Prospects for controlled application of water and fertiliser, based on sensing permittivity of soil
Prospects for controlled application of water and fertiliser, based on sensing permittivity of soil
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DOI：
10.1016/s0168-1699(02)00098-4
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发表时间：
2002-11-01
影响因子：
8.3
通讯作者：
Paul, W
中科院分区：
文献类型：
--
作者：
Paul, W
这项工作的总体目的是表明，通过测量土壤的复介电常数，可以获得水和肥料输入的反馈信号。众所周知，土壤介电常数的实部与体积含水量密切相关。因此基于此原理的传感器可用于控制灌溉。为了控制施肥，最新的发展是通过测量土壤介电常数的虚部来评估孔隙水电导率。冲刷实验表明，在农业环境下，这种“盐度”（孔隙水电导率，基于植物可用水中的离子浓度）主要受硝酸根离子的影响。油菜蒸渗仪实验表明，通过测量复介电常数，当盐度测量值校正为恒定土壤湿度下的盐度值（此处：田间持水量值）时，可以非常清楚地绘制出作物可用的实际盐量。总之，结果表明，控制施肥可以像控制灌溉一样简单。唯一的区别是时间常数更大。 (C) 2002 Elsevier Science B.V. 保留所有权利。
The overall purpose of this work was to show that by measuring the complex permittivity of soil, feedback signals can be achieved for both water and fertiliser input. It is well known that the real part of soil permittivity is closely connected to the volumetric water content. So sensors based on this principle are available for controlling irrigation. For controlling fertilisation, a newer development is the assessment of the pore water conductivity by measuring also the imaginary part of the soil permittivity. Washout experiments have shown that this 'salinity' (the pore water conductivity, based on the ion concentration in the plant available water) is mostly influenced by nitrate ions under agricultural circumstances. Lysimeter experiments with rape demonstrated that by measuring the complex permittivity, the actual amount of salts available to the crop could be mapped quite clearly, when the salinity measurements were corrected to salinity values at constant soil moisture (here: to values at field capacity). In conclusion, it is shown that a controlled fertilisation can be as straightforward as controlling irrigation. The only difference is the much greater time constant. (C) 2002 Elsevier Science B.V. All rights reserved.