Estimation of Photosynthetically Active Radiation (PAR) Distribution in Coconut-Based Different Intercropping Models

Abstract

Coconut (Cocos nucifera L.) is a vital crop in tropical regions, serving as a source of income and sustenance for millions. However, the traditional monocropping system of coconut cultivation often results in underutilizing land and resources. Intercropping, the practice of growing two or more crops in proximity, has emerged as a sustainable solution to maximize land use efficiency and increase overall productivity in coconut plantations. This study examines the distribution of Photosynthetically Active Radiation (PAR) in various coconut based intercropping systems to improve light use efficiency and overall productivity. This experiment was conducted at the Coconut Research Institute of Sri Lanka, PAR measurements were taken across matured different intercropping models, including coffee, cocoa, starfruit, pepper, and cinnamon, during peak solar hours. Results revealed significant variations in PAR distribution across intercropping categories, with the 'starfruit' category demonstrating the highest light penetration to the understory and 'cinnamon' the least. These findings underscore the importance of crop selection in optimizing light availability and resource utilization in coconut cropping systems. The study highlights opportunities for developing more sustainable, productive intercropping systems by tailoring light distribution to different crop requirements. The study found that PAR distribution followed a diurnal pattern, peaking between 11:30 am and 12:30 pm, and highlights the need to consider environmental factors and plant characteristics to optimize coconut-based agroforestry practices.