基于茎直径变化监测番茄水分状况的机理与方法  

Mechanism and methodology for monitoring tomato water content based on stem diameter variation

作　　者：王晓森[1,2] 孟兆江[1,2] 段爱旺[1,2] 刘祖贵[1,2] 

机构地区：[1]中国农业科学院农田灌溉研究所,新乡453003 [2]农业部作物需水与调控重点开放实验室,新乡453003

出　　处：《农业工程学报》2010年第12期107-113,共7页Transactions of the Chinese Society of Agricultural Engineering

基　　金：国家"863"计划(2006AA100209-06):作物水分状况茎变差技术及设备研制;国家自然科学基金(50779071):温室蔬菜需水特性与优质高效灌溉指标

摘　　要：该研究以春季温室番茄为试验材料,以筒栽和小区相结合的方法探索了番茄茎直径变化的机理与规律、外界环境因素对茎直径变化的影响以及如何消除气象因子对实测日最大收缩量(MDS)数值干扰等问题,目的在于为基于茎直径变化监测作物水分状况、实现自动灌溉的技术提供理论和实践依据。试验结果表明,番茄茎直径变化落后于叶水势变化,二者存在很好的相关性。番茄茎直径收缩过程是由韧皮部及木质部收缩同步构成,而恢复过程则是不同步的,木质部恢复较快。番茄盛果期蒸腾强度大于花果期蒸腾强度,蒸腾强度越大一天中最小茎直径出现的时间越晚,而其茎直径开始恢复的临界气孔导度值越小。番茄MDS的变化趋势和日均辐射的变化趋势一致,但变化幅度由土壤水分决定。当土壤相对含水率由田间持水率降至50%时,MDS随土壤水分的下降而变大,天气晴好时MDS能够很好的反映出土壤水分的差异;而当土壤相对含水率小于50%后,MDS随土壤水分的下降而变小。通过统计分析,由实测MDS与参照MDS相比的相对日最大收缩量(RMDS)指标基本上可以消除气象因子对监测结果的影响,稳定的反映土壤水分状况。Through tomato planted in barrels and plots in spring greenhouse,some experiments were carried out,which including the mechanism and law of tomato stem diameter variation,the influences of exterior environmental factors on its stem diameter variation,the way of eliminating meteorologic factors disturbances on observed Maximum Daily Shrinkage （MDS）,in order to provide theoretical and practical basis for the technology of monitoring crop water content and automatic irrigation system based on crop stem diameter variation. The results showed that the stem diameter variation of tomato lagged the leaf water potential variation for 1–1.5 h,but they had better correlation. The shrinkage process of tomato stem was consisted of synchronous shrinkages of xylem and phloem,but the xylem recovered its size sooner than phloem did in its recovery process. The daily transpiration intensity in tomato fruit period was bigger than that in its flower and fruit period,which caused the daily minimum stem diameter in fruit period occurred latter than that in flower and fruit period,and the critical stomata conductance values of stem recovery in fruit period was smaller than that in flower and fruit period too. Furthermore,the variation of tomato MDS shared the same trend with the daily average radiation,but its values scopes were regulated by soil water content. With the decrease of soil water content from field water capacity （FWC） to 50% relative soil water content,and the value of MDS got bigger. The MDS could reveal the difference of soil water content obviously in sun day,but the value of MDS got smaller along with the decrease of soil water content on the contrary with the condition of relative soil water content below 50%. In addition,through statistical analysis,the RMDS which was the value of MDS/MDS※ could eliminate the disturbances of meteorologic factors on observed MDS and reflect soil water content stably.

关 键 词：温室 水分 灌溉 番茄 茎直径变化 MDS 

分 类 号：S274.4[农业科学—农业水土工程]