Background Water is an important limiting factor for crop growth and development, water shortage is one of the most frequently encountered adversity with plant growth in arid regions, under the stress of adversity, a series of physiological changes usually occur in plants, the change of canopy temperature is the most direct manifestation of many physiological and biochemical processes of crops and is determined by the heat balance and the water vapour movement in the soil-crop-atmosphere cycle. Canopy temperature has been widely used in agriculture to evaluate the degree of drought as an important indicator of the amount and effectiveness of plant water.

Methods Three typical psammophytes of Caragana korshinskii, Salix psammophila, and Artemisia ordosicaas were choosen to be planted under 4 soil moisture treatments, each plant dug up 40 seedlings that were about 30 cm tall and had basically the same growth. The soil moisture treatments were defined account for A (5%-20%), B (20%-40%), C (40%-60%), D (60%-100%) of the field water holding capacity. Determination of plant canopy temperature, soil moisture content, air temperature, air humidity, poor water saturation pressure index, analysis of the plant canopy temperature under different soil moisture conditions, characteristics and differences, and to explore the psammophyte canopy temperature of meteorological factors and the response regularity of soil moisture.

Results Main results were as follows:1) in the same monitoring time, under the same background of meteorological conditions, the lower the soil moisture content of the plant, the higher the canopy temperature at the noon; 2) in the daily scale, the temperature of the canopy is influenced by meteorological factors and soil moisture as the daily cycle of meteorological factors changes, the correlation analysis shows that the influence of meteorological factors on canopy temperature is more significant than that of soil; 3) by calculating the sensitivity of plant canopy temperature and meteorological factor response under different soil moisture conditions, it was found that with the decrease of soil moisture content, the sensitivity of the temperature of C. korshinskii, S. psammophila, A. ordosicaas canopy to the response of meteorological factors increased. That is, the sensitivity coefficient of the temperature data of canopy temperature based on the temperature data of the canopy temperature based on the multiple time points on the daily scale can determine the soil moisture status of the plant. The lower the soil moisture content, the smaller the sensitivity of plant canopy temperature to meteorological factors.

Conculsions This study proved that using plant canopy temperature can be achieved for the determination of soil moisture condition of plants, and the field of vegetation water management provides a new convenient and effective way.