Moisture Temporal Stability of a Typic Hapludox under Different Uses and Depths

Abstract

Temporal stability shows that specific within‐field locations can represent average moisture values for a period of time, reducing efforts of collecting and measurement field observations. The objective of this study was to analyze the temporal stability of soil moisture within a Hapludox, typical of Cerrado, a unique Brazilian biome (similar to savanna), located in the southwestern state of Goiás. Instant readings of volumetric soil moisture were done biweekly from November 2013to February 2014, using a portable TDRSensor with rods of 0.12 m in length, at 0‐ to 0.12‐, from 0.12‐ to 0.24‐, and 0.24‐ to 0.36‐m soil depths. The TDR sensor data were corrected and calibrated by volumetric water content data obtained from gravity method and soil bulk density measurements. To quantify temporal stability, we used nonparametric methods: Spearman correlation coefficient, average relative difference, and temporal stability index. Temporal stability on the field scale differed between the three sites/systems. Average soil moisture can be accurately estimated at only one georeferenced point for each site/management system, reducing measurement effort in long‐term studies. Core Ideas Moisture temporal stability reduce cost of field measurements. It is essential to planning monitoring programs of hydrology and irrigation. Represent a valuable support for future researches related to soil water management.