Research And Development Of Moisture And Compaction Compound Measurement System For Topsoil

Soil moisture and compaction are two important parameters in the process of crop growth,while the topsoil(0～5cm)moisture and compaction are important factors influencing rainwater infiltration,seed germination and breaking rate.In the market,the soil moisture and compaction sensor using plug-in measurement probe structure,can only measure a certain depth of soil moisture and compaction.In this study,the moisture and compaction compound measurement system for topsoil were developed,including sensor and data acquisition display platform.Finally,the parameters of topsoil volume moisture content,mass moisture content and bulk density were measured.The research content and innovation of this paper are as follows:Based on the theory of soil dielectric,the study used the FD(Frequency Domain)constant frequency impedance measurement method to design the surface parallel electrode probe and the soil moisture measurement sensor.By using it,the measurement of topsoil volume moisture content has completed.With a series of soil water calibration and the sensitivity test,the linear fit between the sensor output and the moisture content determines that the coefficient R2 is 0.9337 and the RMSE is 0.028.Based on the definition of soil compaction,the soil compaction sensor was designed by pressing method to obtain the information of soil compaction.The coupling model between soil mechanical resistance,soil moisture and bulk density was established.The soil mass moisture content and soil bulk density were analyzed by using the measured data.After testing,The prediction coefficient of topsoil mass moisture content is 0.9822,the root mean square error is 0.0089,the prediction coefficient of bulk density is 0.8053,and the root mean square error is 0.1035.The compound measurement sensor uses MSP430 microcontroller as the control core,with manual,automatic,continuous acquisition,historical data read and other work modes.For different environment,the PC-side and Android-side data acquisition display platform was developed.The study has achieved rapid collection of soil information,real-time data display,storage and other functions,and provided a set of high·quality soil moisture and compaction compound system for the fine agriculture.