Assessing temporal stability and spatial variability of soil water patterns with implications for precision water management
Assessing temporal stability and spatial variability of soil water patterns with implications for precision water management
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DOI：
10.1016/j.agwat.2004.09.020
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发表时间：
2005-04
影响因子：
6.7
通讯作者：
G. Starr
中科院分区：
文献类型：
--
作者：
G. Starr
土壤水分模式的时间稳定性可能对精准农业特别是水管理具有深远的影响。研究了两年生马铃薯(Solanum tuberosum L.)四块地土壤水分的时空变异性。和大麦(Hordeum visgare L.)轮换，以确定马铃薯产量的影响和基于稳定的土壤水分空间格局进行精确水管理的潜力。采用锤击式时域反射仪探头，沿10个样带重复测量土壤水分。采用灌溉、未灌溉和后期灌溉处理。绘制了时间稳定的土壤水分格局图，并与海拔高度和土壤颗粒大小分类进行了比较。时间稳定性模型解释了观测到的土壤水分变异性的47%。另外20%的变异性归因于随机测量误差。该模型在2002年进行了校准，根据野外边缘的一次测量，预测了2003年沿横断面的水分含量(均方根误差为0.05m3m−3)。现场尺度的趋势和延长(>；100m)干湿段沿横断面观察到。粒度越粗的土壤通常越干燥。旱地马铃薯产量随水分的增加呈线性增加。灌溉处理在干旱地区的产量相对较高，但在较潮湿的地区产量变化很大，往往很差。对于后期灌溉处理，干旱地区对增加水分的产量反应明显，而在潮湿地区，产量反应为中性到负值。对土壤稳定水分分布的了解可以为精确的水分管理提供有用的基础。
The temporal stability of soil water content patterns may have profound implications for precision agriculture in general and water management in particular. Spatio-temporal variability in soil water was assessed over four fields in a two-year potato (Solanum tuberosum L.) and barley (Hordeum vulgare L.) rotation to determine the potato yield implications and the potential for precision water management based on a stable spatial pattern of soil water. A hammer-driven time domain reflectometry probe was used to measure soil water content repeatedly along 10 transects. Irrigated, un-irrigated, and late irrigated treatments were employed. The temporally stable soil water pattern was mapped and compared with elevation and soil particle size classifications. A temporal stability model explained 47% of the observed variability in soil water content. An additional 20% of the variability was attributed to random measurement error. Calibrated in 2002, the model predicted water content (root mean square error of 0.05m3m−3) along transects in 2003 from a single measurement at the field edge. Field-scale trends and extended (>100m) wet and dry segments were observed along transects. Coarser particle size class soils were generally drier. Potato yield increased linearly with water content in un-irrigated areas. Yield was comparatively high in the drier areas for the irrigated treatment but was highly variable and frequently poor in the wetter areas. For the late-irrigated treatment, a strong yield response to added water was evident in the dry areas; however, the yield response was neutral to negative in the wetter areas. Knowledge of the underlying stable soil water distribution could provide a useful basis for precision water management.