【作者】 袁大刚；

【导师】 刘世全； 张万钧；

【作者基本信息】 四川农业大学 ， 土壤学， 2003， 硕士

【摘要】 本文采取原位动态观测和室内分析相结合的方法研究天津开发区本特草坪、高羊茅草坪和泡桐行道树的节水灌溉指标，如灌溉饱和点与补偿点、灌水定额与周期等。研究结果表明： 由土面蒸发和植物蒸腾引起的土壤水分动态，包括季节性变化和剖面层次性变化。季节性变化按土壤耗水速率划分：本特草坪有弱、强、中和微4个耗水期；高羊茅草坪为弱、强与微3个耗水期；泡桐绿地为中、强与微3个耗水期。剖面层次据各土层含水量的变异系数划出水分活跃层、次活跃层和相对稳定层。不同绿地不同耗水期各层次深度不同。就绿地类型而言，活跃与次活跃层总深度：本特草坪≤高羊茅草坪＜泡桐绿地；就季节变化而言，弱耗水期活跃与次活跃层浅，强耗水期深，微耗水期较深。这是确定计划湿润深度的重要依据。 灌溉饱和点是灌溉时使土体各层充分湿润了的多点中子水分仪测定的容积含水量平均值。本特草坪0～100cm土层灌溉饱和点在35.1％～38.4％，上低下高；高羊茅草坪0～80cm土层在35.2％～37.9％，100cm土层为30.2％；泡桐绿地0～80cm土层在32.8％～34.0％，100cm土层仅24.6％。灌溉饱和点是决定灌水定额的因素之一。 灌溉补偿点和计划湿润层深度据植物根系分布、叶片气孔导度与土壤含水量的相关性及土壤水分层次性等确定。在草坪弱、泡桐中耗水期时，土壤高含水量时即须浅层灌溉补水，以满足其萌发需要；中、强耗水期，可低土壤含水量时深层灌溉补水；微耗水期，为安全越冬，又需中深层灌溉补水。 最大灌水定额由灌溉饱和点、补偿点和计划湿润深度确定。最大灌水定额=∑(各土层饱和点—诊断层达补偿点时各土层实际含水量)×计划湿润层深度。各绿地表现为强、中耗水期高，弱、微耗水期低。对照比试验处理明显要大。 灌水周期和灌水次数由灌溉饱和点与补偿点及土壤水分消耗速率决定，表现为强耗水期灌水周期短，灌水次数多，其后依次按中、弱、微耗水期灌水周期增长，灌水次数减少。对照灌水次数比试验处理多得多。 灌溉定额由灌水定额及灌水次数决定。试验中本特草坪565mm，高羊茅草坪239mm，泡桐绿地1100mm，即可满足其正常生长需要，且节水明显。 试验结束时土壤全盐没超过3g／kg，草坪呈下降，而泡桐绿地呈上升趋势，值得进一步研究。电导率与全盐相关显著或极显著，可用盐分传感器监测土壤盐分动态。 灌溉指标的定量确定，将为天津开发区实现智能化灌溉提供理论依据。更多还原

【Abstract】 In situ field dynamic monitoring results of soil moisture of three types of greenbelt in Tianjin economic development area, including bentgrass, tall fescue and paulownia, showed that the seasonal and vertical dynamics of soil water is the basis of water-saving irrigation.According to velocity of soil water consumption, the seasonal dynamics of soil water can be divided into different stages. Bentgrass greenbelt soil can be divided into slow consumption stage, quickest consumption stage, quicker consumption stage and slower consumption stage. Tall fescue greenbelt soil can be divided into slow consumption stage, quickest consumption stage and slower consumption stage. Paulownia greenbelt soil can be divided into quicker consumption stage, quickest consumption stage and slower consumption stage.In term of soil water coefficient of variation, the soil water profile in 0-100cm can be divided into 3 layers, i.e., hypoactive layer, hypoactive layer and correspondingly stable layer. These soil water layers varied along with soil water consumption seasons alternating. Different greenbelt types were distinguished from one another in different soil water consumption seasons.Soil water irrigation maximum was decided by soil physical properties. For bentgrass greenbelt soil, its soil water irrigation maximum was 35.1%-38.4% at 0-100cm depth. For tall fescue greenbelt soil, its soil water irrigation maximum was 35.2%-37.9% at 0-80cm depth, 30.2% at 100cm depth. For paulownia greenbelt soil, its soil water irrigation maximum was 32.8%-34.0%, 3at 0-100cm depth, 24.6% at 100cm depth.Soil water irrigation minimum and scheming wetted soil layer depth were decided by soil physical properties and plant physiological property. According to the correlativity between stomatal conductance and soil moisture, root system distribution and soil water profile, these greenbelt should irrigate when soil moisture is high, and their scheming wetted soil layer depth is shallow in slow consumption stage; irrigate when soil moisture is low, and their scheming wetted soil layer depth is deep in quickest consumption stage; irrigate when soil moisture is higher, and their scheming wetted soil layer depth is deeper hi slower consumption stage.Irrigation water requirement per time=(soil water irrigation maximum- soil water irrigation minimum) ?scheming wetted soil layer depth.Irrigation cycle and irrigation times were decided by soil water irrigation maximum, minimum and consumption velocity.Irrigation quota can be calculated by irrigation water requirement per time and irrigation times.Soil salt didn’t excess 3g kg-1 when experiments were finished, but paulownia greenbelt soil salt increased.Index system was made sure and will provide gist for intelligentlizing water-saving irrigation.更多还原