Temporal and spatial decomposition analysis of nitrogen load and regional disparity of nitrogen load productivity in the Kumamoto area in Japan : An administrative-division-based approach using the Logarithmic Mean Divisia Index and the weighted Theil index
Li, Zhuolin ; Nakagawa, Kei LU
; Fujii, Hidemichi
; Hosono, Takahiro
and Berndtsson, Ronny
LU
(2026)
In Agricultural Systems
236.
- Abstract
Context: Nitrate contamination of groundwater, driven by human activities such as agriculture and urbanization, poses a significant global challenge. Objective: We aimed to identify the major drivers of nitrogen load (nitrogen pollution generation potential) and quantify spatial disparities in nitrogen load productivity across administrative divisions in the Kumamoto area from 1960 to 2020 under evolving agricultural policies and market dynamics. Methods: We applied the Logarithmic Mean Divisia Index decomposition and weighted Theil index to systematically examine nitrogen load dynamics and regional disparities in the Kumamoto area from 1960 to 2020. Focusing on crop production and farm animals, the analysis identified nitrogen... (More)
Context: Nitrate contamination of groundwater, driven by human activities such as agriculture and urbanization, poses a significant global challenge. Objective: We aimed to identify the major drivers of nitrogen load (nitrogen pollution generation potential) and quantify spatial disparities in nitrogen load productivity across administrative divisions in the Kumamoto area from 1960 to 2020 under evolving agricultural policies and market dynamics. Methods: We applied the Logarithmic Mean Divisia Index decomposition and weighted Theil index to systematically examine nitrogen load dynamics and regional disparities in the Kumamoto area from 1960 to 2020. Focusing on crop production and farm animals, the analysis identified nitrogen intensity, scale, and structural changes as key driving indicators of nitrogen load, tracing their temporal evolution under shifting agricultural policies and market forces. Results and conclusions: We show that (1) from 1960 to 1985, scale was the dominant driver of changes in staple crop production and farm animals. After 1985, farmland contraction and a decreasing number of farm animals allowed structural changes to become the primary determinant, indicating a shift toward high-quality agriculture. (2) Simultaneously, the weighted Theil index reveals that as regional specialization in crop production intensified, disparity shifted from within-to between-region. (3) Finally, by categorizing six development patterns at the administrative division level for a small watershed, this study exposes the limitations of one-size-fits-all policy and stresses the need for tailored strategies to enhance nitrogen load productivity. Significance: We offer region-specific recommendations for advancing sustainable nitrogen management and strengthening agricultural resilience.
(Less)
- author
- Li, Zhuolin
; Nakagawa, Kei
LU
; Fujii, Hidemichi
; Hosono, Takahiro
and Berndtsson, Ronny
LU
- organization
- publishing date
- 2026-06
- type
- Contribution to journal
- publication status
- published
- subject
- keywords
- Agriculture, Groundwater contamination, Logarithmic mean Divisia index, Nitrogen load, Weighted Theil index
- in
- Agricultural Systems
- volume
- 236
- article number
- 104766
- pages
- 16 pages
- publisher
- Elsevier
- external identifiers
-
- scopus:105036876690
- ISSN
- 0308-521X
- DOI
- 10.1016/j.agsy.2026.104766
- project
- The United Nations University Hub: Water in a Changing Environment (WICE)
- language
- English
- LU publication?
- yes
- additional info
- Publisher Copyright: © 2026 Elsevier Ltd. All rights are reserved, including those for text and data mining, AI training, and similar technologies.
- id
- b3a05767-f07d-4c2b-9d5e-78a08cda2f93
- date added to LUP
- 2026-05-20 08:44:44
- date last changed
- 2026-05-25 09:52:21
@article{b3a05767-f07d-4c2b-9d5e-78a08cda2f93,
abstract = {{<p>Context: Nitrate contamination of groundwater, driven by human activities such as agriculture and urbanization, poses a significant global challenge. Objective: We aimed to identify the major drivers of nitrogen load (nitrogen pollution generation potential) and quantify spatial disparities in nitrogen load productivity across administrative divisions in the Kumamoto area from 1960 to 2020 under evolving agricultural policies and market dynamics. Methods: We applied the Logarithmic Mean Divisia Index decomposition and weighted Theil index to systematically examine nitrogen load dynamics and regional disparities in the Kumamoto area from 1960 to 2020. Focusing on crop production and farm animals, the analysis identified nitrogen intensity, scale, and structural changes as key driving indicators of nitrogen load, tracing their temporal evolution under shifting agricultural policies and market forces. Results and conclusions: We show that (1) from 1960 to 1985, scale was the dominant driver of changes in staple crop production and farm animals. After 1985, farmland contraction and a decreasing number of farm animals allowed structural changes to become the primary determinant, indicating a shift toward high-quality agriculture. (2) Simultaneously, the weighted Theil index reveals that as regional specialization in crop production intensified, disparity shifted from within-to between-region. (3) Finally, by categorizing six development patterns at the administrative division level for a small watershed, this study exposes the limitations of one-size-fits-all policy and stresses the need for tailored strategies to enhance nitrogen load productivity. Significance: We offer region-specific recommendations for advancing sustainable nitrogen management and strengthening agricultural resilience.</p>}},
author = {{Li, Zhuolin and Nakagawa, Kei and Fujii, Hidemichi and Hosono, Takahiro and Berndtsson, Ronny}},
issn = {{0308-521X}},
keywords = {{Agriculture; Groundwater contamination; Logarithmic mean Divisia index; Nitrogen load; Weighted Theil index}},
language = {{eng}},
publisher = {{Elsevier}},
series = {{Agricultural Systems}},
title = {{Temporal and spatial decomposition analysis of nitrogen load and regional disparity of nitrogen load productivity in the Kumamoto area in Japan : An administrative-division-based approach using the Logarithmic Mean Divisia Index and the weighted Theil index}},
url = {{http://dx.doi.org/10.1016/j.agsy.2026.104766}},
doi = {{10.1016/j.agsy.2026.104766}},
volume = {{236}},
year = {{2026}},
}