Effect of effective microorganism and gypsum amendments on nutrient leaching,pH, electrical conductivity,and Okra growth parameters under coastal saline soil

Nutrients losses through leaching are the main problem facing coastal saline soil. Effective microorganisms (EM) and Gypsum (G) at the application rate of 5%G and 10%G by weight were used as soil amendments. The pot experiment aimed to improve the leaching of nitrate (NO₃), ammonium (NH₄) and total nitrogen (TN) on the coastal saline soil. The EM+ 5%G treatment effectively reduced the content of NO₃ and NH₄ in the leachate by 86.59% and 68.18%, respectively. EM treatment reduced the leaching of NO₃ and NH₄ by 70.86% and 62.12% and EM+ 10%G reduced NO₃ and NH₄ by 11.80% and 50.76%, respectively. Moreover, the content of TN in leachate was reduced up to 13.23%, 5.80%, and 2.67% in response to EM, EM+ 5%G, and EM+ 10%G, respectively, compared to the control. These results indicate that EM combined with G as soil amendments can reduce leaching of nutrients and further support the regulation of a coastal saline soil pH and EC.     

The response of wildtype and mutant cultivars of soybean to salt stress - comparing vegetative and reproductive phases on the basis of leaf biochemical contents,RWC, and stomatal conductance

Soybean, as a major oilseed crop, is cultivated in many parts of the world including saline-affected regions. A four-replicated factorial experiment based on a completely randomized design with five salinity levels (control, 50, 100, 150, and 200 mM NaCl) and five wild-type and new mutant cultivars of soybean (Williams, Clark, M-4, M-7, and M-9) was done at two vegetative and reproductive phases to study leaf oxidants, antioxidants and osmolytes under salinity stress. The vegetative phase demonstrated higher K⁺:Na⁺ ratio, cell membrane stability, relative water content (RWC) and stomatal conductance to H₂O (gs) accompanied with lower oxidative stress, antioxidants and osmolytes contrasting to reproductive phase. At both phenological phases, saline stress stimulated antioxidative defense owing to the enhancement of oxidative stress. The results indicated that mutants possessed a better antioxidative system than their wild-types.     

滨海盐碱地基盘法造林试验初报

该研究以唐山市南堡盐场重盐碱地为例,采用基盘育苗、台田整地、客土穴移植树苗等措施,探讨滨海盐碱地基盘法造林技术。结果表明:基盘具有一定阻隔盐碱的作用,客土、草炭、蛭石和珍珠岩体积比以5:1:2:2的种基盘出苗率最高,且蛭石和珍珠岩组合占优势的基盘配方出苗率高于草炭占优势的基盘配方,基盘苗早期受外界环境的不利影响较大,不同配方的基盘对基盘苗的根系发育和地上部生长量的影响大小还有待研究。台田的排盐阻盐效果以南北两条“十”字型（炉渣）的最好,炉渣隔离层比建筑垃圾隔离层的排盐阻盐效果明显。客土穴具有较好的阻盐效果,大部分移植树苗成活。研究结果可为滨海盐碱地造林提供一定技术支持。     

Dynamics of calcium‐sodium exchange under unsaturated plow conditions

Abstract

An experiment was conducted in soil columns of 84 cm length and 5.7 cm inner diameter to determine the effect of degree of water saturation on the extent of replacement of sodium by calcium from the exchange sites. The experiment was performed by running 0.20 N calcium chloride solution through a saline‐sodic soil into a water table at the lower end at different rates less than the infiltration rate of the soil, thus obtaining unsaturated flow conditions. The effective or the apparent calcium exchange capacity of the soil was reduced significantly and nearly proportionally with a decrease in the degree of water saturation during the flow process. It is suggested that part of exchange sites become inaccessible during the unsaturated flow and that there must be some isolated locations away from the main water stream in which mixing or molecular exchange by diffusion is negligible.     

基于WebGIS的农田水肥盐碱监测与调控管理系统

监测水肥盐碱动态变化信息,分析诊断提出调控方案,提升盐碱农田生产管理水平。该文基于Web GIS平台、利用Silverlight与WCF技术研发盐碱农田水肥盐碱监测管理系统,基于统计学原理和作物水肥盐碱平衡与胁迫响应原理,构建了特征分析、诊断预警和调控决策3类15个模型,并进行系统集成应用。结果表明,系统融合数据采集、数据管理、统计分析、诊断预警、调控决策技术与实施管理措施形成了"六位一体"的全过程优化管理体系;模型数据处理分析结果科学有效,系统应用决策方案符合实际。在无棣县盐碱农田应用表明,管理方案有效缓解了水盐限制,促进了土壤肥力趋稳均衡,投入产出效益和生产决策效率明显提升;2014—2016年综合节水率达31.02%,氮磷钾节肥率分别达28.69%~63.14%、10.07%~67.98%、97.98%~100%,小麦玉米增产率接近预期。研究有助于利用信息技术手段推进盐碱农田水肥盐碱动态规律的探索和田间精准管理水平的提升。     

