工程、化学及新型生物措施在滨海盐土改良中的应用研究

发布时间：2018-04-13 21:20

本文选题：城市绿地 + 滨海盐土　；参考：《北京林业大学》2016年博士论文

【摘要】：我国滨海地区的城市化程度较高,但是在该区域广泛存在的滨海盐土,会对园林绿化植物产生诸多负面影响,从而降低城市绿地的观赏性及生态功能。本研究以大田条件下的实际应用为基础,以滨海地区城市绿化建设为目的,对滨海盐土不同改良措施的降盐效果进行了研究与评估,并针对实际情况提出相应的改良方案,以期提高滨海地区的城市绿地质量。本研究主要结果和结论如下：(1)在滨海地区新兴城区的城市绿化建设中,在条件允许的情况下,建议采取布设排盐暗管的工程改良措施。排盐暗管的布设深度为100 cm,上覆20 cm厚的碎石(粒径约3 cm)作为滤料,其改良成本为70元·m-2。与此同时,未采取工程改良措施的对照处理,其表层土壤(0-20 cm)发生了严重的次生盐渍化现象,全盐量约为初始的4.4倍(19.63±2.26 g·kg-1),苗木大量枯死,造成了严重的经济损失。(2)在滨海地区城市绿化的过程中,若采取的工程改良措施效果不佳,甚至未采取任何工程措施,则需要通过施入土壤改良剂的方式进行补救。本研究中,采取铺设碎石隔盐层的工程改良措施,其土壤盐分呈现出一定的表聚性,此时向土壤中施加沸石5 kg·m-2以及园林废弃物8 kg·m-2(改良深度20 cm),即可达到与排盐暗管处理改良效果相近的水平。此方案的改良成本,需在铺设碎石隔盐层的基础上,额外投入11.78元·m-2,共计约81.78元·m-2。对于未采取任何工程改良措施的区域,向土壤中施加磷石膏1 kg·m-2以及园林废弃物3.35 kg·m-2(改良深度20 cm),可在一定程度上抑制表层土壤返盐。虽然此方案的改良成本仅为4.39元·m-2,远低于上述工程改良处理。(3)本研究中,提出了一种采用蚯蚓改良滨海盐土的新型生物改良方式。在未采取工程改良措施的前提下,当园林废弃物的施用量达到6.5 kg.m-2时(以改良深度20 cm计算),试验用赤子爱胜蚓能够在滨海盐土中生存并自然越冬,同时降低滨海盐土的全盐量,改善滨海盐土的土壤肥力状况,促进植物的生长。在向每平方米土壤中添加6.5 kg园林废弃物作为饵料,并投放50条蚯蚓的基础上,额外施用1 kg的磷石膏以及0.4kg的红糖,可以进一步抑制土壤的返盐,巩固滨海盐土改良效果,降低土壤次生盐渍化造成的损失。此方案的改良成本约为10.60元.m-2,且具有一定的可持续性,为磷石膏及园林废弃物的资源化再利用提供了可行的方案,有利于循环经济的发展。
[Abstract]:The urbanization degree of coastal areas in China is relatively high, but the littoral salt soil, which exists widely in this area, will have many negative effects on the landscape plants, thus reducing the ornamental and ecological functions of urban green space.Based on the practical application in the field condition and the urban greening construction in the coastal area, the paper studies and evaluates the effect of the different improvement measures of the coastal saline soil, and puts forward the corresponding improvement scheme according to the actual situation.In order to improve the quality of urban green space in coastal areas.The main results and conclusions of this study are as follows: (1) in the construction of urban greening in the new urban area of coastal area, it is suggested to adopt the engineering improvement measures of laying salt discharge pipe in the case of conditions permitting.The depth of desalination pipe is 100 cm, and 20cm thick crushed stone (about 3 cm diameter) is used as filter material. The improvement cost is 70 yuan m ~ (-2).At the same time, serious secondary salinization occurred in the surface soil without the control treatment of engineering improvement measures. The total salt content was about 4.4 times 卤2.26 g / kg ~ (-1), and the seedlings were withered and died in a large amount, and the total salt content was 19.63 卤2.26 g / kg ~ (-1), and the total salt content was 19.63 卤2.26 g / kg ~ (-1).In the course of urban greening in coastal areas, if the effect of engineering improvement measures is not good, or even no engineering measures have been taken, it needs to be remedied by applying soil improver.In this study, the soil salinity showed a certain degree of surface aggregation by adopting the engineering improvement measures of laying the stone barrier salt layer.At this time, the application of zeolite 5 kg m -2 and garden waste 8 kg m -2 (20 cm 路m ~ (2)) to the soil could reach a level similar to the improvement effect of the salt discharge dark pipe treatment.The improvement cost of this scheme is 11.78 yuan m ~ (-2), which is about 81.78 yuan ~ (m ~ (-2)).For the areas without any engineering improvement measures, adding phosphogypsum 1 kg m-2 to the soil and garden waste 3.35 kg m ~ (-2) (improvement depth 20 cm 路m ~ (-2)) can restrain the salinization of surface soil to a certain extent.Although the improvement cost of this scheme is only 4.39 yuan m ~ (-2), which is far lower than that of the above engineering improvement treatment, a new biological improvement method using earthworm to improve coastal saline soil is proposed in this study.On the premise of no engineering improvement measures, when the application amount of garden waste reaches 6.5 kg.m-2 (20 cm depth), the experiment uses Aisheng vermis to survive in coastal saline soil and live through the winter naturally.At the same time, the total salt content of littoral saline soil was reduced, the soil fertility of littoral salt soil was improved, and the growth of plants was promoted.On the basis of adding 6.5 kg garden waste per square meter of soil as feed and adding 50 earthworms, the application of 1 kg phosphogypsum and 0.4kg brown sugar can further inhibit soil salting and consolidate the improvement effect of littoral saline soil.Reduce the loss caused by secondary salinization of soil.The improvement cost of this scheme is about 10.60 yuan, and it is sustainable, which provides a feasible scheme for the recycling of phosphogypsum and garden waste, and is conducive to the development of recycling economy.
【学位授予单位】：北京林业大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S156.42

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