Soil fungal community structure and seasonal diversity following application of organic amendments of different quality under maize cropping in Zimbabwe

Abstract

Recent advocacy for Integrated Soil Fertility Management (ISFM) in smallholder farming systems in east and southern Africa show substantial evidence of increased and sustained crop yields associated with enhanced soil productivity. However, the impact ISFM on soil fungi has received limited attention, yet fungi play key roles in crop growth. Following total soil DNA extraction with ZR soil microbe miniprep kit, illumina sequencing was used to, examine the fungal communities (ITS1F) under a maize crop following co-application of organic nutrient resources including Crotalaria juncea, cattle manure and maize stover with inorganic fertilizers at three-time periods (T1-December, T2-January, and T3-February) in Zimbabwe. Ninety-five fungal species were identified that were assigned to Ascomycota (>90%), Basidiomycota (7%) and Zygomycota (1%). At T1, Ascomycota and Basidiomycota were identified across treatments, with Ascomycota attaining > 93% frequency. Fungal succession was noted and involved reduction of Ascomycota coupled by increase in Basidiomycota under the different treatments. For example at T3, Basidiomycota increased to 34% while Ascomycota declined to 66% under manure but remained unchanged in other two organics. Pre-season mineral nitrogen (N) associated with the ‘Birch effect’ apparently influenced the fungal community structure at T1 while readily available fertilizer N was critical at T2 and T3. The low-quality maize stover promoted the presence of Exophiala sp SST 2011 and this was linked to N immobilization. The impact of N addition was more pronounced under medium (manure) to low-quality (maize stover) resources. Fungi required phosphorus (P) and N for survival while their proliferation was dependent on substrate availability linked to resource quality. Interactive-forward test indicated that soil available P and N were most influential (P < 0.05) factors shaping fungal communities. Co-application of medium to high quality organic and inorganic resources show promise as a sustainable entry point towards enhancing belowground fungal diversity critical in driving nutrient supply.

Effect of Previous Crop on the Structure of Bacterial and Fungal Communities during the Growth of Vicia faba L. spp. minor

“…The number of fungi belonging to Ascomycota may decrease as the organic matter in the soil is degraded. Other fungi, for example, Mortierellomycota or Basidiomycota, may take up these organics for growth, resulting in nutrient depletion and the inhibition of Ascomycota growth [87]. In addition, our study showed that spring wheat and spring rapeseed used as the previous crops positively affected the development of the Mortierella genus fungi, winter wheat positively affected the development of Cladosporium fungi, and maize positively affected the development of Alternaria fungi.…”

Seasonal variation in the soil fungal community structure of Larix gmelinii forests in Northeast China

“… Xie and Yin (2022) showed that soil fungal diversity and richness in broad-leaved forests were higher than those in conifer forests. Fungal community diversity and composition are significantly driven by soil pH, available nitrogen, available phosphorus, moisture, organic carbon, fine root biomass and root tissue density ( Beauregard et al, 2010 ; Zhou et al, 2016b ; Tauro et al, 2021 ). Soil pH is the dominant driver that is significantly related to fungal alpha diversity ( Wang et al, 2015 ; Adamo et al, 2021 ).…”

“…SOC may affect the structure of the soil fungal community ( Sul et al, 2013 ; Li et al, 2017 ), because the abundance of cellulose-degrading fungi may be linked to SOC fractions and may respond to changes in SOC fractions differently. Soil available phosphorus and nitrogen are influential factors shaping fungal communities ( Tauro et al, 2021 ). In a previous study, the fungal community was less strongly affected by pH, because fungi generally exhibit wide pH ranges for optimal growth ( Rousk et al, 2010 ; Wang et al, 2015 ).…”

Seasonal patterns of rhizosphere microorganisms suggest carbohydrate-degrading and nitrogen-fixing microbes contribute to the attribute of full-year shooting in woody bamboo Cephalostachyum pingbianense

“…The PCR reaction system (20 μL) for bacteria included 4 μL of 5 × FastPfu buffer, 2 μL of 2.5 mM dNTPs, 0.8 μL of each primer (5 μM), 0.4 μL of TransStart FastPfu DNA Polymerase (TransGen, Beijing, China), 0.2 μL of BSA and 10 ng of Template DNA. Meanwhile, to identify the characteristics of fungal communities, the internal transcribed spacer 1 (ITS1) region of the ribosomal RNA gene was amplified using primers ITS1F (5′-CTTGGTCATTTAGAGGAAGTAA-3′) and ITS2R (5′-GCTGCGTTCTTCATCGATGC-3′) ( Tauro et al, 2021 ). The PCR reaction system (20 μL) for fungi included 2 μL of 10 × buffer, 2 μL of 2.5 mM dNTPs, 0.8 μL of each primer (5 μM), 0.2 μL of TaKaRa rTaq DNA Polymerase (Takara, Shiga, Japan), 0.2 μL of BSA and 10 ng of Template DNA.…”