TITLE:
Residual Effects of Phosphate Amendments on Rainfed Rice (Oryza sativa L.) Nutrition and Soil Properties in Three Agroecological Zones of Côte d’Ivoire
AUTHORS:
Affi Jeanne Bongoua-Devisme, Wondouet Hippolyte Kpan, Pla Kouassi Adou, Franck Michaël Lemonou Bahan, Konan-Kan Hippolith Kouadio, Anselme Kan Louis Koko
KEYWORDS:
Phosphate Amendment, Moroccan Phosphate Rock, Triple Superphosphate, Yield, After-Effect, Nutrition, Crop Balance, Cote d’Ivoire
JOURNAL NAME:
Open Journal of Soil Science,
Vol.14 No.10,
October
23,
2024
ABSTRACT: A study was conducted in Côte d’Ivoire to assess the after-effect of phosphate amendments on rice yields and soil properties. Eight types of amendments, composed of Moroccan phosphate rock (PRM) and triple superphosphate were tested in three agroecological zones over three consecutive years of cultivation. This study revealed that the application of Moroccan phosphate rock (PRM) and/or triple superphosphate (TSP) did not significantly affect soil cation exchange capacity (CEC) and organic carbon (Corg) content. However, there was a negative residual effect of PRM-rich treatments on soil pH and K and N content, but the impact varies depending on the characteristics of the soils studied. Furthermore, nutrient losses, notably nitrogen from −17.5 to −267.7 kg/ha and potassium (−0.1 to 0.7 kg/ha), were observed in all treatments. Only phosphorus showed a positive balance of +49.56 to +52 kg/ha in PRM-rich treatments. Treatment T3, composed of 80% RPM and 20% TSP, was the most effective in all zones, with a relative increase in grain yields of over 100% compared to the control. These results suggest that the input of natural phosphate rock can significantly improve rice yields and soil properties in the studied agroecological zones in Côte d’Ivoire.