断地深化关于防治土壤盐渍化的科学研究。近年来，我国学者结合生产实际，进行了大量的盐渍土资源利用及区域持续发展的研究，成果丰硕，效益显著，指导了当地生产的发展。 旨在交流科研成果，进一步推动土壤管理的学科发展，合理利用盐渍土资源，提高土壤肥力，改善生态环境，促进持续发展，在中国土壤学会盐渍土专业委员会的直接领导下，由中国科学院沈阳应用生态研究所、沈阳农业大学与辽宁省土壤学会负责筹备了中国土壤学会盐渍土专业委员会新世纪第一次学术研讨会，同时编辑出版了《盐渍土资源利用与区域持续发展》论文专辑。该文集共收录论文47篇，涉及领域包括盐渍土分类与特性、盐渍土形成与积盐机制、盐渍土改良与开发利用评述等诸多方面，比较全面地反映了近期我国盐渍土科技人员在从事其研究、教学与应用开发工作的概况和最新进展。 在征集论文期间，得到了我国广大盐渍土科技工作者的积极响应，踊跃撰稿，交流经验，许多土壤学界的前辈科学家尚给予了热情鼓励。在文集的编辑过程中，尤其得到了《土壤通报》编辑部的大力支持，中国科学院沈阳应用生态研究所石元亮研究员和王春裕研究员、沈阳农业大学须湘成教授及张玉龙教授作了大量的编审工作。此外，尚获得了本届盐渍土专业委员会主任委员、副主任委员及中科院沈阳应用生态研究所、中科院南京土壤研究所、沈阳农业大学等单位的赞助。谨此，一并表示衷心的感谢。 鉴于时间仓促，水平有限，疏漏之处难免，恳请读者指正。 中国土壤学会盐渍土专业委员会 二零零一年六月沈阳     

对盐渍土资源开发利用的思考

本文叙述了我国盐渍土分布区生态环境的特点与盐渍土形成规律．介绍了我国盐渍土改良的成功经验．以水利工程技术和农业生物技术相结合的综合措　施．列举了各地根据各自具体的环境条件，进行盐渍土综合治理后，取得明显效果的典型例　子．并提出了今后应该优先考虑开发利用盐渍土种植耐盐和盐生植被，提供畜产品、优质油　料和中药材等．     

咸水结冰灌溉融水淋盐改良盐渍土研究进展

全球气候变化和人类经济社会发展使水资源、土壤资源等环境要素的合理、可持续利用成为热点,咸水结冰灌溉融水淋盐是一种新兴的改良盐渍土技术。研究证明,利用咸水结冰时咸淡分离的原理,对盐渍土进行洗盐及压盐,具有较好的改良效果和实际应用价值,同时也能起到平抑地温,减少土层水分蒸发,降低盐渍土区地下水位,改善土壤物理性质和节约灌溉用水等作用。本文系统阐述了咸水灌溉结冰洗盐的原理及意义,总结了目前关于咸水结冰灌溉的主要研究方向、试验方法和研究范围。通过分析灌溉水溶液电解质浓度在改良盐渍土方面的作用,阐述了提高电解质浓度与咸水结冰灌溉相结合的意义,并对未来咸水结冰灌溉改良盐渍土的研究重点和方向进行了讨论和展望。     

