Design and development of a front mounted on-the-go soil strength profile sensor

Abstract

Soil compaction is a great problem since it affects crop growth and yield. The causes of soil compaction are the managementpractices in agricultural production. A common practice is to implement subsoiling at a few centimeters below the hardpan.Management practices, field traffic, and variations of the soil’s physical and chemical properties throughout the field cause variations inthe soil compaction degree and depth. Subsoiling at certain depths can cause excessive energy consumption at a high cost. Therefore,agricultural tillage equipment could be improved by varying the tillage depth. Soil strength is the main indicator that depends on severalsoil properties such as bulk density, moisture, and organic soil texture content for determining the compaction level. The goal of thisstudy was to develop an on-the-go sensor. It measured soil strength at multiple depths in order to determine the depth of the compactedsoil layers. The mechanical frame of the sensor (body) was designed using Solidworks 3D CAD Design Software. Depth measurementswere based on the Programmable Logic Controller (PLC) system. The data-gathering algorithm was developed with Phoenix ContactPC WORX software. It recorded the data flowing from the load cells, calculated the depth of the hardpan, and altered the depth of thechisel. In order to calibrate the load cell and compensate for differences among the load cells, static tests were conducted in a laboratory.The consistency of the sensing tips in terms of the input load – output load harmony was in linear format with higher R2 values rangingbetween 0.98 and 0.99. Consequently, the on-the-go soil sensor was developed for variable depth subsoiling. Dynamic tests revealed thatthe sensor was capable of monitoring the soil strength through the profile in order to determine the compaction level and hardpan depth.Moreover, the sensor was capable of adopting itself to crop varieties that have different critical compaction levels for root penetration.