Simulation of Sugarcane Growth and Yield Under Optimized Subsurface Irrigation System

Abstract

The optimized subsurface irrigation system (OPSIS) is a newly developed subsurface irrigation system to irrigate upland crops. Although it is already evaluated for few crops using field experiments, further evaluation is required. Since field experiments are tedious, expensive, we need an alternative approach to evaluate the OPSIS. A well-calibrated and validated crop model is a fast-alternative option for developing and evaluating agronomic practices. Therefore, this study aimed to develop the modeling capabilities of APSIM to simulate the OPSIS. We conducted field experiments for three growing seasons (main crop and two ratoons), two planting seasons (spring and summer planting), and two separate crops to collect necessary data for calibration and validation processes. We scripted a new module named "OPSIS" to couple OPSIS to the APSIM engine. We parameterized, calibrated, and validated the APSIM to simulate the growth and yield of sugarcane with OPSIS. After firm parameterization and calibration, APSIM-Sugar can successfully simulate the growth and yield of sugarcane with OPSIS. However, the simulation of soil moisture dynamics and irrigation water use were not up to the standards. Although it gives quite reasonable results for growth and yield simulations of sugarcane, further studies are suggested to develop the simulation accuracy of soil water dynamics and irrigation water use through the OPSIS.