Climate‐smart Naga chili ( Capsicum chinense Jacq.) cultivation: Adapting fertilizer and irrigation practices for changing climate

Abstract

Limited winter rainfall and rising irrigation costs threaten sustainable Naga chili ( Capsicum chinense Jacq .) production in Bangladesh. However, the combined effects of crop‐specific irrigation and soil‐test‐based fertilization on Naga chili productivity and resource‐use efficiency remain poorly understood. Therefore, a field experiment was conducted to evaluate the influence of irrigation and fertilizer management on growth, yield, irrigation water use efficiency (IWUE), and nutrient use efficiency of Naga chili. The experiment was conducted in a randomized complete block design with two irrigation levels: conventional irrigation (CI) and climate‐smart irrigation (CSI), and three fertilizer management practices: farmers’ practice (FP), soil‐test‐based recommended fertilizer dose (RFD), and soil‐test‐based recommended fertilizer dose plus organic matter (RFD + OM). Growth parameters, fruit characteristics, and yield were not significantly affected by irrigation or fertilizer management. However, individual fruit weight was significantly affected by irrigation ( p  < 0.033), fertilizer management ( p  < 0.021), and their interaction ( p  < 0.005). CI produced higher individual fruit weight (6.5 ± 0.19 g) than CSI (6.1 ± 0.19 g), while FP and RFD + OM resulted in higher fruit weight than RFD alone. A significant irrigation × fertilizer interaction indicated that higher fruit weight under FP occurred only under CI. In contrast, CSI combined with soil‐test‐based fertilizer management maintained comparable fruit weight under reduced input conditions. CSI significantly increased IWUE ( p  < 0.001), while soil‐test‐based fertilizer management significantly improved nutrient (nitrogen) use efficiency ( p  < 0.001). The findings demonstrate that crop‐specific irrigation combined with soil‐test‐based fertilizer application can maintain Naga chili growth and yield while improving water and nutrient use efficiencies.