Effects of biochar on rice yield, grain quality and starch viscosity attributes

Abstract

BACKGROUND Biochar can play a key role in improving paddy soil and productivity. However, there is limited information on the effects of biochar on rice quality and starch gelatinization. In this study, four rice straw biochar dosage treatments (0, 20, 40 and 60 g kg−1; CK, C20, C40 and C60, respectively) were set up to investigate rice yield components, rice processing, appearance and cooking quality, and starch gelatinization. RESULTS Addition of biochar increased the effective panicle, grain number per panicle and seed setting rate. However, it decreased the 1000‐grain weight, resulting in an increase in yield. In 2019, all the biochar treatments improved the head rice rate (9.13–11.42%), whereas in 2020 only the C20 treatment improved. Low biochar dosage had little effect on grain appearance. High biochar dosage significantly decreased the chalky rice rate by 21.47% and chalkiness by 19.44% in 2019. However, it significantly increased the chalky rice rate and chalkiness by 118.95% and 85.45% in 2020, respectively. Biochar significantly lowered the amylose content except for the C20 and C40 treatments in 2020, and the gel consistency. The C40 and C60 treatments significantly increased the peak and breakdown viscosities and decreased the setback viscosity compared with CK. Correlation analysis showed that starch gelatinization characteristics were significantly correlated with the head rice rate, chalky rate and amylose content. CONCLUSION A lower biochar dosage can improve the yield and milled rice rate and maintain a higher quality of appearance, whereas a higher biochar dosage can significantly improve starch gelatinization. © 2023 Society of Chemical Industry.

Biochar and Nitrogen Fertilizer Change the Quality of Waxy and Non-Waxy Broomcorn Millet (Panicum miliaceum L.) Starch

“…This difference could probably be attributed to the differences between the distribution of starch granules, the content of amylose, and the proportion of amylose and amylopectin [ 51 ]. The BV represents the heat resistance of starch, and a lower BV within a specific range results in higher heat resistance [ 52 ]. In this study, N150+B significantly reduced the BV of starch, indicating that N150+B can increase its heat resistance.…”

Genetic Improvements in Rice Grain Quality: A Review of Elite Genes and Their Applications in Molecular Breeding

“…More recently, several studies have investigated the potential impact of biochar application on rice grain quality. It has been suggested that biochar application can positively influence various grain quality traits, including milled rice rate, starch viscosity attributes, eating quality, and grain appearance, with the specific effects varying depending on the dosage of biochar used [184,186,187]. Furthermore, the combined application of biochar and a low nitrogen rate (135 kg/ha) has emerged as a promising approach for enhancing both yield and grain quality in a sustainable manner [184].…”