Spatio-temporal variability analysis of soil volumetric moisture content on the field scale

Abstract

The objective of this study was to explore spatio-temporal variability characteristic of soil volumetric moisture content (SVMC) during wheat and maize rotation system. In the article, SVMC was determined by the Time Domain Reflectometry (TDR), a total of 104 soil moisture content data from sampling sites were collected from the surface layer (0–20cm) at the experiment field (117°3'55.74"E, 36°43'8.99"N) with the support of grid-sampling method, sample measurements were implemented on June 3rd and on September 24th, 2009. On each sampling point, we inserted vertically TDR probe to monitor soil moisture. Each moisture measurement was geo-referenced using a Differential Global Positioning System (DGPS). The statistical analysis results showed that the SVMC range from 2.65 to 4.65 covered approximately percent 67% of the total samplings on June 3rd, which indicated the important effects on the total statistical distribution. Approximately percent 76% of the total samplings range from 45.4 to 55.4 on September 24th. To analyze the temporal variability of SVMC, we developed the comparison analysis results also indicated that the spatial pattern of SVMC clarified the fundamental complicated factors of the spatial structures and the comprehensive factors, and the exogenous variable decreased the effects on the spatial variability of SVMC from percent 70.9% to 54.9%, the random factors dominated the spatial variability of SVMC. The spatial distribution map of SVMC by Kriging interpolation was better to help us precisely and well understand the spatial distribution pattern of the SVMC of wheat-maize rotation system on the field scale.