秦巴山区土壤信息系统的建设研究

棵间土壤蒸发是塔克拉玛干沙漠公路防护林耗水的重要组成部分。应用Micro-Lysimeters测定了1个灌溉周期内咸水滴灌下距林木不同位置处的土壤蒸发量。分析了土壤蒸发与水面蒸发的关系,通过一维平差处理对防护林土壤蒸发量进行了估算。结果表明,塔里木沙漠公路防护林棵间土壤蒸发具有明显的季节变化特征。试验初期棵间土壤蒸发量:根基部>距根基50cm处>距根基100cm处;第5d以后,根基50cm处>根基部>距根基100cm处。林地土壤蒸发随土壤含水量的减低呈整体下降趋势。通过估算,咸水滴灌下整个防护林年土壤蒸发总量为2.63×106 m3,占总灌水量的21.43%,生长季蒸发量占全年蒸发量的92.28%。     

江苏大丰麇鹿保护区不同改良措施对滩涂土壤的改良效应研究

在大丰市麋鹿保护区内,设置滩涂荒地(A样区)、挖沟排盐结合耐盐植物初步改良(B样区)、挖深沟作垄结合耐盐植物多年改良(C样区)和在C样区改良基础上进行覆被种植再改良熟化(D样区)共4个试验样区,按0～20cm和20～40cm两层采集土壤,测定土壤pH和总盐分含量,分析、评价不同改良措施对苏北淤泥质滩涂土壤的改良熟化效应...     

Effects of Zeolite on Soil Nutrients and Growth of Barley Following Irrigation with Saline Water

ABSTRACT

Soil salinity is a major abiotic factor limiting crop production but an amendment with synthetic zeolite may mitigate effects of salinity stress on plants. The objective of the study was to determine the effects of zeolite on soil properties and growth of barley irrigated with diluted seawater. Barley was raised on a sand dune soil treated with calcium type zeolite at the rate of 1 and 5% and irrigated every alternate day with seawater diluted to electrical conductivity (EC) levels of 3 and 16 dS m^?1. Irrigation with 16 dS m^?1 saline water significantly suppressed plant height by 25%, leaf area by 44% and dry weight by 60%. However, a substantial increase in plant biomass of salt stressed barley was observed in zeolite-amended treatments. The application of zeolite also enhanced water and salt holding capacity of soil. Post-harvest soil analysis showed high concentrations of calcium (Ca^{2 +}), magnesium (Mg^{2 +}), sodium (Na⁺), and potassium (K⁺) due to saline water especially in the upper soil layer but concentrations were lower in soils treated with zeolite. Zeolite application at 5% increased Ca^{2 +} concentration in salt stressed plants; concentrations of trace elements were also increased by 19% for iron (Fe^{2 +}) and 10% for manganese (Mn^{2 +}). The overall results indicated that soil amendment with zeolite could effectively ameliorate salinity stress and improve nutrient balance in a sandy soil.     

黄河三角洲盐碱地刺槐混交林对土壤脲酶活性的影响

以黄河三角洲盐碱地26年生刺槐＋臭椿混交林（RA）、刺槐＋白榆混交林（RU）和刺槐＋白蜡混交林（RF）为研究对象,以刺槐纯林（RP）和无林地（CK）为对照,研究刺槐混交林对土壤脲酶活性的影响。结果表明：1）同一林分中,土壤脲酶活性随土层深度的增加而减小;2）不同林分之间表现为刺槐混交林〉刺槐纯林〉无林地,RP、RU、RF、RA的脲酶活性分别是CK的4．02、4．74、5．08和5．01倍;3）在影响土壤脲酶活性的土壤因子方面,刺槐混交林较其纯林表现为降低了土壤密度、pH值和含盐量,增大了总孔隙度,增强了蓄水性能,增加了全氮、碱解氮和有机质的质量分数,增加了细菌和固氮菌的数量;4）总孔隙度、细菌、固氮菌、全N和有机质等土壤因子对刺槐混交林土壤脲酶活性的影响较大,建议用这些土壤因子作为评价刺槐混交林土壤脲酶活性的主要指标。     

闽江河口区盐-淡水梯度下湿地土壤氮形态及储量特征

为了阐明盐-淡水梯度下河口湿地氮形态含量及储量特征,对闽江河口湿地盐-淡水梯度下氮形态含量、储量及其影响因子进行测定与分析。结果表明：尤溪洲湿地、蝙蝠洲湿地和鳝鱼滩湿地芦苇植物下0-60cm土壤全氮含量平均值分别为0.33,1.12,1.60g/kg;有机氮分别为0.33,1.11,1.58g/kg;铵态氮分别0.97,12.36,20.04mg/kg;硝态氮分别0.85,0.87,1.24mg/kg;储量平均值分别为41.16,104.91,114.35t/km2;41.04,103.75,112.91t/km2;10.06,119.20,148.43kg/km2;713.83,887.18,1 270.36kg/km2,均表现为在盐-淡水梯度下,湿地土壤各种形态氮含量和储量尤溪洲湿地〈蝙蝠洲湿地〈鳝鱼滩湿地;有机氮对土壤全氮组成的贡献最大;盐-淡水梯度下湿地土壤不同形态氮含量及储量的差异主要受到多因子的调节作用。