Validation of Blended Fertilizers Based on Ethio-Sis Soil Fertility Map to Develop Site Specific and Crop at Halaba, Southern Ethiopia

: Balanced use of inorganic fertilizers has been the important tools to overcome soil fertility problems and enhance crop production and productivity. The experiment was conducted validate blended fertilizer to develop site and crop specific optimum rate recommendations based on Ethio-SIS soil fertility map in Halaba, southern Ethiopia, during the 2019 cropping season. The experiment was consisted of six treatments levels: (1) control or unfertilized, (2) farmers’ practice (100 kg ha -1 of NPSB + 50 kg ha -1 of Urea), (3) 100% of the recommended rates of N and P which is-138 N and 92 P, (4) 50% of the recommended rates of N and P from blended (NPSB) fertilizer and urea, (5) 100% of the recommended rates of N and P from blended (NPSB) fertilizer and urea and (6) 150% of the recommended rates of N and P from blended (NPSB) fertilizer and urea. The treatments were arranged in randomized complete block design with three replications. The result revealed that the maximum grain yield (8,240 kg ha -1 ), straw yield (18,435 kg ha -1 ) and biomass yield (25,858 kg ha -1 ) of maize was obtained from application 150% of recommended rate nitrogen and phosphorous from NPSB blended fertilizer plus urea source. The economic analysis indicated that the application of 150% of recommended rate nitrogen and phosphorous from NPSB blended fertilizer and urea source were gives net benefit value of (107113.50 ETB ha -1 ) with MRR of (9%). These results suggest that an appropriate use balanced fertilizer based on site and crop specific not only provides enough nutrients to the soil but also improves crop production and productivity. There for application of 150% of recommended rate nitrogen and phosphorous from NPSB blended fertilizer and urea source based on Ethio-SIS soil fertility map can be recommended to farmers for maize producers, that with assurance of economic returns in Halaba, Southerm Ethiopia and areas with similar agro-ecological and soil conditions. Finally, further investigation should be undertaken across years and different locations to confirm the current finding and for wider applicability.