Sorghum responses to different forms of Tilemsi rock phosphate combined with soluble fertilizers in a low-input production system in Mali

Abstract

The deficiency in bioavailable phosphorus is one of the major constraints to cereal production in Mali. The objective of this study was to assess the combined effects of Tilemsi rock phosphate (PNT) with different doses of soluble fertilizers on the solubility of rock phosphate, the agronomic performance of sorghum and the chemical properties of the soil. The study consisted of the comparison of four (4) types of fertilization at three (3) levels of variation 0 kg.ha-1; 11 kg.ha-1, and 16 kg.ha-1 of phosphorus arranged in a complete randomized block with three replicates. The combination of PNT with sulfate ammonium (NH4) 2SO4 resulted in a significant increase in grain and biomass yields during the two years of the study. The increase of the rate of phosphate rock application lead to improve the sorghum grain yield by an average of 29%. The combined application of sulfate ammonium (NH4) 2SO4 with PNT significantly increased the phosphorus uptake indices from PNT. These results show that there is a possibility of improving the productivity of sorghum in Mali with the combined use of Tilemsi rock phosphate and soluble fertilizers, particularly sulfate ammonium.