ISSN 2375-088X
African Journal of Soil Science ISSN 2375-088X Vol. 7 (11), pp. 001-008, November, 2019. © International Scholars Journals
Full Length Research Paper
Comparative productivity of nitrogen-use efficient and nitrogen-inefficient maize cultivars and traditional grain sorghum in the moist Savanna of West Africa
S.O. Oikeh*, V.O. Chude1, G. J. Kling2 and W. J. Horst3
1National Special Program on Food Security, Abuja, Nigeria.
2107 Crop Science Building, Oregon State University, Corvallis, OR 97331-3002, U.S.A.
3Institut für Pflanzenernährung, Universität Hannover, Herrenhäuser Str. 2, D 30419 Hannover, Germany. Africa Rice Center, (WARDA), 01 BP 2031, Cotonou, Benin Republic.
Accepted 18 July, 2019
Abstract
Strategies to cope with low fertilizer use in West Africa include choice of crop (that is., sorghum vs. maize) and the development of nitrogen-use efficient maize (Zea mays L.) varieties. A two-year field study was undertaken to compare the N response of an N- use efficient maize (hybrid, cv. 8644-27) and a nitrogen-inefficient maize (cv. TZB- SR), and to compare the productivity of the two cultivars with a traditional grain- sorghum (Sorghum bicolor [L.] Moench) in the moist savanna agroecosystem in Zaria, Nigeria. The two maize cultivars were evaluated under three N levels (0, 60, and 120 kg ha-1). Sorghum (cv. ‘mori’) was evaluated under 0 and 120 kg N ha-1. Mean grain yield was 0.5 Mg ha-1 greater for N-use efficient than for N-inefficient maize, mostly because of its larger harvest indices for dry biomass and for N, and a greater N-utilization efficiency. In both years, with 120 kg N ha-1 applied, grain yield and grain-N were 54 to 275% higher in maize than in grain sorghum. Under nitrogen stress (zero-N), grain yield of the N-efficient maize was similar to that of grain sorghum. But sorghum had 2 to 3 times greater total aboveground dry-matter yield and 165 to 230% higher total N-uptake than the maize cultivars, suggesting that sorghum was exhausting the soil of a greater amount of mineral-N than maize. Results showed that even under limiting nitrogen supply, a maize-based system with N-efficient maize was potentially more ecologically sustainable than a sorghum-based system involving traditional grain sorghum.
Key words: Cereal-based systems, grain sorghum, moist savanna, N-efficient maize, N-inefficient maize, N-utilization efficiency, West Africa.