This study evaluated the effects of methods of urea fertilizer application and the different irrigation methods on yield of green amaranth

This study evaluated the effects of methods of urea fertilizer application and the different irrigation methods on yield of green amaranth. This was with the view to establishing the best combination of urea fertilizer method of placement and irrigation method for green amaranth production in Southwestern Nigeria.The experiment was carried out in two agroecological zones (rainforest and derived savanna) in the dry season. The experiment was laid out in Randomized Complete Block Design with four replicates. The treatments were: (i) broadcasting + sprinkler, (ii) fertigation + sub-irrigation (iii) spot + sprinkler, (iv) drilling + sprinkler and (v)fertigation + sprinkler. Soil samples were collected from each plot at 0-15 cm depth before and after the experiment for routine laboratory analyses. The aboveground biomass of green amaranth was harvested and tissue samples were taken for the determination of dry matter yield and total tissue nitrogen. Nitrogen uptake, nitrogen use efficiency and nitrogen recovery of green amaranth were estimated. The data collected were subjected to analysis of variance and differences in treatment means were separated using Tukey test at 5% level of probability.Dry matter yield and nitrogen uptake from broadcast were significantly lower than that of subfertigation, spot, drilling and surface fertigatonin both rainforest and derived savanna zones. Nitrogen use efficiency and nitrogen recovery efficiency under broadcast were significantly lower than other fertilizer application methods in the two locations. The dry matter yield, nitrogen uptake, nitrogen use efficiency and nitrogen recovery efficiency were similar under the two irrigation methods in the derived savanna zone. However, these parameters were greater (p < 0.05) with capillary irrigation compared to sprinkler irrigation in the rainforest zone.It was concluded that either subfertigation, spot, drilling or surface fertigation fertilizer application method was best for optimum yield and Nitrogen use efficiency of green amaranth. Capillary irrigation produced better yield and Nitrogen Use Efficiency in the rainforest than sprinkler irrigation but not in derived savanna