Placement profond de l’urée (PPU) et amélioration de l’efficacité d’utilisation de l’azote en riziculture irriguée dans le périmètre rizicole de Karfiguela au Burkina Faso

Abstract

Objective: Tests were carried out on Karfiguela rice scheme in Burkina Faso to assess the contribution of Urea Deep Placement (UDP) in improving nitrogen efficiency in flooded rice compared to simple urea. Methodology and results: A split plot experimental design was used; the main plots were represented by the combination varieties x densities and manure plots arranged in sub-plots. Analysis of agronomic performances showed that the best yields are obtained with the UDP in plots planted at a density of 20 cm x 20 cm with FKR 19 and FKR 56N rice varieties.Analysis indices of nitrogen uptake showed a better recovery rate of nitrogen in UDP plots to the same density and strong correlation between nitrogen absorbed and yields instead of the nitrogen supply and yields. Conclusion and application: UDP present potential to improve rice productivity and fertilizer use efficiency in agro-ecological conditions of Karfiguela. For a scheme like Karfiguela where farmers usually use high transplanting density (higher than 20 x 10 cm), these results will also be a great interest to the extent that the reduction of manpower will be significantly relevant for a planting space at 20 x 20 cm. In this test conditions, soil was very poor in organic matter and nitrogen recovery rate for the best treatment was less than 20%. The observed yield could increase considerably in farmer’s field with eventual apply of manure creating physical and chemical favourable conditions for rice development. Keys words: nitrogen, urea deep placement, efficiency, simple urea, rice productivity, Burkina Faso