This study emphasizes the role of Prosopis cineraria (Druce) in promoting sustainability through its contribution to carbon sequestration and climate change mitigation. The accurate quantification of the aboveground biomass (AGB) of Druce trees is essential for assessing their potential in reducing carbon emissions, yet remains a significant challenge. To address this, the study aimed to (1) estimate the AGB using destructive sampling; (2) analyze variability in existing allometric biomass equations; (3) evaluate remote sensing and machine learning techniques for estimating AGB and carbon sequestration; and (4) develop and validate new allometric equations based on field and remote sensing data. The Druce trees, with diameters at breast height ranging from 20.7 to 28.97 cm, exhibited an AGB of 208.3 kg per tree, which corresponds with a carbon sequestration stock of 97.89 kg C/tree. This translates to an annual carbon dioxide sequestration potential of 0.36 t C/tree. The newly developed allometric model (Model-2) was found to demonstrate superior accuracy, with performance metrics including a mean absolute percentage error (MAPE) of 2.6%, relative bias of 5.3%, R² of 0.906, mean absolute error (MAE) of 0.151, and root mean square error (RMSE) of 0.189. These improvements highlight the significant role of remote sensing technologies in advancing sustainable carbon monitoring and offer a more precise tool for enhancing global carbon sequestration models. By integrating field-based measurements and advanced technologies, this study strengthens our ability to assess the carbon sequestration potential of trees, contributing to more sustainable management and climate resilience strategies.

In this study, the finite volume method was used to evaluate the thermal performance of a flat-plate solar collector used to dry agricultural crops. A 3D numerical model was created and used to predict the outlet air velocities and temperatures for three inlet air velocities. When compared with experimental measurements, the numerical predictions showed good agreement under all testing conditions. Then, the numerical model was used to predict the internal airflow and heat transfer characteristics of the collector. The internal baffles were found to increase the dwell time and efficiency but also promote flow separation, which resulted in flow loss. In addition, the collector has a transparent cover that results in a substantial heat loss, which can be mitigated by adding a vacuum gap between the flow inside the collector and the cover. Increasing the flow rate increased the heat loss and decreased the heat uptake, which decreased the temperature difference between the inlet and outlet of the collector. Because the heat was lost through long-wavelength radiation via the transparent cover and sidewalls, coating the absorber plate with black matte paint to increase the solar radiation absorption coefficient did not improve the drying performance.

In arid countries like Oman, fan–pad cooling systems are commonly used in greenhouse cultivation. However, in such harsh environmental conditions, a fan–pad cooling system can be inefficient, result in high water and energy consumption, and may cause plant and soil pathogens issues. To address these challenges, this study evaluated the technical performance of a greenhouse designed with the new concept of an on-grid, solar-powered, and fan-chiller tube bank (FCTB) cooling system, focusing on water use efficiency (WUE) and energy use efficiency (EUE) following pot-grown okra. In addition, greenhouse gas (GHG) emissions and financial aspects were evaluated through cost–benefit and cash flow analyses. This research was conducted with a Quonset side-walled single-span greenhouse equipped with a solar-powered FCTB cooling system and automatic scheduled irrigation system. Water and electricity consumption was recorded, and surplus energy supplied to the electricity grid was estimated. The greenhouse efficiencies were evaluated by computing the EUE, total WUE, cooling water use efficiency (CWUE), and irrigation water use efficiency (IWUE). The solar-powered FCTB greenhouse enhanced EUE, achieving a value of 1.16 and a positive net energy of 163.87 MJ·m⁻². The WUE, CWUE, and IWUE were 0.91 kg·m⁻³, 1.63 kg·m⁻³, and 2.07 kg·m⁻³, respectively. The economic assessment showed that okra cultivation with a solar-powered FCTB cooling system was economically unfeasible, as indicated by a benefit–cost ratio of 0.88. However, cucumber (IRR 46%, NPV 2.13 × 10⁴ USD) and cherry tomatoes (IRR 38%, NPV 1.98 × 10⁴ USD) demonstrated economic feasibility as supported by positive net present value (NPV) and the internal rate of return (IRR) values. Furthermore, incorporating solar energy with the FCTB cooling system enhanced the greenhouse’s sustainability, efficiencies, and profitability. This study recommends further research with this system for Oman’s seasonal effect with high-value crops and optimizing the size of the solar panel system to see how the energy and other efficiency components will vary.

Leaf water status is a key indicator for irrigation scheduling and early stress detection, but many spectroscopic prediction studies have mainly relied on