The study looked at how different amounts of nitrogen fertilizer affect the growth of ryegrass under salty conditions. They found that salt stress can reduce the growth and nitrogen absorption of ryegrass. Adding nitrogen fertilizer can help the plants grow better and absorb more nitrogen. The best results were seen when the fertilizer was added 21 days after planting. Using too much nitrogen fertilizer can actually decrease the plants' ability to use nitrogen efficiently. The researchers suggest that using 240 kg of nitrogen per hectare is the best amount for ryegrass growth.