Modeling Water and Nutrient Movement in Sandy Soils Using HYDRUS‐2D

Abstract

Models help to describe and predict complex processes and scenarios that are difficult to understand or measure in environmental management systems. Thus, model simulations were performed (i) to calibrate HYDRUS‐2D for water and solute movement as a possible decision support system for Candler and Immokalee fine sand using data from microsprinkler and drip irrigation methods, (ii) to validate the performance of HYDRUS‐2D using field data of microsprinkler and drip irrigation methods, and (iii) to investigate Br−, NO3−, and water movement using annual or seasonal weather data and variable fertigation scenarios. The model showed reasonably good agreement between measured and simulated values for soil water content (R2 = 0.87–1.00), Br (R2 = 0.63–0.96), NO3−–N (R2 = 0.66–0.98), P (R2 = 0.25–0.78), and K (R2 = 0.44–0.99) movement. The model could be successfully used for scheduling irrigation and predicting nutrient leaching for both microsprinkler and drip irrigation systems on Florida's sandy soils. Core Ideas The model showed good agreement between measured and simulated values. NO3 and Br on Candler fine sand was leached out beyond the 60‐cm depth within <20 d. NO3 and Br at Immokalee leached in 20 and 25 d, respectively. The model appears ideal for irrigation scheduling under microirrigation. The model is ideal for predicting nutrient leaching for on Florida's sandy soils.

Parameterization of Soil Hydraulic Parameters for HYDRUS-3D Simulation of Soil Water Dynamics in a Drip-Irrigated Orchard

“…Kanzari [63] used HYDRUS-1D to simulate soil water dynamics and assess environmental risks due to the salination process by adjusting the shape parameter α. Wang [64] evaluated the performance of HYDRUS-1D and inversely calibrated the α and n parameters until the observed data were sufficiently well-fitted to the simulated values. Kadyampakeni [65], calibrated HYDRUS-2D in drip irrigation systems, modifying Ks and n, since they are the most sensitive soil hydraulic parameters for the prediction of water movement. Rai [47] used the HYDRUS-2D model to predict soil water and energy balance components under different conservation agriculture practices when working with pigeon pea and optimized them by inversely modelling the α and n parameters.…”

Simulation of soil water and nitrate transport in wheat field under various nitrogen fertilizer rates and rainfed conditions using HYDRUS-1D

“…Unlike NO 3 -N, which is considered to be present in free water, we assumed that NH 4 -N is adsorbed by soil particles according to the following formula (Kadyampakeni et al, 2018):…”