Effect of Macro-Nutrient Combinations on Yield and Economic Returns of Potato

Low macronutrient levels in the soil greatly affect the yield of Potato (Solanum tuberosum L.) in Uganda. The study was undertaken to determine the effect of macronutrient combinations on yield of potato. This was done in 6 sites across south western Uganda. The 5 levels of N:P:K combinations were laid in split plot arrangement with Mode of Application (MoA) allocated to main plots and nutrient combinations allocated to the sub plots. The results indicated that basal application significantly increased potato yield. Macronutrient combinations led to increase in potato yield with application of 100:75:200 performing better on ware and in season 2. Application of 75:50:150 was good for seed production and in season one when rains are not sufficient. Season 2 was the best season in the performance of macronutrient combinations. Karengyere was the best site for the potato yield response to nutrient combinations. The results showed 100:75:200 and 75:50:150 macro nutrient combination options as the most profitable in ware and seed potato respectively. This was attributed to the changes in the rainfall patterns in the two seasons. There is need to upscale blending of fertilizers for specific crops and with consideration of the seasons and agro-ecological conditions.