Integrated Management of Fertilizers, Weed and Rice Genotypes Can Improve Rice Productivity

The influence of weed control on fertilizer nitrogen use efficiencies (NUEs) by rice genotypes was studied in the Senegal River valley of West Africa with a field experiment during four rice growing seasons. It was hypothesized that integrated management of technologies could improve rice productivity. The objective was to develop integrated high-return technologies that improve irrigated rice-based systems productivity and profitability. Data indicated that rice grain yields were affected by N fertilizer, genotypes and plant densities. In good weed control conditions, optimum doses of recommended N fertilizer varied from 80 to 180 kg N ha–1. Fertilizer N use efficiencies by genotypes were affected by weed control. Profitable management options of genotypes and N fertilizer recommendations have been identified. With a good control of weed, varieties and N fertilizer recommendations were suggested as integrated management options for farmers. But poor control of weed increased N lost, decreased grain yields and profitability. Two genotypes (WAS 55-B-B-2-1-2-5 and WAS 191-1-1-7 FKR) were found to be most competitive against weeds. However, no more than 60 kg N ha–1 should ever be recommended when weeds are poorly controlled. It was concluded that productivity and profitability of irrigated rice-based systems could be improved with integrated management options of genotypes, fertilizers and weed.