TITLE:
Decoupling between Arbuscular Mycorrhizal Fungal Root Colonization and Early Rice Growth Responses in a Low-Phosphorus Sahelian Substrate: A Greenhouse Proof-of-Concept Study
AUTHORS:
Madina Alima Tapsoba, Hadou Haro, Abdel Aziz Ben Yaya Zoungrana, Mahamadi Dianda
KEYWORDS:
Arbuscular Mycorrhizal Fungi, Native Inoculum, Compost, Rice Early Growth, Root Colonization
JOURNAL NAME:
American Journal of Plant Sciences,
Vol.17 No.11,
November
10,
2026
ABSTRACT: Rice cultivation in Sahelian countries requires fertility-management strategies that improve early crop growth while reducing reliance on mineral fertilizers alone. Arbuscular mycorrhizal fungi (AMF) can contribute to plant nutrition under phosphorus-deficient conditions, but plant responses depend on the fertility context in which root colonization occurs. This greenhouse proof-of-concept study evaluated whether a mixed native AMF inoculum, applied alone or in combination with compost or reduced NPK/urea fertilization, was associated with differences in AMF root colonization and early vegetative performance in rice (Oryza sativa L., cv. FKR64). Six treatments were compared in a completely randomized design with nine replicates: 100% AMF, 100% compost, AMF + 100% compost, AMF + 50% compost, AMF + 50% NPK/urea, and an uninoculated, unfertilized control. Plant height, tiller number, aboveground dry biomass, root dry biomass, and mycorrhizal frequency and intensity were measured over a 56-day period. Treatment profiles were analyzed using principal component analysis and hierarchical clustering. Inoculated treatments generally showed greater root colonization than the control. The highest colonization frequency and intensity were observed in the AMF + 50% NPK/urea treatment, but its mean growth responses were comparatively low. Significant pairwise growth differences depended on the variable and comparator. Treatments containing compost generally exhibited the most favorable early growth profiles. The AMF + 50% compost combination produced the tallest plants at 56 days, whereas the 100% compost and AMF + 100% compost treatments showed more favorable biomass or tillering responses, depending on the variable considered. This study should be interpreted as a greenhouse proof-of-concept that identifies promising treatment contrasts for future field validation rather than as a direct agronomic recommendation. Field validation, compost characterization, explicit nutrient-balance assessment, and direct measurements of nutrient uptake are required before AMF-compost strategies can be recommended for rice production.