华北石质山区苹果树蒸腾规律及水分供求关系

采用由热扩散植物液流技术测算得到的、周期为2003年1月-2004年12月的苹果树蒸腾数据,结合同步观测得到降雨量,分析华北石质山区10年生苹果树蒸腾耗水规律及水分供求关系,旨在为该地区节水苹果园的发展提供必要的水分生态理论依据。结果表明:(1)苹果树蒸腾耗水量(TR)呈现出明显的日际变化或月变化特征。3-4月逐渐升高,5月-6月达到全年高峰值,7月份逐渐降低,10月以后迅速降低。2003年及2004年全年TR值分别为600.9mm、468.0 mm,主要生长期间(4月-9月)分别为502.6 mm、408.3 mm;(2)2003年和2004年降水与苹果蒸腾的比例均大于1.0,说明周年降水可以满足苹果蒸腾耗水的需要。但主要生长季节中的4月至5月降水量与蒸腾量比(R/TR)仅为0.2~0.4,故该时期苹果树水分供求矛盾比较突出,应加强水分补给。2003年苹果树萌芽期、新梢旺长期降水与蒸腾的比值(R/TR)分别为0.05、0.82,2004年该值分别为0.14、0.63。说明萌芽期至新梢旺长期(4月初至6月中旬)这种供求矛盾尤为突出,该时期正处果树水分敏感期,所以更要实施水分管理。

Transpiration and relationship between supply and demand of water for apple trees in the rocky mountainous area of north China

The transpiration rule and relationship between supply and demand of water for the apple trees in the rocky mountainous area of North China are analyzed through the experimental data of the apple trees sap flow and rainfall,which is measured by thermal dissipation sap flow velocity probe(TDP) and meteorology automatic monitoring system respectively.The trees are 10 years old.The experiment was conducted in Jan of 2003-Dec of 2004.The aim of this study is to provide the evidence for developing the water saving apple orchard in the area.The main results are as follows: The daily variations of apple trees transpiration(TR) is characterized with that TR rises gradually in March and April,and reaches a peak during May and June,falls down readily in July and it descends rapidly in October.In 2003,2004,the total TR was 600.9mm,468.0mm annually,and 502.6mm,408.3 mm in the main season,respectively.In terms of an entire year,the ratio of rainfall to transpiration(R/TR) is more than 1.0.So,as for annual value,there is no water supply and demand conflict,or water shortage and water stress in the experiment area.However,the ratio is only 0.2-0.4 during the periods of budding and rapid shoot growth(April-may),it is 0.05 and 0.82 in 2003,respectively,and 0.14,0.63 in 2004 respectively.And also,apple trees are very sensitive to water during these phonological stages,which indicates the imbalance of water supply and demand become more prominent in the above periods,therefore,water management appears to be more important.