Integrated management packages accelerate agroecological recovery and improve the economic viability of degraded coffee systems

Introduction Neglected and degraded coffee farms characterized by low productivity and farmer income are widespread in eastern Democratic Republic of Congo. This study evaluated the effectiveness and economic viability of integrated management packages (IMPs) for restoring soil health, agroecological functions, and coffee productivity in degraded systems. Materials and methods A 34-month field experiment evaluated five IMPs that combined a cover crop or intercrops with one-time application of cow manure, residue retention, and elephant grass ( Pennisetum purpureum ) hedges around plots and Calliandra hedges around blocks. The IMP treatments were distinguished by the cover crops or intercrop as: velvet bean ( Mucuna pruriens ), bushy rattlepod ( Crotalaria grahamiana ), elephant grass, and velvet bean–bush bean ( Phaseolus vulgaris ) rotation, and banana intercrop. A control with only Calliandra along block edges, was included. The six treatments were arranged in a randomized complete block design, each treatment replicated four times. Soil physical, chemical, and biological properties were assessed alongside coffee growth, survival, yield, and nominal costs and benefits. Results and discussion Coffee yield significantly increased in the IMP with velvet bean–bush bean rotation at 24 and 34 months, and with year-round bushy rattlepod cover at 34 months. All IMPs reduced coffee tree mortality, while relative stem diameter growth increased significantly at 34 months. Despite the improvements in coffee performance, minimal changes were detected in most soil chemical properties whereas earthworm population and some physical indicators improved suggesting early biological and physical recovery. The IMP with banana-coffee intercropping was the sole IMP to fully offset its costs within the first 24 months, though with a slower recovery in coffee productivity and soil health. The IMP with bushy rattlepod offset its costs from the 25th and 34th months without fully recovering the cumulative costs incurred over the 34 months. Elephant grass hedges significantly reduced coffee productivity near plot borders. Extrapolating the performance of central plants to whole plots suggests that elimination of these edge effects could increase yields and profits by 270-490%, shortening the return-on-investment period across the IMPs. These findings show that well-designed IMPs can accelerate the agroecological recovery and improve economic performance of degraded coffee systems.