Optimizing the Productivity and Profitability of Potato (cv. Jelly) through Sustainable Fertilization in High-altitude Areas of Cameroon

Abstract

Potato production in the Western Highlands of Cameroon is constrained by variable soil fertility, altitudinal differences, and limited access to mineral fertilisers. This study evaluated the effects of altitude and fertilisation on the growth, yield, soil chemical properties, and economic performance of potato cv. Jelly in the Menoua department. The experiment was conducted from January to May 2023 at three sites located at 1,337 m (A1), 1,413 m (A2), and 1,514 m (A3) above sea level. Five fertilisation treatments were compared: an unfertilised control (T1), urban compost applied at 20 (T2), 40 (T3), or 60 t dry matter ha⁻¹ (T4), and mineral fertiliser NPK 11-11-22 + 5.5 MgO applied at 350 kg ha⁻¹ (T5). Tuber yield, post-harvest soil properties, and the value-cost ratio were assessed. The results showed that altitude and fertiliser treatments significantly affected tuber yield (P < 0.05). The highest overall yield was recorded at the highest altitude, 1,514 m (A3). At this altitude, treatment T2 (20 t ha⁻¹ compost) achieved the maximum yield of 28.56 t ha⁻¹, followed closely by the mineral treatment T5, with 28.09 t ha⁻¹. At lower altitudes, treatment T2 also outperformed the other treatments, generating the highest yield at 1,337 m (A1), with 20.74 t ha⁻¹, and at 1,413 m (A2), with 6.13 t ha⁻¹, although overall yields at A2 remained particularly low. Compost application, notably T2, T3, and T4, improved several post-harvest soil chemical properties, particularly pH, available phosphorus, exchangeable cations, and cation exchange capacity. The economic analysis revealed that only treatment T2 was profitable at the most productive altitudes (A1 and A3), whereas treatment T5 exhibited negative profitability values across all altitudes (A1, A2, and A3), rendering it unprofitable. Based on these results, it is recommended that the altitude of 1,514 m (A3) be prioritised for the production of potato cv. Jelly in the region. Furthermore, for sustainable and economically viable production, a moderate application of urban compost at 20 t ha⁻¹ (T2) constitutes the most suitable recommendation, as it maximises yield, restores soil fertility, and ensures positive financial returns.