Arbuscular Mycorrhizal Fungi Enhance P Uptake and Use Efficiency of Wheat (Triticum aestivum L.) in Ferralsols: A Study at Uasin Gishu County, Kenya

Abstract

Deficiency of macro and micronutrients is a major challenge to sustainable wheat production. Integrating biostimulants such as Arbuscular Mycorrhizal Fungi (AMF) and inorganic fertilisers has been shown to enhance wheat production by optimising their mutual benefits. However, integration of AMF and micronutrients has not been prioritised, especially in low-input systems. Thus, a two-season field study was conducted at the University of Eldoret farm, Uasin Gishu County, Kenya, to evaluate the integrated effect of AMF concoctions with phosphorus (P) and copper (Cu) fertilisers on nutrient uptake, use efficiency, and productivity in wheat. The different levels of P, Cu, and AMF were combined. The treatments were laid out in a Randomised Complete Block Design (RCBD) and replicated three times. Two levels of AMF (0 and 60 L 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: 0 kg, 5 kg, and 10 kg ha-1. Generalised linear models (GLM) were used to test the effects of AMF and fertiliser type on soil chemical properties and crop performance indices. Two- and three-way interactions between the three factors were also tested. Results show that AMF did not have significant impact on soil available P, while 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 increased P and Cu use efficiency 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 L 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 P fertilisers while increasing wheat grain yield. This study recommends co-application of 60 L AMF and 8.8 kg P ha-1 for improving P nutrition and grain yield in wheat.