Effect of chemical fertilizer reduction on the quality of hybrid rice of different amylose contents.

Abstract

To promote the reduction and efficiency of chemical fertilizers in rice production, two hybrid rice varieties with different amylose contents (16.43% and 27.58%) were selected to study the yield and quality performance of different quality rice varieties under reduced nitrogen/phosphorus conditions. Thus, the specific mechanism of the long-term nitrogen/phosphorus reduction effect on the quality of low- and high-amylose content (16.43% and 27.58%) rice was investigated by comparative analyses of the rapid visco analyzer and X-ray diffraction patterns, amylose contents, and starch structures of the samples. The results revealed that the effect of nitrogen fertilizer on the quality and yield of the hybrid rice was greater than that of phosphorus fertilizer. Indeed, reducing the former increased the Wx gene expression and amylose content of the rice varieties. Moreover, it reduced the starch crystallinity of Yixiangyou 1108 (2.16%), increasing the space between the starch grains and thus, chalkiness. Reducing nitrogen/phosphorus application did not significantly affect the yield and quality of the high-amylose rice but affected that of the high-quality rice with lower amylose contents. Thus, for high-amylose rice created for processing, appropriate chemical fertilizer reduction will not affect their yield and processing demand. PRACTICAL APPLICATIONS: Fertilization with different nitrogen and phosphorus fertilizers will seriously affect rice quality. The rice varieties with low amylose content (AC) could produce high taste quality rice by increasing nitrogen fertilizer and decreasing phosphorus fertilizer. The rice varieties with relatively high ACs should reduce the application of nitrogen/phosphorus fertilizer to appropriately increase AC, which can be used to produce healthy food with high resistant starch.