Cocoa Land Dynamics in Indonesia (1980–2025): A Statistical Assessment with Food System and Nutrition Implications

Abstract

Cocoa is an important agricultural commodity in Indonesia, but its cultivated area has changed substantially over time. Identifying when a sustained decline began is important for understanding the long-term trajectory of cocoa cultivation and supporting evidence-based agricultural planning. This study aimed to examine the temporal trend in cocoa plantation area in Indonesia from 1980 to 2025, identify the onset of a statistically significant decline, and project the future trajectory of cocoa land area. Annual cocoa land-area data from 1980 to 2025 were analyzed using graphical trend assessment, linear regression, and the Mann–Kendall trend test. Linear regression was applied to the decline phase to estimate the annual rate of change and to develop trend-based projections for 2026–2030. Model performance was assessed using the coefficient of determination and prediction error measures. Cocoa plantation area increased substantially from 47,082 ha in 1980 to a historical peak of 1,774,463 ha in 2012. A sustained decline began in 2013, with the area decreasing to 1,369,441 ha by 2025, representing a 22.83% reduction from the 2012 peak. Linear regression for 2013–2025 estimated an annual decline of approximately 36,217 ha (95% CI: −40,636 to −31,797), with a strong model fit (R² = 0.966; p < 0.001). The Mann–Kendall test confirmed a strong and statistically significant downward trend (τ = −0.974; p < 0.001). Under the assumption that the historical linear trend continues, cocoa land area is projected to decline to approximately 1.16 million ha by 2030. In conclusion, Indonesia's cocoa plantation area experienced a prolonged expansion followed by a statistically significant and sustained contraction beginning in 2013. Continued decline could substantially reduce the national cocoa-growing area over the coming years. These findings support the need for timely strategies focused on plantation rehabilitation, sustainable land-use management, productivity improvement, and long-term cocoa-sector sustainability.

Keywords: Cocoa plantation; Indonesia; land-use decline; temporal trend; linear regression; Mann–Kendall test; predictive modeling