Impact of Integrated Fertilization and Management Practices on Coffee Production in Butanyerera Province, Burundi (2014–2017)

Coffee is Burundi’s principal export crop, accounting for approximately 60–70% of foreign exchange earnings, yet the sector faces declining yields, strong production cyclicality, aging plantations, and deteriorating quality. This study assessed the impact of integrated fertilization and management practices on coffee yield and quality in Ngozi Province from 2014 to 2017. A randomized complete block design was implemented in four communes (Busiga, Kiremba, Mwumba, and Tangara). The experiment compared 144 fertilized plantations (organic, mineral, and mixed fertilization combined with plant protection) with 144 unfertilized control plantations. Coffee orchards were classified into four age groups (4–8, 9–20, 21–50, and ≥51 years). Data were analyzed using ANOVA and Pearson correlation tests to determine treatment effects and relationships between yield and quality indicators. Results showed that fertilization significantly increased yield (P < 0.001), with treated plantations producing nearly three times more (3.44–3.58 kg tree⁻¹) than controls (1.26 kg tree⁻¹), regardless of fertilizer type. Coffee tree age significantly affected yield, and the age × year interaction indicated cumulative benefits from repeated fertilization. Importantly, older plantations remained productive when properly managed. Fertilization also significantly improved quality. Floating cherry rates were reduced from 19.62% in controls to 6.40–7.30% in treated plantations, while bored cherry rates decreased from 1.87% to 0.31–0.38% (P < 0.001). Yield was negatively correlated with both floating and bored cherries. Overall, sustained and integrated fertilization practices substantially enhance productivity, stabilize production, improve quality, and mitigate aging effects in Burundi’s coffee systems.