Response Yield and Forage Quality of Panicum Maximum to Nitrogen Fertilization Rates under Saline Water Conditions in Tobruk Area-Libya

A field experiment was conducted in summer 2022 in the Haflz area, about 70 km east of Tobruk city to study the effect of saline irrigation water and rates of nitrogen fertilization on the growth, yield, and forage quality of the Panicum maximum. The experiment was implemented in split –block design with randomized complete block design (RCBD). Irrigation water saline concentrations represented the main factor, (control, 120, 5000, and 12000 ppm). Nitrogen fertilization levels in the form of urea N46% represented the secondary factor, (without fertilization, 100 and 200 kg N/ha). The results of variance analysis indicated that, showed significant differences (p˂0.05) in the effect of nitrogen fertilizations rates on all plant traits, as the nitrogen fertilization rate of 200 kg/h outperformed the rest of the fertilization levels in a direct relationship, meaning that the traits increased linearly with an increase in nitrogen fertilization rate for all growth stages. The analysis results indicated significant differences (p˂0.05) with the interaction effects between irrigation water salinity and nitrogen fertilization rates in all studied traits, where the combination of 120 ppm with 200 kg/ha exceeded the other treatments, while the combination of 12000 ppm with 0 kg/ha recorded the lowest averages for all studied traits. The study concluded that the resistance of panicum plants to irrigation with saline water improves utilizing nitrogen fertilization. Keywords: Panicum yield, irrigation water salinity, nitrogen fertilization rates.