论文部分内容阅读
The objective of this study was to explore spatial variability and temporal stability 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 samplings 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 a triple wire TDR probe to monitor soil moisture.Each moisture measurement was geo-referenced using a Differential Global Positioning System (DGPS) and five moisture measurements were made within a 1-m diameter circle, the average value was regarded as the each point measurement.Frequency statistics results of SVMC showed that approximately percent 67% of the total samplings range from 45.4 to 55.4 on September 24th per cent approximately percent 76%of the total number of samplings, which responds the whole statistical level.For the two times samplings, the comparison analysis results showed that the spatial pattern of soil volumetric moisture content clarified the fundamental complicated factors of the spatial structures and the comprehensive factors, temporal stability of SVMC is a reflection of the temporal persistence of spatial SVMC patterns, the results also indicated that 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, there is the better temporal stability of SVMC in the study.The spatial distribution map of soil moisture by Kriging interpolation is also better to help researchers precisely and well understand the spatial distribution of the SVMC located in the farmland of wheat-maize rotation system.