Empirical Model of a Vertisol Evaporation as Tool for Management of Soil Practicability using Portable Lysimetric Station under Arid Land Context

Abstract

Soil compaction caused by traffics is commonly considered as one of the major’s problems in agriculture. Moisture content have a significant effect on amplifying soil compaction. This study aims to approach evaporation trend of a vertisol (40.47% clay, 39.30% loam and 20.23% sand) having an organic matter content of 1.5% in order to manage timing of its plasticity as a determinant factor inducing compaction created by the traffic of machines. A portable lysimetric measurement system was developed to evaluate soil evaporation trend. An empirical soil evaporation model was developed using three measurement campaigns according to different temperature and irradiance behaviors. Soil moisture content was evaluated with two sensors using conductivity and potential metric methods. Data were acquired using an Arduino UNO platform. Climatic datas obtained from meteorological station were used for computing evapotranspiration using Penman-Monteith model as reference for evaluation of the evaporation model output. According to different climatic behavior, the rate of vertisol evaporation showed a decrease in moisture content in three campaigns, the first one (C1) arranged from 46 to 8% and 43 to 8% in two repetitions respectively. The second one (C2) varied from 47 to 7 % and from 49 - 6 %. The third campaign (C3) changed from 47 to 6 % and 46 to 9 %. The occurrence of plasticity interval was between the 4^th to 11^th days in the first campaign, 6^th to 15^th days in the second campaign and between 10^th to 22^th in the third campaign. Finally, compared with simulated results developed by a model in Matlab Simulink, an important correlation has been showed. As conclusion we can predict plasticity limits from the lysimeter measurement and climatic datas.