Arbuscular mycorrhizal fungi reduce lodging of teff [<i>Eragrostis tef</i> (Zucc.) Trotter] under N fertilizer applications

Lodging in teff reduces yield, and applying nitrogen fertilizer worsens its impact. This study assesses the combined effects of arbuscular mycorrhizal fungi (AMF) and N fertilizer on lodging and yield in teff. The study, conducted in two districts over two consecutive years, included two AMF conditions (inoculated and non-inoculated) and five levels of N (0, 46, 92, 138, and 184 kg/ha). Plant height, panicle length, total number of tillers, lodging index, shoot biomass yield, grain yield, harvest index, nitrogen uptake, phosphorus uptake, and silicon uptake were significantly influenced by AMF, N levels, and their interactions. Inoculation with AMF increased plant height by 59.87%, panicle length by 18.20%, total number of tillers by 87.13%, shoot biomass yield by 30.14%, grain yield by 37.60%, harvest index by 10.71, N uptake by 112%, phosphorous uptake by 86%, and silicon uptake by 104% and reduced lodging by 229.63% compared to the non-inoculated controls. Inoculation with AMF conferred two benefits to the plants. First, inoculated plants lodged less frequently. Secondly, their lodging remained stable even with increasing nitrogen application. In contrast, non-inoculated groups not only lodged more frequently, but this lodging was exacerbated by higher nitrogen concentrations. Lodging index was significantly negatively correlated with nitrogen, silicon, and phosphorus uptake in the shoots, suggesting that AMF-inoculated plants do not lodge even at higher nitrogen levels, which may help prevent yield loss from nitrogen application. The higher yields demonstrated by AMF-inoculated groups may result from AMF’s ability to mitigate nitrogen-induced lodging.