滨海重度盐碱土微喷灌与隔离层协同水盐调控机理

Microsprinkler irrigation with the characteristic of high frequency, small flow rate and long duration, can make water movement under unsaturated flow conditions, influence little on soil structure and conductive to leaching of soil salinity. The technology of setting isolation layer in the coastal highly-saline soil is an effective method to prevent the salt accumulation on the soil surface by capillary action as well as increasing the infiltration rate in salinity soil. The combination of the two technologies can fully leach soil salinity, inhibit salt accumulation, and achieve efficient exploitation highly-saline land. The project will focus on: the regulation of water-salt transport under different soil matric potential threshold of microsprinkler irrigation and the depth of isolation layer, especially on the upper and lower interfaces of isolation layer; the changes process and correlation among plant physiological and biochemical parameters, such as absorbing capacity of root water, root signal transduction, stomata behavior, photosynthesis, and so on, and the effects of water and salt regulation on plant yield; the water and salt dynamic response of different plant growth stages model. The result is crucial to get the reasonable soil matric potential threshold of microsprinkler irrigation and burial depth of isolation layer, optimal irrigation system, water regulation mechanism by setting sand isolation layer under microsprinkler irrigation, the technology parameters of microsprinkler irrigation, groundwater critical depth as well as providing theoretical supports for efficient and sustainable exploitation the coastal highly-saline soil in that area.

微喷灌具有高频率、小流量和长时间的特点，能使土壤水分处于非饱和运动状态，对土壤结构影响小，利于土壤盐分淋洗。在盐碱土中设置砂石隔离层，可起到破坏土壤毛管，阻止土壤表层返盐的作用。两项技术结合能充分淋洗土壤盐分，抑制盐分表聚，达到高效治理盐碱地的目的。本项目将重点研究：微喷灌不同土壤基质势阈值与隔离层不同埋设深度控制下滨海盐碱地土壤水盐运移规律；植物根系吸水能力—根源信号传导—气孔行为—光合作用等生理生化参数变化过程和互馈关系，及微喷灌与隔离层协同调控对植物产量的影响机理；建立基于植物不同生育阶段水盐动态响应模型，确定滨海盐碱地微喷灌最优基质势阈值及隔离层合理埋设深度，提出节水、控盐和高产的优化灌溉制度。旨在揭示滨海盐碱土微喷灌与隔离层协同水盐调控机理，科学确定滨海盐碱地微喷灌技术参数和地下水临界深度，实现滨海重度盐碱地高效、可持续开发利用提供科学依据。

江苏省滨海滩涂资源丰富，且具有较好的农业潜力，通过科学改造和利用，可作为非常重要的土地后备资源。本项目研究了隔离层条件下不同喷灌技术参数下土壤水盐运移及植物生长的影响，提出滨海盐碱地微喷灌合理的喷灌强度和喷水量阈值以及滨海重度盐碱地隔离层条件下微喷灌优化灌溉制度，为科学开发滨海盐碱地资源提供数据支撑和技术支持。本项目执行期间，在在Journal of Integrative Agriculture，Scientia Horticulturae，Ecological Engineering，Arabian Journal of Geosciences等国外期刊上发表论文6篇，且均为SCI收录；申请发明专利4项，其中1项获得授权参加国内学术会议2次；培养硕士研究生2名。