Contrasting Management Techniques and Soil Types Affect Network Connections between Soil Properties and the Tulip Microbiome

Conventional agriculture relies on high inputs of chemical fertilisers and pesticides, leading to extensive soil damage. As a result, there has been a shift towards organic cultivation to ameliorate these negative effects. However, knowledge gaps remain concerning how different agricultural management regimes can alter soil properties, root-associated biota and relationships between them. We sampled soils and bulbs from clay and sand tulip fields with conventional, organic and hybrid (i.e., intermediate between conventional and organic) management regimes to determine effects on abiotic and biotic soil properties, tulip bulb microbiomes/biota and network connectivity between them. We found that soil abiotic properties were not driven by management. However, soil microbial community composition was determined by interactions between soil type and management. Specifically, conventional management created more heterogeneous and homogenous bacterial and fungal soil communities, respectively, across soil types, while organic and hybrid soil communities differed between soil types. A partial least squares path model revealed that across all fields, soil properties determined the composition of tulip bulb biota (i.e., microorganisms, nematodes), while management techniques did not play a significant role, neither directly nor indirectly. Network analyses revealed more modular (i.e., independent) nodes of association in fields with sandy soils. Specifically, management techniques (i.e., chemical usage, ploughing depth, diminished crop rotation) formed a cluster that was independent from most soil (abiotic and biotic) and bulb biotic properties, while clay field networks showed the opposite. Our results indicate that conventional agriculture can homogenise soil microbial communities, with potential impacts on soil function and buffering capacity to stress. Increased modularity between soil properties, management techniques and tulip bulb biota in sand fields could mean increased resistance to disturbance and abiotic and biotic stress as a result of higher functional redundancy. Interactions between agricultural management regime and soil type must be taken into consideration when determining long-term influences on crop microbiome/biota associations and the potential effects on soil health and productivity

Green Challenges: Bestrijding van Meloidogyne spp. (wortelknobbelaaltjes) in chrysant metbiologische bestrijdingsmiddelen en biostimulanten

Root-knot nematodes (Meloidogyne spp.) are a worldwide problem in many crops. These nematodes are a particular problem in glasshouse-grown chrysanthemums. In order to combat root-knot nematodes in the glasshouse, the soil is typically steamed every 5-6 growth cycles. However, this method is expensive, environmentally unfriendly and reduces the resistance and resilience of the soil against other pathogens and pests. In this experiment we added different biological pesticides and basic substances and biostimulants both individually and in combination in order to determine if there is an interactive or additive effect against damage caused by root-knot nematodes in chrysanthemums. We found that the use of the biological pesticide derived from garlic extract and the basic substance chitosan HCl and biostimulants comprised of sea minerals and plant oils reduced the damage to chrysanthemum caused by root-knot nematodes. A number of the treatments caused a reduction in plant biomass (e.g., soldier fly waste products and their interaction with chitosan HCl and interactions between the chemical nematicide oxamyl and several of the biostimulants). However, this reduction was minimal

Beheer beïnvloedt relaties tussen bodemeigenschappen en het tulpenmicrobioom

Conventional agriculture relies on high inputs of chemical fertilisers and pesticides, leading to extensive damage to the soil. There has been a shift towards organic cultivation to ameliorate these negative effects. However, many knowledge gaps remain. We sampled soils and bulbs from tulip fields with conventional, organic and hybrid (i.e., combination between conventional and organic) management regimes to determine effects on abiotic and biotic soil properties, tulip bulb microbiomes/biota and network connectivity between them. We found that many biotic properties were driven by management and microbial community composition was determined by an interaction between soil texture and management. Specifically, conventional management created heterogeneous bacterial and homogenous fungal soil communities across soils types. Network analyses revealed more independent nodes of association in sand fields, with detrimental management techniques isolated from interactions with most soil (abiotic and biotic) and bulb biotic properties, while clay field networks showed the opposite. Our results indicate that conventional management can have a homogenizing effect on soil microbial communities, with potential impacts on soil function and buffering capacity to stress. Increased modularity between soil properties, management techniques and tulip bulb biota in sand fields could mean increased resistance to disturbance and stress

Contrasting Management Techniques and Soil Types Affect Network Connections between Soil Properties and the Tulip Microbiome

Conventional agriculture relies on high inputs of chemical fertilisers and pesticides, leading to extensive soil damage. As a result, there has been a shift towards organic cultivation to ameliorate these negative effects. However, knowledge gaps remain concerning how different agricultural management regimes can alter soil properties, root-associated biota and relationships between them. We sampled soils and bulbs from clay and sand tulip fields with conventional, organic and hybrid (i.e., intermediate between conventional and organic) management regimes to determine effects on abiotic and biotic soil properties, tulip bulb microbiomes/biota and network connectivity between them. We found that soil abiotic properties were not driven by management. However, soil microbial community composition was determined by interactions between soil type and management. Specifically, conventional management created more heterogeneous and homogenous bacterial and fungal soil communities, respectively, across soil types, while organic and hybrid soil communities differed between soil types. A partial least squares path model revealed that across all fields, soil properties determined the composition of tulip bulb biota (i.e., microorganisms, nematodes), while management techniques did not play a significant role, neither directly nor indirectly. Network analyses revealed more modular (i.e., independent) nodes of association in fields with sandy soils. Specifically, management techniques (i.e., chemical usage, ploughing depth, diminished crop rotation) formed a cluster that was independent from most soil (abiotic and biotic) and bulb biotic properties, while clay field networks showed the opposite. Our results indicate that conventional agriculture can homogenise soil microbial communities, with potential impacts on soil function and buffering capacity to stress. Increased modularity between soil properties, management techniques and tulip bulb biota in sand fields could mean increased resistance to disturbance and abiotic and biotic stress as a result of higher functional redundancy. Interactions between agricultural management regime and soil type must be taken into consideration when determining long-term influences on crop microbiome/biota associations and the potential effects on soil health and productivity