Correlations of Soil Fungi, Soil Structure and Tree Vigour on an Apple Orchard with Replant Soil

Abstract

The soil-borne apple replant disease (ARD) is caused by biotic agents and affected by abiotic properties. There is evidence for the interrelation of the soil fungal population and soil aggregate structure. The aim of this study conducted between March and October 2020 on an orchard in north-east Germany was to detect the correlations of soil fungal density, soil structure and tree vigour under replant conditions in a series of time intervals. By using the replant system as the subject matter of investigation, we found that replanting had an impact on the increase of soil fungal DNA, which correlated with a mass decrease of large macro-aggregates and an increase of small macro- and large micro-aggregates in the late summer. Increased proportions of water-stable aggregates (WS) with binding forces ≤ 50 J mL−1, decreased proportions of WS > 100 J mL−1 and a decrease of the mean weight diameter of aggregates (MWD) emphasised a reduction of aggregate stability in replant soils. Correlation analyses highlighted interactions between replant-sensitive soil fungi (Alternaria-group), the loss of soil structure and suppressed tree vigour, which become obvious only at specific time intervals.

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

“…They are involved in the formation and stabilization of soil aggregates (mainly macroaggregates) and therefore play a central role in the processes of soil structure formation. The stabilization of soil aggregates by fungi varies depending on the species and the nature of the available substrates and the soil cultivation method [77,78]. Ma et al [79] believe that the specific extracellular enzymes of fungi make them more effective in degrading plant residues in the soil than bacteria.…”

Assessment of Agro-Ecological Apple Replant Disease (ARD) Management Strategies: Organic Fertilisation and Inoculation with Mycorrhizal Fungi and Bacteria

“…Furthermore, it is reported to influence soil aggregation processes [36]. Soil aggregation processes are altered under replant conditions resulting in an aggregate disintegration and reduction of aggregate stability [37]. The mitigation of the ARD impact was observed by AMFbac treatment, however, was not observed when microbial inoculants were applied as single inoculum.…”

Aplicación de técnicas moleculares en microbiología del suelo para la identificación de bacterias con potencial agrícola: una revisión y análisis bibliométrico

“…In addition, the microorganisms that inhabit the soil have an incidence in the formation and stabilization of aggregates, due to this, this type of organisms are related to the processes of soil construction (Cavael et al, 2020). Soil bacteria contribute to the decomposition of plant and animal residues to form compost, which improves soil structure, lead ing to the retention of nutrients and moisture, considered important factors in sustainable agricul ture (Tanya and Leiva-Mora, 2019).…”