序

恩格斯早在二个世纪以前就在其名著《自然辩证法》(人民出版社，1957)中指出：“可是我们不要过早得意于我们对自然界的胜利。对于我们的每一次胜利，自然界都报复了我们。”实则人类活动能严重地影响其自身赖以生存的自然环境，甚至能从根本上动摇地球上的生命支持系统，进而威胁人类的自身生存。作为人类在地球陆地生物圈环境中从事生产与生活所绝对必要的与不可替代的空间基地抑或最基本的生产资料——土地(土壤)资源，在其开发利用的过程中就具有这种性质。土壤盐渍化特别是由人类活动所引起的土壤次生盐渍化现象，已是当今世界严重的生态问题，成为制约社会经济发展的重要因素。在我国，随着工农业生产的发展，对土地(土壤)的需求量越来越大，合理地开发利用盐渍土资源已成为经济发展的重要课题。长期以来，人们对盐渍化土壤治理的认识不断深化，措施更加得力，效果更为显著。 中国土壤学会盐渍土专业委员会旨在交流盐渍土的资源分布、发生分类、理化性质及其改良利用途径，特别是其有关的节水农业、生态农业、综合配套技术及耐盐植物开发利用等诸多方面的研究成果，征集论文，召开会议，汇编成册，反映着我国晚近年来盐渍土研究的最新进展，势将推动相关的农业生产领域及其科学研究工作。 回顾50余年来，在我国的生产实践上，纵观其盐渍土的综合治理，效果卓著。江苏省盐城新洋农业试验站实施的“水、肥、林、种、管”综合改良滨海盐渍土，辽宁省盘锦地区灌排综合种稻改良滨海盐渍土，河南省封丘县盛水源村井灌代排综合防治土壤次生盐渍化及水驿村放淤种稻改良洼涝盐碱地，山东省禹城试区井灌沟排引黄补源综合治理旱涝及盐碱，山东省陵县试区提灌提排综合治理洼涝盐碱地，河北省南皮试区井灌沟排、抽咸补淡、咸淡混浇综合治理盐碱地，河北省曲周张庄深沟浅井综合治理盐碱地，吉林省前郭灌区水肥结合种稻改良苏打盐渍土，以及新疆巴音郭楞蒙古族自治区农垦22团渠、沟、井结合改良利用盐渍土以及其它地区等等的模式或经验，已经作出了良好的示范，粮食产量大幅度上升，人民生活显著改善，不少科技工作者荣获国家嘉奖，还赢得了国际学术界同行的高度赞誉。 归结来看，在我国长期而大规模的盐渍土改良的实践中，总结出的两条最重要的经验是，其一采取边生产边改良的开发路线，其二采用水、肥相结合的综合改良措施。确认水能排盐，而肥指有机质能改土，巩固排盐效果，减轻土壤返盐，防止次生盐渍化。在国际上，我国土壤次生盐渍化的程度属最轻，实乃是这种综合措施发挥了作用，并已成为我国盐渍土改良的特征。在科研工作中，如能突出上述特征并发展成为赋有中国特色的科研成果，必将为进一步发展土壤科学和实施可持续农业而作出更大的贡献。 还须提及的，鉴于土壤盐渍化受制于区域自然地理条件和人类活动的强烈影响，通常呈现为很大的变异性和反复性，包括时间上的动态性和空间上的相互关联性，以致决定着盐渍土的改良与治理势必是经常性的和综合性的，相应地要求体现出资源的合理配置和正确处理经济发展同人口、资源、环境之间的相互关系。由此可见，盐渍土的治理尚有赖于纳入土地利用的总体规划和国土开发整治规划，成为国民经济和社会发展的重要组成部分。 陈恩凤 2001.4     

论盐渍土之种稻生态改良

在土壤盐渍化已成为破坏地球陆地生物圈的一种机制方式的不利条件下 ,通过长期研究与生产实践表明 ,以水为首要的土壤改良基础物质及肥 (有机质 )为第二类土壤改良基础物质的盐渍土种稻改良 ,已经成为行之有效的盐渍土生态综合改良的技术与途径。     

快速修复苏打草甸碱土植被对土壤盐分和酶活性的影响

苏打草甸碱土是松嫩平原西部盐渍土壤类型之一，碱化度大，pH达10以上，形成了寸草不生的光碱斑，造成了草场退化和生态环境的恶化。通过采用碱斑堆肥、覆盖等措施对盐渍土植被重建试验，能使光碱斑当年得到修复，覆盖率达到90％以上，pH下降到8．5以下。为进一步阐明改良效果，本文将对草甸碱土改良后的盐分变化及土壤酶活性进行探讨。由于土壤酶参与土壤各种生物化学反应过程，     

中国渤海海岸盐碱土及非盐碱土中土壤生物多样性

A plethora of information is available on the effects of salinity on plant growth and soil physico-chemical properties,but the effects on soil organisms are often neglected.Thus,a systematic investigation of how soil biodiversity,including bacteria,nematodes,mites,and earthworms,changes along saline gradients was conducted along the Bohai Sea coast at Laizhou City,Shandong Province,China,with 30 soil samples randomly selected and classified by salinity into two categories:saline and non-saline.Testing revealed a significantly higher abundance of the surveyed organisms in non-saline soils.The redundancy analysis showed that a negative correlation was observed between electrical conductivity and soil organism abundance in saline soil,but not in non-saline soil.Soil organic matter,available nitrogen,and total nitrogen all positively affected organism abundance in both saline and non-saline soils.The richness and Shannon diversity of nematodes were significantly higher in non-saline soils,but were not significantly different between soil types for other organisms.None of the environmental factors surveyed was obviously related to soil organism diversity.Consequently,our results suggested that soil electrical conductivity only negatively affected soil organisms in saline soil,while soil fertility positively affected soil organisms in both saline and non-saline soils.     

