The spatial variability of the soil water status and its temporal behavior are essential for hydrological modeling and agricultural management. Changes in atmospheric conditions such as precipitation usually cause large temporal dynamics in the soil water status, whereas inherent soil properties such as soil texture and topography maintain their spatial pattern with time. Our objective was to identify the relevant spatial and temporal processes underlying soil water behavior. Along a 48- by 3-m transect evenly distributed across two land use systems, i.e., cropland and grassland, the soil matric potential (Ψm) was measured on a weekly basis from May to October 2013 at 1-m intervals and at depths of 10, 30, 50, 70, 90, and 110 cm. The spatial variance of Ψm at the 10-cm depth decreased with weekly precipitation and the spatial median of ym in both land use systems, owing to the enhancement of lateral water redistribution by elevated soil wetness. Temporal dynamics in Ψm and its spatial variance diminished with soil depth. In contrast, the temporal stability of Ψm generally increased with soil depth because of the decreasing impact exerted by precipitation. According to Spearman’s rank correlation coefficients, the relative distribution of Ψm in space was more strongly correlated with relative elevation than with soil texture in the grassland. These results have direct implications for irrigation management.
|Journal||Vadose Zone Journal|
|State||Published - Aug 2016|
Bibliographical noteFunding Information:
We thank James D. Dollarhide, Sara Lawson, Michael Sama, Sleem Kreba, Thatiana Felski, and José Beraldo for their generous help in the field. Special thanks are due to the China Scholarship Council (CSC) for providing a Ph.D. scholarship to Y. Yang. This study was funded by the Youth Scholars Program of Beijing Normal University (2014NT04). This is publication no. 16-06-068 of the Kentucky Agricultural Experiment Station and is published with the approval of the Director. This work is supported by the National Institute of Food and Agriculture, USDA NRI no. 2008-35107-04649, and Multistate Project 1008973. Moreover, support of this work through the SB 271 program of the State of Kentucky is gratefully acknowledged.
© Soil Science Society of America.
ASJC Scopus subject areas
- Soil Science