Improving cotton simulation model, GOSSYM, for soil, photosynthesis, and transpiration processes

Authors: BEEGUM, SAHILA - University Of Nebraska; Timlin, Dennis; REDDY, RAJA KAMBHAM - Mississippi State University; Reddy, Vangimalla; SUN, WENGUANG - University Of Nebraska; WANG, ZHUANGJI - University Of Maryland; Fleisher, David; RAY, CHITTARANJAN - University Of Nebraska

Submitted to: Scientific Reports
Publication Type: Peer Reviewed Journal
Publication Acceptance Date: 4/28/2023
Publication Date: 5/5/2023
Citation: Beegum, S., Timlin, D.J., Reddy, R., Reddy, V., Sun, W., Wang, Z., Fleisher, D.H., Ray, C. 2023. Improving cotton simulation model, GOSSYM, for soil, photosynthesis, and transpiration processes. Scientific Reports. 13:7314. https://doi.org/10.1038/s41598-023-34378-3.
DOI: https://doi.org/10.1038/s41598-023-34378-3

Interpretive Summary: GOSSYM is an existing model for simulating cotton crop growth and development. The soil, photosynthesis, and transpiration simulation modules of GOSSYM are found to have certain limitations in their predictions. The present study improves these three simulation modules (soil, photosynthesis, and transpiration) in GOSSYM by replacing them with more robust modules based on advanced theories. Measured data of plant growth and development from the field and experimental crop growth studies were used to evaluate the performance of the modified GOSSYM model. Modified GOSSYM was found to improve the simulation of soil, photosynthesis, and transpiration processes, thereby improving the predictive ability of cotton crop growth and development. This research and the newly developed model will be helpful for scientists, agricultural managers, and policymakers interested in assessing the effects of soil, water, temperature, carbon dioxide dynamics, nutrient stresses, etc., on cotton crop growth and development and in making adaptation strategies.

Technical Abstract: GOSSYM, a mechanistic, process-level cotton crop simulation model, has a two-dimensional (2D) gridded soil model called RHIZOS that simulates the below-ground processes daily. Water movement is based on gradients of water content and not hydraulic heads. In GOSSYM, photosynthesis is calculated using a daily empirical light response function that requires calibration for response to elevated carbon dioxide (CO2). This report discusses improvements made to the GOSSYM model for soil, photosynthesis, and transpiration processes. GOSSYM's predictions of below-ground processes using RHIZOS are improved by replacing it with 2DSOIL, a mechanistic 2D finite element soil process model. The photosynthesis and transpiration model in GOSSYM is replaced with a Farquhar biochemical model and Ball-Berry leaf energy balance model. The newly developed model (modified GOSSYM) is evaluated using field-scale and experimental data from SPAR (soil-plant-atmosphere-research) chambers. Modified GOSSYM better predicted net photosynthesis (root mean square error (RMSE) 25.5 versus 45.2 g CO2 m-2 day-1; index of agreement (IA) 0.89 versus 0.76) and transpiration (RMSE 3.3 versus 13.7 liters m-2 day-1; IA 0.92 versus 0.14) and improved the yield prediction by 6.0 %. Modified GOSSYM improved the simulation of soil, photosynthesis, and transpiration processes, thereby improving the predictive ability of cotton crop growth and development.