*4.5. Practical Implementation of the Study*

The practical application of this study will be an effective tool to control N pollution. Several studies, including the current one, discuss effectively the FRT reducing the crop yield. Some of the published material indicates that even a huge decrease in chemical fertilization can control the yield losses in combination to the environmental safety [21–23]. The integrative use of controlled chemical fertilization in combination with organic fertilization can significantly improve the yield attributes and cost effectiveness and control environmental pollution. It is further recommended to conduct future research experiments on combined fertilization of organic and inorganic N, trying various fertilization resources, site-specific and crop-specific studies, following the short-term and long-term studies.

#### **5. Conclusions**

Because it produces the highest yield and total income, conventional fertilization is highly preferred by farmers. In our study, conventional fertilization had the lowest N use efficiency and highest N leaching among the treatments, and lower economic benefit and NEB than reduced conventional fertilization. Reduced conventional fertilization produced the optimal N fertilization approach. Although organic fertilization provides benefits such as improving soil texture and soil microorganism diversity, the high N leaching ratio and low economic benefits caused by organic fertilization mean that it is not ideal. Therefore, it is feasible to use organic fertilizer with chemical fertilizer to produce an optimum fertilization scheme. Further studies are needed to explore the optimal reduction in chemical fertilizer use and optimal proportions of chemical and organic fertilizer.

**Author Contributions:** Conceptualization, Y.G., M.A.B., X.L., H.W., X.Z. and H.L.; data curation, Y.Z., J.L., F.L., Q.-U.-A.R. and A.R.; formal analysis, Y.G., J.L. and F.L.; funding acquisition, X.Z.; Investigation, Y.G. and Y.Z.; methodology, M.A.B., X.L., H.W., A.R. and H.L.; project administration, H.W. and X.Z.; Resources, X.L. and H.L.; software, M.A.B., Y.Z., J.L. and Q.-U.-A.R.; supervision, H.L.; validation, F.L.; writing—original draft, Y.G.; writing—review & editing, M.A.B., Y.Z., J.L., X.L., F.L., H.W., Q.-U.-A.R., A.R., X.Z. and H.L. All authors have read and agreed to the published version of the manuscript.

**Funding:** This study was supported by the National Natural Science Foundation of China [grant number: U20A20114].

**Institutional Review Board Statement:** Not applicable.

**Informed Consent Statement:** Not applicable.

**Acknowledgments:** We sincerely thank Jungai Li for her substantial help in the data analysis. We also thank Andre Brito and Luiz Silva for the help of data analysis and language polishing work.

**Conflicts of Interest:** The authors declare no conflict of interest.
