Abstract

There is a huge maize yield gap in Ethiopia. The use of improper maize agronomic practices could contribute to maize yield gaps. Agronomic panel survey (APS) and a baseline survey were carried out by EIAR and CSA, respectively in collaboration with CIMMYT for three years (2015-17) to assess the rates and types of inorganic fertilizers applied; maize varieties used and plant densities maintained by farmers in major maize growing areas of Ethiopia. The APS were conducted by EIAR in 3 to 4 grids of 10 km × 10 km size in five zones while the baseline survey was conducted by CSA in nine zones following their own protocol. Results showed that most of the surveyed farmers (95%) grow improved hybrid maize varieties and >85% of them grow the improved varieties within the agro-ecology they were recommended for. Maize variety BH661 was the commonest maize variety in Jimma zone, BH660 in West Gojam and West Shoa zones, Limu in West Shoa and East Wollega zones and BH540 in East Shoa zone. Most of the surveyed farmers (89.5%) apply fertilizer for maize production out of which 75% of them apply inorganic fertilizers, 20.5% only organic and 4.5% both types. In most maize growing areas, farmers apply fertilizer rates very close to the blanket recommended rate of 100 kg NPS and 200 kg UREA. However, a consistently higher inorganic fertilizer rate was applied in West Gojam and the lowest in East Shoa Zones. The plant density at harvest was lower than any of the recommended plant densities for most of the maize growing zones. As an average of all zones and years, about 87.5% farmers maintained plant density at harvest below the recommended. Mean grain yield was above the national average for most of the study areas, but exceptionally higher for Gojam and Wollega zones and lower for East Shoa zone. There was a positive relationship between cob number and plant density, plant density and grain yield, cob number and grain yield, implying using sub-optimal plant density could potentially affect grain yield.

Key words: Fertilizer rate, grain yield, maize varieties, plant density, Zea mays.