Comprehensive evaluation of rice quality in response to nitrogen application

In order to clarify the impact of nitrogen (N) application on rice quality, meta-analysis was utilized in this study based on rice (Oryza sativa L.) N application data published since 2000. The effects of N application on the protein content, processing, appearance, and cooking and eating quality of rice were systematically evaluated. The results showed that the protein content of rice increased linearly with the increase of N application rate. At the same time, N application increased milled rice rate, brown rice rate, and head rice rate, and the effect was best when N application rate was 91–135 kg N ha⁻¹. The gel consistency, amylose content, peak viscosity, hot-paste viscosity, and breakdown viscosity of rice were decreased by N application, and the reduction of each index was different under different N application rates. The amylose content of rice decreased with the increase of N application rate. Moreover, it was found that N application had no significant effect on chalkiness degree and chalkiness kernel rate. The results of this study can provide a reference for N application in the rice planting process to meet specific rice quality requirements.