Temporal Stability Analysis of Spatial Soil Water Content in an Irrigated Vineyard.

Field experiment was conducted in a 7.5 ha vineyard, located at northwest China, to asses temporal stability analysis of spatial soil water content, and its application in estimating field mean soil moisture was explored. Soil water content was measured at 135 geo-referenced locations for 17 times during the period of early May to late September in 2012 and 2013.  Soil water content was measured at three depths of 0 – 20 cm, 20 – 40 cm, and 40 – 60 cm. The results show that locations with high-level temporal stability tended to be different at different soil depths. Given the same number of measuring locations, using points determined by the temporal stability analysis of 2012 data outperformed the random and grid sampling in terms of estimating spatial mean in 2013. Correlation analysis with soil texture indicated that temporal stability of soil water content to some extent related to soil texture, and more so at deeper soil.