Performance of maize (Zea mays L.) cultivars and community structure of Arbuscular Mycorrhizal Fungi in response to tillage practices and soil amendments in a derived Savanna

摘要

Article Details: Received: 2019-07-11 Accepted: 2019-10-03 Available online: 2019-12-31 https://doi.org/10.15414/afz.2019.22.04.114-123 Arbuscular mycorrhizal fungi (AMF) are often negatively affected in agro-systems. This investigation tested the hypothesis that community structure of AMF would vary in soil sown with maize (Zea mays L.) and amended with inorganic NPK fertilizer and tillage practice; that varietal variation of maize would have implication on their performance in a derived savanna. Field experiments were conducted at the Teaching and Research Farm, Federal University of Agriculture, Abeokuta in the early and late cropping seasons of 2013. Three tillage practices [conventional (CT), minimum (MT) and zero (NT)] were imposed on maize cultivars (Oba super 2 and Swan 1) in soil amended with NPK fertilizer (120 kg N/ha + 60 kg P2 O5 /ha + 60 kg K2 O/ha) and no fertilization. The treatments were in split-split arrangement fitted into randomized complete block design, replicated thrice. The main plot consisted of tillage practises, the sub plot consisted of maize varieties, while the sub-sub plot was made of soil amendments. Glomus was identified in the soil in the order NT MT CT (early and late seasons of 2013). Similar pattern was observed on specie richness (late season), specie evenness and diversity (both seasons). Spore count, percentage AMF colonization, specie richness, evenness and diversity were significantly higher in non-amended soil than amended. Significantly higher spore count was observed in the rhizosphere of Oba super 2 than Swan 1. Conversely more Acaulospora was observed in Swan 1 than Oba super 2. These evidences suggested that NT supported enriched community structure of AMF with a predominance of Glomus. Conversely, amending soil with NPK in this agroecology reversed this pattern, except for Glomus. Improved performance of maize in amended soil could have implied complimentary role of Glomus apart from nutritional. Cultivar differences of maize and seasons could have explained variation in species diversity of AMF in a derived savanna.