The study compared different methods for evaluating the efficiency of nitrogen fertilizer in wheat crops. They looked at long-term experiments, common fertilizer experiments, and tracing experiments in Henan Province. The results showed that using nitrogen fertilizer yield and considering external nitrogen is the most accurate way to evaluate fertilizer efficiency. N use efficiency alone may not give a complete picture. The study suggests that using a semi-quantitative approach based on long-term experiment data can help guide optimal nitrogen application rates for better crop growth.