TITLE:
Calcium-Magnesium Ca/Mg Ratios and Their Agronomic Implications for the Optimization of Phosphate Fertilization in Rainfed Rice Farming on Acidic Ferralsol in the Forest Zone of Ivory Coast
AUTHORS:
Fernand G. Yao, Brahima Kone, Franck M. L. Bahan, Kouadio Amani, Jean L. Essehi, Mamadou B. Ouattara, Konan E. B. Dibi, Brou Kouame, François Lompo, Albert Yao-Kouame
KEYWORDS:
Soil Acidity, Ca/Mg Ratios, Phosphate Fertilization, Rice Growing, Ivory Coast
JOURNAL NAME:
Open Journal of Soil Science,
Vol.14 No.1,
January
24,
2024
ABSTRACT: This
study is a contribution to improving rice productivity on acidic plateau soils
of the tropical rainforest zone. It is based on taking into account the
cationic balances of the soil in order to optimize the phosphorus (P) nutrition
of rice on these acidic soils, where this nutrient constitutes a limiting
factor for agricultural production. Three (3) pot trials were conducted in
Adiopodoumé in the forested south of Côte d’Ivoire. The interactive effects of
calcium carbonate (0, 25, 50 and 75 kg Ca ha−1) and magnesium
sulfate (0, 25, 50 and 75 kg Mg ha−1) were evaluated on the response
of NERICA 5 rice at doses 0, 25, 50 and 75 kg P ha−1 of natural
phosphate from Togo, applied only once at the start of the experiment.
Additional fertilizers of nitrogen (N) (100 kg N ha−1) and potassium
(K) (50 kg KCl ha−1) were added to each of the tests in a split-plot
device. The test results revealed a paddy production potential of approximately
3 to 5 t⋅ha−1 for NERICA 5 on an acidic soil, under the effect of
the interaction of P, Ca and Mg. The quadratic response of rice yield to the
doses of these fertilizers would be more dependent on their balance, itself
influenced by Ca nutrition. For the sustainability and maintenance of rice
production in agro-ecology studied, it was recommended doses of 38 kg Ca ha−1,
34 kg Mg ha−1 in a Ca/Mg ratio (1/1) with intakes of 41 kg P ha−1,
overall in a ratio 1/1/1 (P/Ca/Mg) more favorable to the availability of free
iron considered a guiding element of mineral nutrition. Thus, these promising
results should be confirmed in a real environment for better management of the
fertilization of rice cultivated on acidic plateau soils in Côte d’Ivoire.