EFFICIENCY OF ARBUSCULAR MYCORRHIZAL FUNGI IN ENHANCING PHOSPHORUS AND COPPER UTILIZATION IN WHEAT GROWN IN FERRALSOLS OF UASIN GISHU COUNTY, KENYA

Abstract

Declining soil fertility characterized by deficiency of both macro and micronutrients is a major challenge to sustainable wheat production. Integrating bio-stimulants such as Arbuscular Mycorrhizal Fungi (AMF) with inorganic fertilizers has been shown to have the potential to enhance wheat production by optimizing their mutual benefits. However, a combination of AMF and micronutrients has not been given the necessary attention, especially in low-input systems such as those dominant in sub-Saharan Africa. Thus, the current study was conducted in Uasin Gishu County, Kenya, for two seasons to evaluate the effect of integrating AMF with phosphorus (P) and copper (Cu) fertilizers on wheat grain yield, nutrient uptake, and use efficiency. Two levels of AMF (0 and 60 kg ha -1 ) were applied with three levels of P: 0 kg, 8.8 kg, and 17.6 kg ha -1 , and three levels of Cu at 0 kg, 5 kg, and 10 kg ha -1 . The experiment was conducted in an RCBD, and fertilizer treatments were applied in a factorial arrangement in the 2018 and 2019 long rains seasons. Results showed that while AMF did not have a significant impact on soil available P, available Cu increased by 32% - 40% compared to the control. AMF also enhanced P and Cu uptake by 27 - 30% and 24 - 38%, respectively. Furthermore, AMF boosted P and Cu uptake efficiency by 30 - 35% and 25 - 40%, respectively, whereas P and Cu use efficiency increased by about 15 - 31% and 18 - 35% above the plots without AMF, respectively. Co-application of P at 8.8 kg ha -1 and 60 kg AMF ha -1 recorded the highest wheat grain yield of 2.84 and 4.72 Mg ha -1 during the 2018 and 2019 long rain seasons, respectively. The study shows that the use of AMF could play a significant role in reducing the amount of inorganic fertilizers, which cuts down the cost of production to most smallholder farmers, but at the same time enhancing nutrient uptake and use efficiencies, and thus grain yield. This study recommends co-application of 60 kg ha -1 of AMF and 8.8 kg P ha -1 for optimal wheat yield and P nutrition in wheat.