The researchers conducted field experiments to determine the best amount of nitrogen, phosphorus, and potassium fertilizers for early rice in Qingcao Town. They found that the optimal quantities were 200 kg/hm2 of nitrogen, 91 kg/hm2 of phosphorus, and 120 kg/hm2 of potassium, resulting in a yield of 8,786 kg/hm2. Based on local agricultural practices, the recommended fertilization quantities were 200 kg/hm2 of nitrogen, 40 kg/hm2 of phosphorus, and 120 kg/hm2 of potassium.