The combined effects of salinity and excess boron on mineral ion relations in broccoli     

C.M. Grieve  J.A. Poss  S.R. Grattan  D.L. Suarez  T.E. Smith 《Scientia Horticulturae》2010

Two plant stress factors, salinity and high levels of boron, often co-occur in natural and agricultural environments. Many investigations have been conducted to document the influence of the combined stresses on crop growth and yield. Only limited information, however, is available concerning the combined effects of the two stresses on mineral ion uptake and partitioning to shoot organs and tissues. Data for this study were obtained from an experiment conducted in greenhouse sand cultures with two water types: (1) a chloride-dominated system, and (2) sulfate-dominated waters characteristic of those present in the San Joaquin Valley of California. Each saline composition treatment was tested at three salinity levels (2, 12, 18 dS m⁻¹) and three B concentrations (0.046, 1.11, 2.22 mM; 0.5, 12, 24 mg L⁻¹). The gradient in B distribution in individual leaves sampled midseason was steep, with less boron accumulating in petioles than in the blades. The highest B concentrations (>100 mmol B kg⁻¹ dry weight) were found in leaf margins of plants grown in the low salinity-high boron treatments. These leaves were cupped upward, an unusual visual symptom characteristic of B toxicity. At final harvest, concentrations of B, Ca, Mg, Na, K, and Cl were highest in the oldest leaves on the broccoli shoots, decreasing acropetally to the heads. Total-P, however, was highest in broccoli heads, decreasing in the older tissues. Leaf-B accumulation was more closely related to salinity rather than to the concentration of Cl in the irrigation waters. Analysis of variance indicated that substrate B had little effect on Cl accumulation in salt-stressed broccoli leaves regardless of water type. No clear cut relationships were evident that would explain the reciprocal effects of B and Cl on crop yields.  相似文献   

河湖污染治理对策的调查研究——Ⅳ几个重大项目     

高光智  陈辅利  刘磊 《大连水产学院学报》2009,(Z1)

针对我国河湖污染治理领域的现状和存在问题,提出了污染源监控管理工程、污水大规模再生利用、调污治沙和荒漠生态建设工程、水的城镇-农业大循序利用、开发性河湖污染治理等5项重大工程,并阐述了建设这些工程的意义、目的、内容、原则。  相似文献   

浅谈构建节水型新唐山     

崔秀君 《现代农业科学》2009,(5):267-268

节水是一项促进经济社会可持续发展的长期措施,是贯彻落实科学发展观和建立和谐社会的具体体现。  相似文献   

A Deformable Model Interpretation Based on the Theory of Elasticity     

ZHANG Xiang wei  CHENG Si yuan 《保鲜与加工》2003,(4):11-14

Deformable models provide a unified account of a number of visual problems, including contour extraction, motion tracking as well as 3D reconstruction and stereo matching. To get a reality-based interpretation of the deformable model and its parameters, an approach originates from the theory of elasticity is proposed. The conclusion is helpful to further understanding the behavior of deformable model. A new way is provided to research deformable models from the theory of elasticity.  相似文献   

Drainage disposal and reuse simulation in canal irrigated areas in Haryana     

Joginder Singh  Ranvir Kumar 《Irrigation and Drainage Systems》1997,12(1):1-22

Nearly 60 per cent of the geographical area of Haryana state in Indian Union is underlain by saline ground water. The intra-basin transfer of surface water in the early sixties for irrigation has disturbed the hydrodynamic equilibrium resulting in waterlogging and salinization in large parts of the state. The existing inland drainage basin conditions did not permit the disposal of drainage effluent. The reuse system was therefore, integrated with the drainage system. A model RESBAL was coupled with the calibrated and validated on-farm water management model FAIDS and run for eight years to optimally design a series of connected reservoirs for the disposal of drainage effluent from an area provided with a subsurface drainage system. The possibility of the reuse of the disposed water for irrigation, aqua culture and salt harvesting was also studied comprehensively in order to maintain proper salt balance in the root zone.  相似文献   

国内城市污水污泥的特点及处理处置对策   总被引：12，自引：0，他引：12  

邱兆富  周琪 《中国沼气》2004,22(2):22-25

城市污水经过污水处理厂处理后,必然要产生大量的污泥.为避免城市污水污泥产生二次污染,必须对其进行妥善处理与处置.在分析了国内城市污水污泥特点的基础上,阐述了国内城市污水污泥的处理与处置技术现状以及目前的研究动态,并提出了自己的见解.  相似文献   

自定义构件在生物统计分析平台中的应用研究     

吴延熊  陈美兰 《北京林业大学学报》2001,23(1):52-55

该文讨论了生物统计分析平台以构件为基础的重要性和制作自定义构件的必要性 ,介绍了在开发工具Del phi中制作自定义构件的步骤和方法 .同时 ,介绍了在生物统计分析平台中应用的部分自定义构件 ,并以自定义构件每日一招为例 ,阐述了构件制作的方法和途径 ,以及需要注意的相关问题  相似文献   

生物砂滤池在中水回用中的应用     

闫伟伟  陈小红  顾睿  唐大平 《安徽农业科学》2015,(31)

[目的]研究生物砂滤池在中水回用中的应用.[方法]以某生态居民小区污水处理系统的出水为水源,分析了不同条件下生物砂滤池对TSS、CODCr、BOD5、TN、NH4+-N、TP去除效果及规律.[结果]该生物砂滤池对于各种污染物都有明显的去除效果,尤其是对TN和NH;-N有很高的去除率,处理后中水水质完全能够满足该生态小区杂用水和景观环境用水的需求.[结论]该研究为中水回周提供了理论依据.  相似文献   

Dyebath reuse in dyeing of nylon microfiber non-woven fabric with 1:2 metal complex dyes     

Joon Seok Koh  Yong Geol Kim  Jae Pil Kim 《Fibers and Polymers》2001,2(1):35-40

Dyebath used for metal complex dyeing of nylon microfiber was recycled to reduce the overall amounts of metal complex dyeing effluents. Instead of discharging the dyebath after each dyeing cycle, the residual dyebath was analyzed spectrophotometrically and reconstituted to the required concentration of dyes and auxiliaries. Dyebaths were reused eight times and the CIELAB coordinates of dyed samples were measured after each recycling. Color difference (ΔE*) between the sample dyed in the fresh bath and that from reused dyebath was maintained below 1.5. The levelness and fastness of dyed fabrics from recycled dyebath were not impaired either. Chromium content of each recycled dyebath was similar to that of the first residual dyebath.  相似文献   

三格化粪池厕所的功能定位及在农村改厕中的应用误区   总被引：2，自引：0，他引：2       下载免费PDF全文

张玉  吕明环  徐明杰  李傲  施云鹏  李亚惠  范彬 《农业环境科学学报》2021,38(2):215-222

三格化粪池厕所因价格低廉、运维简便，成为当前欠发达地区农村厕所革命的主要技术模式，但在实际应用中普遍存在对其功能定位的认识误区，对化粪池后期的正确使用、粪污的无害化处理及粪肥有效回用造成了不良影响。因此，本文通过溯源化粪池发展历程，分析其在不同卫生模式下的功能定位，并揭示三格化粪池厕所具有卫生性和环保性的历史使命。在此基础上，通过剖析部分地区当前农村改厕存在的3个典型误区，即采用普通水冲式便器、“管道收集+（集中型）大化粪池”和“收集+异地脱水干燥制肥”应用模式的问题，指出需重视化粪池正确利用，并结合农村改厕中化粪池应用提出合理化建议。  相似文献