Integrating water productivity and water footprint assessment for evaluating pocket fertigation in greenhouse melon cultivation

Abstract Water scarcity and increasing pressure on agricultural water resources require irrigation systems that improve water-use efficiency while maintaining crop productivity. Pocket fertigation delivers water and nutrients directly to the root zone and may improve irrigation performance through localized resource delivery. This study evaluated pocket fertigation under two irrigation-supply levels using water productivity (WP) and water footprint (WF) as complementary indicators in greenhouse melon cultivation. Greenhouse pot experiments were conducted over two growing cycles from June to December 2023 using a 2 × 2 factorial treatment structure with five plant–pot units per treatment combination. Two fertigation systems, conventional surface fertigation and pocket fertigation, were combined with irrigation-supply levels equivalent to 1.0 and 1.5 times pan evaporation (Epan). Yield, fruit sweetness, WP, and WF were evaluated. Growing cycle significantly affected yield, fruit sweetness, WP, and WF, while irrigation-supply level significantly affected yield. A significant interaction between growing cycle and irrigation-supply level was also observed for yield. In contrast, the fertigation-system main effect and its interaction with irrigation-supply level were not significant for yield, WP, or WF. The second growing cycle (GS2) generally exhibited higher yield and WP and lower WF than the first growing cycle (GS1); however, because different cultivars were used, these differences reflect the combined influence of cultivar and growing-period conditions. These findings highlight the importance of irrigation-supply level for melon yield under the experimental conditions evaluated.