温室环境因子驱动甜瓜水分传输机理分析与模拟  

Mechanism Analysis and Simulation of Water Transport Driven by Environmental Factors for Greenhouse Muskmelon

作　　者：张大龙[1] 宋小明[1] 杜清洁 焦晓聪 李俊 李建明[1] 

机构地区：[1]西北农林科技大学园艺学院,陕西杨凌712100 [2]威宁彝族回族苗族自治县农牧局,毕节553100

出　　处：《农业机械学报》2017年第2期232-239,214,共9页Transactions of the Chinese Society for Agricultural Machinery

基　　金：国家自然科学基金项目(31471916);"十二五"国家科技支撑计划项目(2014BAD14B06)

摘　　要：利用人工气候室控制空气温度、相对湿度和光合有效辐射量,根据水量平衡法控制土壤含水率,按照四因素五水平的二次回归正交旋转组合设计,对甜瓜蒸腾量进行模拟,并探讨各因子调控水分传输的机制。基于Jarvis模型建立环境因素驱动的多元非线性气孔导度模型,结合水汽扩散原理建立蒸腾量模型,模型预测精度良好。探究因素交互作用及其耦合调控效应,结果表明:除相对湿度对蒸腾表现为抑制作用,土壤含水率、空气温度和光合有效辐射均对蒸腾具有促进作用;土壤含水率与空气温度的单因素效应相似,随因素水平增加,蒸腾量线性升高;光合有效辐射量驱动蒸腾的单因素效应为开口向下的二次函数,当因素水平超过阈值后,蒸腾量逐渐下降。环境因素在驱动和调控蒸腾过程中均存在密切耦合和反馈效应,土壤含水率与温度对蒸腾调控的耦合效应趋近于平滑曲面,蒸腾量随两因素水平的升高而升高,在试验水平内两因素对蒸腾表现为协同促进效应;空气相对湿度减弱了水汽扩散驱动力,进而抑制温度和土壤含水率对蒸腾的驱动作用,且这种抑制作用随相对湿度的升高而更明显。Water transport through soil-plant-atmosphere continuum was a complex process,which was regulated at a variety of organizational and time scales. Quantification of the relationship between environmental factors, biophysical regulation and transpiration was critical for improving water use efficiency. Taking soil moisture,air temperature,relative humidity and photosynthetic active radiation as experimental factors,a composite quadratic orthogonal regressive rotation design of four factors and five levels was applied to characterize the co-ordination between environmental factors that driving and regulating transpiration of muskmelon. Soil moisture was maintained by weighing method and environmental factors were controlled by growth chambers. Transpiration and physiological parameters were determined under different combinations of environmental factors. According to stomatal behavior and vapour diffusion,a transpiration rate model was developed. Stomatal conductance was simulated by using Jarvis model with multiple environmental factors as model inputs. The proposed transpiration model had satisfactory performance with only meteorological input requirements,and thus it was an effective approach for calculating crop transpiration for greenhouse grown muskmelon. Characterization of main effect,single effect and marginal effect of environmental factors was determined. All of the environmental factors were positively correlated with transpiration rate except relative humidity. Correlation between transpiration and soil moisture,temperature can be described in linear functions with positive slopes.Whereas photosynthetic active radiation exhibited parabolic functions with transpiration rate. Relative humidity was negatively linked with transpiration. The present results demonstrated that environmental factors were tightly coupled with water transport. Coupling effects between two environmental factors werequantified by regression model,with other factors were uniformity maintained at a constant level.Individual contribu

关 键 词：甜瓜 蒸腾 环境因素 正交设计 耦合作用 水力导度 

分 类 号：S152.7[农业科学—土壤学] S625.51[农业科学—农业基础科学]