Detection of leaf area expansion promoted by additional fertilizer application on farmer’s paddy fields using multispectral images

Naoyuki Hashimoto, Yuki Saito, Shuhei Yamamoto, Masayasu Maki, Koki Homma

Research output: Contribution to journalArticlepeer-review

Abstract

To monitor the effect of additional fertilizer application, we measured leaf area expansion in farmer’s paddy fields using multispectral images (MS images) collected using unmanned aerial vehicles (UAV). Leaf area index (LAI) growth rate (LGR), which is defined as the slope of linear regression for time-series LAI, was used for evaluation. The image analysis, which considered fluctuations of solar radiation conditions, was applied to obtain LAI from images, and compared with LAI measured by LAI-2200. Three levels of ammonium sulfate (0, 10, 15 g m-2) were set as additional fertilizer treatments in 4 transplanted fields (2 Hitomebore, 2 Manamusume and 1 Datemasayume) and 4 direct seeded fields(Hitomebore)of a juridical agricultural union in Sendai (total 72 test plots, the area of which was 3 x 3 m). The additional fertilizer increased the number of panicles. However, there were no significant effects on the yield components. Both LAI-2200-based and MS-image-based LGRs at the center of the plot revealed significant effects only for the transplanted Hitomebore. However, significant effects were detected in both transplanted and direct seeded test plots in LGRs between the center and outside area (2 m from center) based on MS images. These results imply that the MS image by UAV can be used to monitor the effects of the fertilizer applied. The method will be useful to determine the optimal amount of fertilizer for each field by optimizing LAI growth.

Original languageEnglish
Pages (from-to)211-221
Number of pages11
JournalJapanese Journal of Crop Science
Volume90
Issue number2
DOIs
Publication statusPublished - 2021

Keywords

  • Effect of fertilizer
  • Leaf area index
  • Paddy field
  • Remote sensing
  • Unmanned aerial vehicle

ASJC Scopus subject areas

  • Food Science
  • Agronomy and Crop Science
  • Genetics

Fingerprint

Dive into the research topics of 'Detection of leaf area expansion promoted by additional fertilizer application on farmer’s paddy fields using multispectral images'. Together they form a unique fingerprint.

Cite this