Soil volumetric water content measuring method based on one-chip microcomputer

Abstract

The invention discloses a soil volumetric water content measuring method based on a one-chip microcomputer and belongs to the field of an agricultural measuring technology. The measuring method comprises the following steps: 1, connecting an inductor L1 in series to a capacitor to form an LC circuit; 2, establishing a relation between resonant frequency f0 of the LC circuit and soil volumetric water content theta v; 3, establishing a one-to-one correspondence form of several f0 values and several theta v values; 4, connecting a measuring circuit to the LC circuit; 5, putting soil to be measured between two polar plates of the capacitor; 6, adjusting frequency values of the LC circuit to several resonant frequency f0 values in the step 3, and acquiring and recording a voltage value between the two polar plates of the capacitor under each frequency value so as to obtain several voltage values; and 7, finding the maximum value of the several acquired voltage values, identifying the frequency value of the LC circuit corresponding to the maximum value as the resonant frequency f0 of the LC circuit, and enquiring the form in the step 3 so as to obtain the soil volumetric water content theta v. The measuring method has advantages of high precision, automatic acquisition, good measuring reproducibility and convenience in operation.

Description

technical field [0001] The invention belongs to the technical field of agricultural measurement, and in particular relates to the measurement of soil volume water content. Background technique [0002] Soil moisture content is an important parameter measured in precision agricultural water-saving irrigation. Through the real-time monitoring of soil moisture content, we can understand the growth law of crops, and it is of great significance to provide a suitable growth environment for crops. [0003] The dielectric property method is a commonly used method in soil moisture measurement. The dielectric property method is to use the dielectric properties of the soil to measure the water content of the soil. The change of soil dielectric constant ε can well reflect the change of soil volume water content θv. [0004] In the dielectric method, time domain method (TDR), frequency domain method (FDR), capacitance method and other commonly used methods, researchers at home and abr...

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Problems solved by technology

[0006] In order to overcome the TDR method in the above-mentioned prior art, the circuit is complex, the design is difficult, the shallower soil cannot be measured, and the instrument is expensive; and when the FDR is at a low frequency, it is easily affected by soil salinity, texture and bulk density. A method for measuring soil volumetric water content based on a single-chip microcomputer is proposed, and the technical scheme adopted is:

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