Archives of Agronomy and Soil Science, vol.62, no.1, pp.93-107, 2016 (SCI-Expanded)
Sorghum is one of the water- and nutrient-use efficient crops raised in dry regions worldwide. A 3x3 split-plot experiment in randomized complete block design was conducted to study the effects of petroleum refinery waste aqueous ammonia (NH3) on irrigated fodder sorghum for two consecutive growing seasons. The main plots consisted of 0 (control), 40, and 80kgNha(-1), respectively, and the injection depths (surface 15cm, and 20cm depth) were assigned to sub-plots. A significant effect of NH3 on both fresh and dry biomass production was observed where the highest yield was recorded from the 80kgNha(-1) than the control and 40kgNha(-1), respectively. Sorghum biomass yield increased most when NH3 was injected at 20cm depth as compared to other depths. Biomass nutrient content and nitrogen-use efficiency were increased when 80kgNha(-1) was applied as compared to the control. The critical limit of K:(Ca+Mg), above which the tetany risk increases, did not exceed in sorghum biomass by NH3 fertilization. Results suggested that industrial waste NH3 equivalent to 80kgNha(-1) injected at 20cm depth can be a sustainable approach to fertilize irrigated sorghum growing as a forage crop.