# Optimizing panicle fertilizer application based on amylose content for balancing yield and quality of japonica rice

## TL;DR

This paper shows how adjusting nitrogen fertilizer based on rice variety amylose content can balance yield and quality in japonica rice.

## Contribution

The study introduces amylose-based nitrogen management strategies for optimizing both yield and grain quality in japonica rice.

## Key findings

- Normal-amylose varieties increased yield by 27.27% with high nitrogen but showed worse appearance quality.
- Low-amylose varieties improved milling quality but had reduced cooking quality under high nitrogen.
- Amylose content determines optimal nitrogen application for balancing yield and quality in japonica rice.

## Abstract

Panicle nitrogen application is a key agronomic practice for regulating rice yield and quality, yet its effects are highly dependent on genetic background, especially the amylose content of japonica rice varieties.

This study systematically examined the differential responses to panicle nitrogen fertilizer (0, 60, 120 kg N ha-1) in yield formation, grain quality, and starch properties among representative japonica rice genotypes differing in amylose content (normal vs. low).

Results revealed variety-specific regulatory patterns: normal-amylose content (NAC) varieties showed a stronger yield response, with a 27.27% increase under the N120 treatment, largely attributable to higher panicle number per unit area. However, these varieties also exhibited significant deterioration in appearance quality, such as increased chalkiness. In contrast, low-amylose content (LAC) varieties demonstrated a greater improvement in milling quality—head rice rate increased by 10.13% under N120—but a more pronounced decline in cooking/eating quality, evidenced by reduced peak viscosity, breakdown value, and taste score. These findings highlight the need for amylose-based differential nitrogen management strategies to simultaneously achieve high yield and superior quality, providing a theoretical foundation for precision rice production oriented toward “variety-specific cultivation and quality-targeted fertilization.”