我国盐渍化土壤的营养与施肥效应研究进展

阐述了盐渍化土壤的营养障碍因素及其对作物、蔬菜、林木等的危害程度、盐渍化土壤中N、P、K以及微量元素的养分状况与土壤盐分效应、施肥效应和施肥技术等；重点探讨了磷石膏作为化学改良剂应用于盐渍化土壤的前景及存在的问题；简介了北方盐渍化土壤的K素发展趋势及K肥效应，并展望了今后研究的方向。     

Effect of soil salinity and sodicity on Matricaria chamomilla,L. Growth

Abstract

Growth response of Matricaria chamomilla, L. was investigated on a range of soil salinity and sodicity levels using fine and coarse‐textured soil types. Twenty treatments including 4 levels of salinity and 4 levels of sodicity on each soil type were examined in addition to control. On the coarse‐textured soils, chamomile responded best under relatively low saline and sodic conditions. Plant growth decreased with increase in salinity and sodicity. On the fine‐textured soils, plants endured saline conditions up to 13 ECe and grew better under sodic conditions. The best growth of plants was achieved on fine‐textured soils with sodicity level of 31.8 Esp.     

Response of microbial activity and biomass to increasing salinity depends on the final salinity,not the original salinity

Salinization is a global land degradation issue which inhibits microbial activity and plant growth. The effect of salinity on microbial activity and biomass has been studied extensively, but little is known about the response of microbes from different soils to increasing salinity although soil salinity may fluctuate in the field, for example, depending on the quality of the irrigation water or seasonally. An incubation experiment with five soils (one non-saline, four saline with electrical conductivity (EC_e) ranging from 1 to 50 dS m⁻¹) was conducted in which the EC was increased to 37 EC_e levels (from 3 to 119 dS m⁻¹) by adding NaCl. After amendment with 2% (w/w) pea straw to provide a nutrient source, the soils were incubated at optimal water content for 15 days, microbial respiration was measured continuously and chloroform-labile C was determined every three days. Both cumulative respiration and microbial biomass (indicated by chloroform-labile C) were negatively correlated with EC. Irrespective of the original soil EC, cumulative respiration at a given adjusted EC was similar. Thus, microorganisms from previously saline soils were not more tolerant to a given adjusted EC than those in originally non-saline soil. Microbial biomass in all soils increased from day 0 to day 3, then decreased. The relative increase was greater in soils which had a lower microbial biomass on day 0 (which were more saline). Therefore the relative increase in microbial biomass appears to be a function of the biomass on day 0 rather than the EC. Hence, the results suggest that microbes from originally saline soils are not more tolerant to increases in salinity than those from originally non-saline soils. The strong increase in microbial biomass upon pea straw addition suggests that there is a subset of microbes in all soils that can respond to increased substrate availability even in highly saline environments.     

Effect of organic matter on the growth,nodulation, and nitrogen fixation of soybean grown under acid and saline conditions

Abstract

A field experiment was conducted to examine the effects of two organic materials (Bark and Tenporon composts) on the growth, nodulation and nitrogen fixation (measured as acetylene-reducing activity) of soybean plants (Glycine max L.) under acid and saline conditions. These organic materials were incorporated into acid and saline (induced by irrigating the soil with a NaCl solution) soils at 4% rate of application.

These composts tended to improve nodule formation in soybean under acid and saline conditions, especially in the plants treated with Bark compost. Acetylene-reducing activity was significantly (P<0.05) increased by these composts under acid condition.

These composts also tended to improve shoot growth under acid and saline conditions, presumably due to the improvement of the soil moisture status of the soils and nutrient uptake. These results suggest that the growth of soybean could be improved by the application of organic matter under acid and saline conditions.     

Salinity and the persistence of parathion in flooded soils

The persistence of parathion in five coastal saline soils of varying electrical conductivity and in one nonsaline soil sample was studied under flooded conditions. Parathion was decomposed faster in nonsaline soil than in saline soils and its stability increased with increasing electrical conductivity. The addition of salts to the nonsaline soil at 4, 8 and 16 dS^?1 increased the persistence of parathion. Nitro-group reduction, and not hydrolysis, was the major route of parathion degradation in saline and nonsaline soils. The accumulation of aminoparathion was less pronounced in saline soils than in nonsaline soil concomitant with slow degradation of parathion in saline soils. The inhibition of nitro-group reduction in saline soils was related to low microbial activities as reflected in decreased dehydrogenase activity and slow iron reduction.     

