Modelling the Geometry of Wetted Zone in Soil Based Growing Media Under Drip Irrigation

Abstract

Water shortage is a serious issue that cripples agricultural production worldwide. One of the most important technologies for the arid and semi-arid regions is drip irrigation. In designing and maintaining the drip irrigation system, knowledge on the depths and widths of the wet soil zone plays a major role. There is a lack of models under soil-based growing media to predict wetting patterns, since the applicability of available models was limited to soil only. Therefore, the objective of this study was to construct a dimensional analysis model to estimate the depth and width of wetting patterns under various growing media. Therefore, a model was developed to determine the geometry of the wetted root area under different growing media using a semi-empirical model and dimension analysis method. The predicted values of wetted zones were compared with those obtained from field experiments performed on the same soil. The experiment included the determination of the maximum wetted zone depths and widths under various growing media. Based on RMSE, ME, and ModEF parameters, model performance was highly valued. It is therefore possible to use established models to predict wetting patterns under soil, soil + sawdust, and soil + coirpith with water source line application. Model developed in this study for different growing media was highly recommended based on ModEF. Therefore, estimated model can be best fitted to desire the emitter spacing in designing of drip irrigation system under soil, soil + sawdust and soil + coirpith. Thus, helps in efficient application irrigation and therefore it will increases in water use efficiency.