Effect of integrated use of cattle manure and inorganic fertilizers on tuber yield of potato in Ethiopia

A field experiment was conducted to assess the effect of farmyard (cattle) manure (FYM) and inorganic nitrogen (N) phosphorus (P) fertilizers on growth and tuber yield of potato (Solanum tuberosum L.). The treatments consisted of factorial combination of 4 levels of FYM (0. 10, 20 and 30 t h-1) and three levels of inorganic NP fertilizers (0, 33.3%, 66.6% recommended rates) laid out in a Randomized Complete Block Design (RCBD) replicated three times. Results demonstrated that the application of 20 or 30 t ha-1 FYM + 66.6% of the recommended inorganic NP fertilizers significantly increased total tuber yield over the application of full dose of inorganic NP fertilizers without FYM in vertisol whereas in nitosol, the highest level of FYM (30 t ha-1) + 66.6% of the recommended inorganic NP fertilizers significantly improved total tuber yield over the application of full dose of inorganic NP fertilizers without FYM. The application of 10 t ha-1 FYM + 66.6% of the recommended inorganic NP fertilizers and 20 or 30 t ha-1 FYM + 33.3% of the recommended inorganic NP fertilizers gave a total tuber yield, which was on par with the tuber yield obtained due to the application of full dose of inorganic NP fertilizer alone, in both soils. Thus, the application of 10 t ha-1 and 20 or 30 t ha-1 FYM resulted in a saving of 33.3% and 66.6% of the recommended NP fertilizers, respectively without significantly reducing the total tuber.