Plant roots and species moderate the salinity effect on microbial respiration,biomass, and enzyme activities in a sandy clay soil

The aim of this study was to determine the effects of plant absence or presence on microbial properties and enzyme activities at different levels of salinity in a sandy clay soil. The treatments involved five salinity levels—0.5 (control), 2.5, 5, 7.5, and 10 dS m^?1 which were prepared using a mixture of chloride salts—and three soil environments (unplanted soil, and soils planted with either wheat or clover) under greenhouse conditions. Each treatment was replicated three times. At the end of the experiment, soil microbial respiration, substrate-induced respiration (SIR), microbial biomass C (MBC), and enzyme activities were determined after plant harvest. Increasing salinity decreased soil microbial properties and enzyme activities, but increased the metabolic quotient (qCO₂) in both unplanted and planted soils. Most microbial properties of planted soils were greater than those of unplanted soils at low to moderate salinity levels, depending upon plant species. There was a small or no difference in soil properties between the unplanted and planted treatments at the highest salinity level, indicating that the indirect effects of plant presence might be less important due to significant reduction of plant growth. The lowered microbial activity and biomass, and enzyme activities were due to the reduction of root activity and biomass in salinized soils. The lower values of qCO₂ in planted than unplanted soils support the positive influence of plant root and its exudates on soil microbial activity and biomass in saline soils. Nonetheless, the role of plants in alleviating salinity influence on soil microbial activities decreases at high salinity levels and depends on plant type. In conclusion, cultivation and growing plant in abandoned saline environments with moderate salinity would improve soil microbial properties and functions by reducing salinity effect, in particular planting moderately tolerant crops. This helps to maintain or increase the fertility and quality of abandoned saline soils in arid regions.     

中国浙江省上虞市滨海盐土的物理化学性质及其实验超级光谱反射

45 and 50 composite soil samples were collected, respectively, from two agricultural fields, that were enclosed and reclaimed from coastal tidal-flat areas in 1996 and 1984 respectively, in Shangyu of Zhejiang Province, China, to investigate the physico-chemical properties and the hyperspectral characteristics of the saline soils and to make an assessment on their relationships. The reflectance spectra of saline soils were measured using a spectroradiometer in laboratory. The mean spectral curves of the saline soils from the two sites different in reclamation year showed that the saline soil taken from the recently reclaimed land with higher salinity demonstrated a lower reflectance intensity in the spectral region from about 550 nm to 2300 nm. In addition, nine absorption bands, i.e., 488 nm, 530 nm, 670 nm, 880 nm, 940 nm, 1400 nm, 1900 nm, 2 200 nm and 2 300 nm, were chosen as the spectral bands to investigate the relationships between soil physico-chemical properties by means of Pearson correlation analysis. Finally, the first two principal components were calculated from nine absorption bands and used to discriminate the saline soil samples taken from two sampled fields. The results indicate that it is feasible to detect physico-chemical properties of saline soils from fields reclaimed for varying time periods on the basis of the hyperspectral data.     

Carbon mineralization in saline soils as affected by residue composition and water potential

In saline soils under semi-arid climate, low matric and osmotic potential are the main stressors for microbes. But little is known about the impact of water potential (sum of matric and osmotic potential) and substrate composition on microbial activity and biomass in field collected saline soils. Three sandy loam soils with electrical conductivity of the saturated soil extract (EC_e) 3.8, 11 and 21 dS m^?1 (hereafter referred to EC3.8, EC11 and EC21) were kept at optimal water content for 14 days. After this pre-incubation, the soils were either left at optimal water content or dried to achieve water potentials of ?2.33, ?2.82, ?3.04 and ?4.04 MPa. Then, the soils were amended with 20 g?kg^?1 pea or wheat residue to increase nutrient supply. Carbon dioxide emission was measured over 14 days; microbial biomass C was measured at the end of the experiment. Cumulative respiration decreased with decreasing water potential and was significantly (P?<?0.05) lower in soils at water potential ?4 MPa than in soils at optimal water content. The effect of residue type on the response of cumulative respiration was inconsistent; with residue type having no effect in the saline soils (EC11 and EC21) whereas in the non-saline soil (EC3.8), the decrease in respiration with decreasing water potential was less with wheat than with pea residue. At a given water potential, the absolute and relative (in percentage of optimal water content) cumulative respiration was lower in the saline soils than in the non-saline soil. This can be explained by the lower osmotic potential and the smaller microbial biomass in the saline soils. However, even at a similar osmotic potential, cumulative respiration was higher in the non-saline soil. It can be concluded that high salt concentrations in the soil solution strongly reduce microbial activity even if the water content is relatively high. The stronger relative decrease in microbial activity in the saline soils at a given osmotic potential compared to the non-saline soil suggests that the small biomass in saline soils is less able to tolerate low osmotic potential. Hence, drying of soil will have a stronger negative effect on microbial activity in saline than in non-saline soils.