摘要
以山地梨枣为试材,进行了枣树茎直径对土壤水势(WPs)、太阳辐射(Rs)、气温(Ta)、空气相对湿度(RH)等生态因子的响应试验研究。试验共设4个WPs区间的处理,连续测定枣树茎直径及不同生态因子的动态变化。结果表明:在果实膨大期,在-41—-390 kPa范围内,WPs越高的处理,其枣树茎直径(TD)越大;不同处理间枣树最大茎直径(MXTD)存在显著性差异,较高的WPs区间有利于茎直径的增加;MXTD是该期较为适宜的水分信息诊断指标。晴天时,茎直径日收缩幅度大;雨天白天时,茎直径基本处于同一水平,收缩不明显。TD与RH呈极显著正相关,与Ta呈极显著负相关关系,与Rs间无显著相关关系,RH与Ta是影响茎直径变化的最主要气象因子。综合考虑,枣树茎直径的微变化同时受到各种生态因子的影响,尤以RH、Ta、WPs的影响更为显著;WPs高时,WPs为影响茎直径变化的主要因子;WPs低时,RH成为影响茎直径变化的主要因子。
The jujube industry is highly developed in the Yulin district of northern Shaanxi Province. Because jujube fruit yield is often affected by variation in precipitation throughout the year, accurate irrigation is an important method for increasing the potential of the local jujube industry.
Water demand in jujube trees is most critical during two stages ： 1 ） anthesis and fruit set and 2） fruit development. In this study, the effect of different ecological factors, such as soil water potential （WPs）, solar radiation （Rs）, air temperature （ Ta）, and air relative humidity （RH）, on jujube trunk diameter （TD） contraction during fruit development was investigated. In addition, the most suitable indicator of TD contraction was determined for use in accurate irrigation management.
Research was conducted in a rainproof shed at the micro- irrigation demonstration station in Mengcha, Yinzhou, Mizhi, Yulin, China. Three-year-old pear-jujube trees were studied using four different WPs treatments： -41 to -51 kPa （T1）, -68 to -84 kPa （T2）, -96 to -135 kPa （T3）, and -311 to -390 kPa （T4）. Individual test plots, separated by cement enclosures and containing three jujube trees, were 6 m long × 1 m wide × 1 m high. Each treatment was applied to three test plots. WPs was monitored continuously with an EQ15 equilibrium tensiometer and controlled automatically using a drip irrigation system that supplied water whenever WPs reached a minimum value. TD was continuously measured with a linear variable displacement transducer （LVDT） ; atmospheric factors were recorded using an automated weather station. Collected data were analyzed using DPS statistics software, and figures and tables were generated with Excel.
The results showed that jujube TD contraction followed a U-shaped curve over the course of a day. In general, trunk diameter shrank during the day, reaching a minimum trunk diameter （MNTD） at 17：00-19：00; at night, trunk diameter expanded, with the maximum diameter （MXTD） occurring at 7：00-9：00. The interval between MNTD and MXTD was about 12 h. TD trended differently depending on growing period, weather, and WPs treatment. During fruit development, when WPs ranged from -41 to -390 kPa, TD increased with increasing WPs. MXTD was significantly different between the treatments, and higher WPs ranges resulted in increased trunk diameter. MXTD was an appropriate water-level diagnostic indicator at this stage. Trunk diameter growth （DG） increased at moderate WPs levels （T2 and T3 ）, but was inhibited when WPs was excessively high （ T1 ） or low （T4）. DG was also influenced by weather conditions, increasing greatly on rainy days because of the higher RH. In contrast, the TD daily shrinking range was larger on sunny days, with no increase observed on rainy days. TD had a significant positive correlation with RH （ correlation coefficient ca. 0.9 ） and a significant negative correlation with Ta （ correlation coefficient ca. -0.75 ）, but little correlation with Rs. Thus, RH and Ta were the major atmospheric factors influencing TD contraction. Overall, jujube TD contraction was influenced simultaneously by various ecological factors, most significantly RH, Ta, and WPs. At higher WPs ranges, WPs had the greatest direct influence on TD contraction, followed by RH; at lower WPs ranges, RH was the primary factor, followed by WPs. TD was not directly affected by Ta, regardless of WPs level.
出处
《生态学报》
CAS
CSCD
北大核心
2012年第17期5476-5483,共8页
Acta Ecologica Sinica
基金
863计划(2010AA10A302-1)
国家农业转化资金课题(2009GB2G000359)
关键词
枣树
茎直径
土壤水势
空气相对湿度
生态因子
jujube tree
trunk diameter
soil water potential （WPs）
air relative humidity （RH）
ecological factors
