基于冠层温度的玉米缺水诊断研究

冠层温度是判断植物水分状况的一项重要指标。以玉米良玉11为试验作物,在2014和2015年玉米抽雄期(7—8月)进行了4种不同梯度的土壤水分胁迫处理,研究了作物冠层温度、冠气温度比以及冠气温度差等指标与土壤含水量的关系,分析了冠气温度比与生理指标气孔导度的关系。研究结果显示:当土壤含水量低于0.16 cm3·cm~(-3)时,植株出现了明显的萎蔫现象,这时冠层温度、冠气温度比、冠气温度差也都分别达到了其最大值34℃,1.2℃和5℃;随着土壤含水量增大到0.20 cm3·cm~(-3),冠层温度等指标均达到其最小值,约为30℃,1.0℃和1℃,且变化比较稳定,这时植株生长良好,说明土壤供水充足,植株未受到水分胁迫。冠层温度等指标与气孔导度有显著的线性关系,气孔导度随着冠层温度等指标的增加而线性降低,表明气孔关闭会使得冠层温度显著提升。

Research on water deficit diagnosis of maize based on canopy temperature

Canopy temperature is an important indicator to judge the crop water condition.The variety Liang Yull was used as test crop,and four different soil moisture stress treatments were carried out for tasseling stage of the maize in 2014 and 2015.The relationships between canopy temperature,canopy-air temperature ratio,canopy-air temperature difference with soil moisture were researched,and relationship between canopy temperature with stomatal conductance was analyzed.The results were shown that:when the soil water content was less than 0.16 cm3 ·cm-3,the plant was appeared obvious wilting,at this time,the canopy temperature,canopy-air temperature ratio and canopy-air temperature difference were reached the maximum as 34℃,1.2℃ and 5℃,respectively.Along with the soil water content was increased to 0.20 cm3 · cm-3,the canopy temperature,canopy-air temperature rate and canopy-air temperature difference were reached the least values about 30℃,1.0℃ and 1℃,at this time the plant growth was good,it was explained that soil water supply was sufficient and plant was not suffered water stress.There was the distinct linear relationship between the canopy temperature and stomatal conductance,the stomatal conductance was linearly decreased with increasing canopy temperature.It was indicated that stoma close will be let the canopy temperature notable increase.This research results can be provided the technical support for diagnosis of crop drought and drawing up the irrigation schedule.