Estimation of soil properties with mid-infrared soil spectroscopy across yam production landscapes in West Africa oleh P. Baumann, J. Lee, E. Frossard, L. P. Schönholzer, L. Diby, V. K. Hgaza, V. K. Hgaza, D. I. Kiba, D. I. Kiba, A. Sila, K. Sheperd, J. Six