1 Soil Science department, Earth Science Unit, Felix Houphouet Boigny University, Cocody, 22 BP 582 Abidjan 22, Côte d’Ivoire. 2 Biology Science department, Peleforo Gon Coulibaly University, Korhogo, Biology Sciences, BP 1328 Korhogo. Côte d’Ivoire. 3 Agronomy department, Institue d’Economie Appliquée-IER, BP 16 CRRA, Sikasso, Mali. 4 Lowland rice breeding, Africa Rice Center, 01 BP 2031 Cotonou, Bénin.
Missing tool for site specific nutrient management can impaired the sustainability of rice (Oryza sativa L.) production. To improve knowledge of nutrient constraints in irrigated plain of the Sahel zone in West Africa, an omission trial was conducted in 2007 and 2008 in Baguenida (Mali). The experiment design was a randomized complete block consisting of complete fertilizer treatment-Fc (nitrogen [N], phosphorus [P], potassium [K], calcium [Ca], magnesium [Mg] and zinc [Zn]) and treatments with specific nutrient excluded from the complete fertilizer treatment (Fc-N, Fc-P, Fc-K, Fc-Ca, Fc-Mg and Fc-Zn) with four replications. Respective rates of 30 kg N ha-1, 100 kg P ha-1, 50 K kg ha-1, 50 kg Ca ha-1, 50 kg Mg ha-1 and 10 kg Zn ha-1 were applied as basal fertilizer. Rice variety WITA 12 was used and additional rate of urea was applied at 35 kg N ha-1 at rice tillering and panicle initiation stages excluding Fc-N and the control (no fertilizer). Results revealed significant (P<0.05) decreasing effect of N and Ca deficiencies on the grain yield and additional effects of K and Zn deficiencies occurring occasionally. A synergistic interaction of soil nutrients and the change of soil pH after flooding were likely to be useful tools for irrigated soil fertility management in a way of sustainable rice production in the irrigated plain of Sahel in West Africa.