A low-cost simple lysimeter soil retriever design for retrieving soil from small lysimeters

Abstract

A lysimeter-soil retriever (LSR) is a device used to retrieve the soil with minimum disturbance from lysimeters. This device makes the process of sampling intact soil layers from lysimeters easier and faster, especially when a large number of lysimeters are being sampled. In this study, mini lysimeters (200 mm diameter and 25 kg weight) were used to test fertilizers. A low-cost LSR was designed to aid the accurate removal of the soil from these lysimeters. This paper describes the design and testing of the suitability of a linear actuator for this application. This study investigates the influence of soil moisture on the retrieval and structural stability of lysimeter and LSR. The results revealed that soil with a high moisture level was more suitable as it showed lower disturbance for retrieved block, lower soil losses, minimal disturbance for roots and lower variation of soil block height and weight. The retrieval time was influenced by soil moisture level and were 48 and 52 seconds for low and high-moisture soil, respectively. The finite element model showed that the stress applied by the linear actuator on the lysimeter body and top-wood plate were 2.18 and 0.32 Mpa, respectively. These stress values were within the safe limit of the corresponding materials. It was found the selected linear actuator is suitable for soil retrieving from lysimeters packed with sandy-clay loam and sand. It showed consistent performance (stroke time and maximum force) after retrieval of 400 soil blocks. The suitability of this design for various soil types needs to be tested to determine its applicability in a broader range of scenarios.