# Mechanized wide narrow row densification configuration enhances japonica rice yield and head rice quality in Northern China

## TL;DR

A new rice planting method improves yield and quality in northern China by using a mechanized wide-narrow row configuration.

## Contribution

The study introduces a mechanized wide-narrow row planting configuration that optimizes japonica rice yield and milling quality.

## Key findings

- The wide-narrow row densification (WNDM) configuration produced the highest rice yield and head rice yield.
- WNDM achieved the highest soluble sugar content in grains, which correlated strongly with head rice yield.
- The local farmer’s method (LFM) provided the best processing and appearance quality, but WNDM offered a balanced improvement in yield and quality.

## Abstract

Planting configuration is an important factor in regulating rice yield and quality. This study aimed to elucidate the effects of mechanized transplanting configuration on yield formation and grain quality in northern China.

A two-year field experiment (2022-2023) was conducted using the japonica cultivar Liaojing 419, comparing four planting modes: local farmer’s method (LFM, equal row spacing), conventional densification (CDM), narrow-row densification (NDM), and wide-narrow row densification (WNDM). Measurements included yield and its components, biomass accumulation, soluble sugar content in grains, processing quality (head rice yield), cooking and eating quality, and starch granule morphology of milled rice powder.

The order of grain yield is WNDM>NDM>CDM>LFM, although NDM has the highest dry matter mass and productive panicles, WNDM has the highest product of total grain number (/m2) and thousand grain weight, which determines rice yield. LFM has the best processing quality (67.66 and 68.66 in head rice rate, respectively), appearance quality, taste quality and produced milled rice powder with the smoothest particle surfaces, followed by WNDM. WNDM led to the highest soluble sugar content in grains at 15, 25and 35 days after anthesis and highest head rice yield (7,895.51 and 8,066.34 kg/ha). The soluble sugar content in grains at 25and 35 days were extremely significantly (p<0.01) positively correlated with head rice yield.

The mechanized wide-narrow row densification configuration presents a balanced strategy that enhances grain yield and milling quality while maintaining acceptable eating quality. It offers a promising planting method for improving overall productivity in mechanized japonica rice systems in northern China.