Enhancing Water Sustainability in Greenhouses: A Study on Rainwater Harvesting Potential for Crop Water Supply

Abstract

Climate change influences water availability and agricultural development in greenhouses in Tarakan City, North Kalimantan, Indonesia. Water scarcity can diminish crop yields, endangering food security and the environment's future sustainability. Despite the fact that the study area receives a lot of rainfall, much of it is wasted. During the rainy season, there is an excess of water, but much of it becomes runoff, and flooding is frequent. The study investigates the feasibility of rainwater harvesting from the greenhouse rooftop of the University of Borneo Tarakan to supply crop water demands. The research stages included an examination of dependable rainfall, an examination of harvested rainwater volume, and crop water demands in the greenhouse. During 2001-2020, the rooftop rainwater harvesting system of the 120 m2 greenhouse has the potential to yield an average volume captured of 22.26 m3/month and the cumulative volume captured reaches 1771.15 m3/year. The efficiency of the rainwater harvesting system reaches 100%, it can fully fulfill the water needs of tomato crops grown in the greenhouse with an average volume demand of 10.06 m3/month. The greenhouse's rainwater harvesting system has the capability to produce 12.20 m3/month of surplus water while maintaining environmental sustainability.