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为了探讨地下水位较高条件下根区湿润方式对梨树根和茎液流及水分平衡的影响 ,开展了较系统的试验研究。试验共设三种处理 ,即传统畦灌 (CFI) ,部分根干燥灌溉 (PRD)和分根区交替灌溉 (ARDI) ,分别使用土壤水分监测系统 (Enviro SCAN)和热脉冲探针监测土壤水分动态和梨树根和茎液流。结果表明在 PRD和 ARDI情况下湿润根区的根液流不仅大于干燥根区 ,而且也大于 CFI情况下的相同区域。复水后 ,ARDI干燥区的根液流比 PRD的恢复和提高快得多 ,并且比 CFI的大 ;ARDI的茎液流比 CFI的小 ,但比 PRD保持一侧根干燥时的大。在只有一侧根区灌溉时 ,ARDI和 PRD的日耗水量比 CFI的小。 ARDI和 PRD中湿润侧的根系具有水分吸收补偿效应 ,当干燥根区复水后能够提高水分的吸收能力 ,其程度与根区持续干燥的时间长短有关。逐日根液流与参考作物蒸发蒸腾量关系密切 ,但随着表面灌溉方式和湿润根区的不同这些关系明显的不一样。逐日茎液流与参考作物蒸发蒸腾量有关 ,而且在不同的表面灌溉方式下 ,土壤含水率相同时茎液流和参考作物蒸发蒸腾量的比率不同。与 CFI相比 ,ARDI和 PRD大约少用 5 0 %的灌溉水量 ,但是梨树的水分消耗量和茎液流并没减少相同的比例。表面湿润方式对水量平衡和液流的作用明显受到地下水位的影响。在
In order to investigate the effect of root zone wetting on the flow and water balance of pear roots and stems under higher water table conditions, a systematic study was carried out. Three treatments, CFI, PRD and ARDI, were used in this experiment. Soil moisture monitoring (Enviro SCAN) and thermal pulse probe were used to monitor soil moisture dynamics And pear root and stem flow. The results showed that in PRD and ARDI wetted root zone root flow is not only greater than the dry root zone, but also greater than the same area in the case of CFI. After rehydration, the root flow in the ARDI drying zone was much faster and greater than that of PRD, and the flow of ARDI was smaller than that of CFI, but larger than when PRD was kept dry on one side. When only one side of the root zone irrigation, ARDI and PRD daily water consumption less than the CFI. The wetted roots in ARDI and PRD have the effect of water absorption compensation, which can increase the water absorptivity after rewatering in the dry root zone, which is related to the duration of dry root zone. Daily root flow is closely related to the amount of reference crop evapotranspiration, but the relationship is obviously different with the different types of surface irrigation and wet root zone. The daily stem flow is related to the reference crop evapotranspiration, and the ratio of stem flow to reference crop evapotranspiration is different for the same soil moisture rates under different surface irrigation regimes. Compared with the CFI, ARDI and PRD use about 50% less irrigation water, but pear water consumption and stem flow did not reduce the same proportion. The effect of surface wetting on water balance and flow is clearly affected by groundwater level. in