The study looked at how returning wheat straw to the field and using different levels of nitrogen fertilizer affected the yield and growth of two types of rice. When all the wheat straw was returned, the rice yield increased with a certain level of nitrogen fertilizer. However, when no wheat straw was returned, the rice yield increased with higher levels of nitrogen fertilizer. Overall, returning all wheat straw to the field led to higher rice yield, tiller rate, and spikelet amount compared to not returning any wheat straw. This suggests that returning all wheat straw to the field can be beneficial for rice production.