Effects of potassium fertilization on grain yield, taste quality, and starch characteristics of rice (Oryza sativa L.) grain.

Abstract

Background: There is limited information on the effect of potassium (K) on the taste quality of rice. Field experiments with five K fertilizer application rates (0, 60, 120, 180, and 240 kg K₂O ha^-1) were conducted in 2019 and 2020 using two cultivars (Xiadao No. 1 and Shenliangyou 5814) to study the effects of K fertilization on grain yield, taste quality, starch components, and protein components in grains.

Results: Compared with a no-potassium treatment (K₀), K fertilization increased the grain yield significantly: by 57.29% for Xiadao No. 1 and 33.51% for Shenliangyou 5814. It did this mainly by increasing the number of rice spikelets per panicle and improving the seed-setting rate. K fertilization improved the taste value by 12.64% for Xiadao No. 1 and 10.83% for Shenliangyou 5814. Starch components, protein components, and viscosity parameters were also influenced by K fertilization. With increased K application, the amylose content and the ratio of amylose content to amylopectin content tended to increase. K fertilization increased the peak viscosity and cool paste viscosity, while decreasing the prolamin content and pasting temperature. Principal component analysis highlighted the importance of amylose content and the ratio of amylose content to amylopectin content in determining taste value, texture, and appearance.

Conclusion: Applying 180 kg K₂O ha^-1 of K fertilizer ensured high rice yields and taste quality, providing a basis for the production of high-yield and high-quality rice. © 2024 Society of Chemical Industry.