Let there be light: From passive agricultural sensing to active intervention.

Yin, Xiaobo · Science · 2025

review · Level V

Where this comes from

Abstract

In Thailand, the word <i>BaiKhao</i> (ใบข้าว)-meaning "rice leaf"-embodies a quiet agricultural revolution. For generations, farmers gauged crops' nitrogen fertilizer needs by visually assessing leaf greenness, a method vulnerable to variations in lighting conditions and human error. Today, the "BaiKhaoNK" mobile app transforms smartphones into optical sensors. Using built-in cameras, it quantifies chlorophyll levels through spectral analysis and recommends precise fertilizer doses. This innovation epitomizes agriphotonics, a field dedicated to harnessing light-based tools to monitor, analyze, and diagnose crops and their environments.