Effects of dry season irrigation and fertilizer micro-dosing on water application efficiency, agronomic performance and water use efficiency of <i>Amaranthus viridis</i>

In most arable regions of Africa, fertilizer application and irrigation are cultural practices to improve soil fertility and reduce plant water stress especially during the dry cultivation seasons. Their application is beneficial if value of increase in crop yield due to climatic changes is sustained and improved. This study investigated the effects of urea and irrigation on water application efficiency, agronomic performance and water use efficiency of Amaranthus viridis in a humid rainforest zone of southwestern Nigeria during the dry season. It was conducted during the late and early dry seasons of year 2022 and 2023 respectively at the Teaching and Research Farm, Ekiti State Polytechnic, Isan Ekiti, Nigeria. There were two methods of irrigation (sprinkler and capillary) combined with urea fertilizer micro-dosing application rates of 0 and 40 kg N/ ha by fertigation, broadcast, drilling and spot placement replicated in a randomised complete block design. The data obtained were subjected to analysis of variance using Duncan’s Multiple Range Test to separate the significant means at p<0.05. The capillary irrigation system when combined with fertigation significantly (P < 0.05) improved soil water application efficiency and water use efficiency of the amaranth over the sprinkler system. The micro-dosing application rate on the dry season capillary irrigation method was enough to support growth and obtain optimum yield of the leafy vegetable.