Effects of slow or controlled release fertilizer types and fertilization modes on yield and quality of rice

There is limited information about the influence of slow or controlled release fertilizer (S/CRF) on rice yield and quality. In this study, japonica rice cultivar Nanjing 9108 was used to study the effects of three different S/CRFs (polymer-coated urea (PCU), sulfur-coated urea (SCU), and urea formaldehyde (UF)) and two fertilization modes (both S/CRF and common urea (CU) as basal fertilizer, S/CRF as basal and CU as tillering fertilizer) on rice yield and quality. CU only was applied separately as control (CK). Results showed that, rice grain yield, chalky kernel rate, chalky area, overall chalkiness, and the content of gliadin, glutenin, and protein, all showed the trends of UF>PCU>SCU within the same fertilization mode, and showed the trends of S/CRF as basal and CU as tillering fertilizer>both S/CRF and CU as basal fertilizer within the same type of S/CRF. In contrast, the contents of amylose, amylopectin, and starch, as well as taste value, and peak and hot viscosity showed trends of SCU>PCU>UF, and the trends of both S/CRF and CU as basal fertilizer>S/CRF as basal and CU as tillering fertilizer. Among S/CRF treatments and fertilization modes, taste values of cooked rice were positively correlated with amylose, amylopectin, and starch contents, as well as gel consistency, peak viscosity, hot viscosity, and cool viscosity, while negatively correlated with globulin, gliadin, glutenin, and protein contents. The types of S/CRF and fertilization modes are important for improving rice yield and quality. Compared to CK, higher yield and similar quality of rice was achieved with UF as basal and CU as tillering fertilizer, and similar yield with improved appearance and eating and cooking quality of rice was achieved with either both UF and CU as basal fertilizer, or PCU as basal and CU as tillering fertilizer.