Evaluation of a Self-Regulating Low Energy Clay-Based Irrigation (Sleci) System Using Bell Pepper (Capsicum Annuum) as aTest Crop

Abstract

The study evaluated the SLECI system's effectiveness, using bell pepper (Capsicum annuum) as a test crop. Five specific objectives were set to accomplish the aim of the study. Objective one aimed at assessing how irrigation water quality and soil properties influence the performance indicators of (SLECI) system. This objective was accomplished by undertaking a laboratory experiment, with soil type (clay, sand, and loam) and source of irrigation water (river, well, and tap water) as treatments. Performance parameters of the SLECI system, such as seepage rate, hydraulic conductivity, and drainage porosity, were recorded. Pearson correlation tests conducted at a 5% probability level indicated that eight (8) correlations (Zinc, Copper, Calcium, Magnesium, Sodium, Iron, Potassium, and SAR) were statistically significant to the performance of the SLECI system. In contrast, soil properties (bulk density, porosity (%), particle density, infiltration rate, soil salinity, and soil sodicity) were significant to the performance of the SLECI system. Objective two aimed to assess the response of bell peppers to different irrigation systems (watering, drip irrigation, and SLECI system) and fertilizer application methods (basal application and fertigation), under greenhouse conditions. Analysis of variance (p < 0.05) revealed that bell peppers grown under the SLECI system had significantly higher growth, yield, productivity, and quality parameters. Fertigation resulted in significantly superior growth, yield, productivity, and quality parameters. The interaction of the SLECI system and fertigation outperformed all the remaining interactions of the irrigation system and fertilizer application method for data collection. Objective three aimed at investigating the effects of SLECI system burying depth (5 cm, 10cm, and 15 cm) and fertilizer recommended application dosage (100% RAD, 80% RAD, and 60 RAD) on bell peppers under open field conditions. Analysis of variance (p < 0.05) showed significantly higher growth, yield, productivity, and parameters from a burying depth of 10cm. Among fertilizer application dosage treatments, 80% of RAD produced bell pepper plants exhibited significantly higher growth, yield, and productivity parameters. The best-performing treatment interaction was the SLECI system burying depth of 10cm and 80% RAD. Objective four aimed to assess bell peppers' response to saline irrigation water (0.54 dS/m (control), 2.0 dS/m, 4.0 dS/m, 6.0 dS/m, and 8.0 dS/m) using the SLECI system. Compared to the control (0.55 dS/m) increasing water salinity levels to 2.0 dS/m, 4.0 dS/m, 6.0 dS/m, and 8.0 dS/m resulted in decreased growth, yield, and productivity parameters of bell pepper. Objective five aimed at simulating moisture and salinity levels using MATLAB. A coefficient determination of 0.99413, 0.98613, and 0.96689 was observed between experimental and simulated results indicating the robustness of MATLAB in simulating water and soil dynamics in the soil. Overall, the research highlights the potential of the SLECI system to enhance agricultural land and water productivity.