Effects of agricultural management practices on earthworm populations and crop yield: validation and application of a mechanistic modelling approach

TY - JOUR

T1 - Effects of agricultural management practices on earthworm populations and crop yield

T2 - validation and application of a mechanistic modelling approach

AU - Johnston, A.S.A.

AU - Sibly, Richard

AU - Hodson, Mark Edward

AU - Alvarez, T

AU - Thorbek, Pernille

N1 - © The Authors and British Ecological Society 2015. This is an author produced version of a paper accepted for publication in Journal of Applied Ecology. Uploaded in accordance with the publisher's self-archiving policy.

PY - 2015/10/1

Y1 - 2015/10/1

N2 - 1. There is little consensus on how agriculture will meet future food demands sustainably. Soils and their biota play a crucial role by mediating ecosystem services that support agricultural productivity. However, a multitude of site-specific environmental factors and management practices interact to affect the ability of soil biota to perform vital functions, confounding the interpretation of results from experimental approaches. Insights can be gained through models which integrate the physiological, biological and ecological mechanisms underpinning soil functions. 2. We present a powerful modelling approach for predicting how agricultural management practices (pesticide applications and tillage practices) affect soil functioning through earthworm populations. By combining energy budgets and individual-based simulation models, and integrating key behavioural and ecological drivers, we accurately predict population responses to pesticide applications in different climatic conditions. 3. We use the model to analyse the ecological consequences of different weed management practices. Our results demonstrate that an important link between agricultural management (herbicide applications and zero, reduced and conventional tillage) and earthworms is the maintenance of soil organic matter (SOM). 4. We show how zero and reduced tillage practices can increase crop yields while preserving natural ecosystem functions. This demonstrates how management practices which aim to sustain agricultural productivity should account for their effects on earthworm populations, as their proliferation stimulates agricultural productivity. 5. Synthesis and Applications. Our results indicate that weed management that relies on tillage has longer term effects on soil biota than pesticide control, if the herbicides have short dissipation times. If pesticides known to be toxic to earthworms are applied, the risk of exposure will be reduced if irrigation is stopped around application time or if application is carried out during dry periods. Similarly, if the organic content of the soil is increased the recovery rate of earthworm populations can be increased. However, effects are not necessarily additive and the impact of different growing practices on earthworms will depend on their timing and the environmental conditions. Our model can be used to estimate the overall impact of different combinations of crop management activities in different regions to explore how earthworm populations respond. If our models are linked to crop yield models the costs and benefits of different crop solutions for both yields and biota could be estimated and aid optimisation of the trade-off between different ecosystem services

AB - 1. There is little consensus on how agriculture will meet future food demands sustainably. Soils and their biota play a crucial role by mediating ecosystem services that support agricultural productivity. However, a multitude of site-specific environmental factors and management practices interact to affect the ability of soil biota to perform vital functions, confounding the interpretation of results from experimental approaches. Insights can be gained through models which integrate the physiological, biological and ecological mechanisms underpinning soil functions. 2. We present a powerful modelling approach for predicting how agricultural management practices (pesticide applications and tillage practices) affect soil functioning through earthworm populations. By combining energy budgets and individual-based simulation models, and integrating key behavioural and ecological drivers, we accurately predict population responses to pesticide applications in different climatic conditions. 3. We use the model to analyse the ecological consequences of different weed management practices. Our results demonstrate that an important link between agricultural management (herbicide applications and zero, reduced and conventional tillage) and earthworms is the maintenance of soil organic matter (SOM). 4. We show how zero and reduced tillage practices can increase crop yields while preserving natural ecosystem functions. This demonstrates how management practices which aim to sustain agricultural productivity should account for their effects on earthworm populations, as their proliferation stimulates agricultural productivity. 5. Synthesis and Applications. Our results indicate that weed management that relies on tillage has longer term effects on soil biota than pesticide control, if the herbicides have short dissipation times. If pesticides known to be toxic to earthworms are applied, the risk of exposure will be reduced if irrigation is stopped around application time or if application is carried out during dry periods. Similarly, if the organic content of the soil is increased the recovery rate of earthworm populations can be increased. However, effects are not necessarily additive and the impact of different growing practices on earthworms will depend on their timing and the environmental conditions. Our model can be used to estimate the overall impact of different combinations of crop management activities in different regions to explore how earthworm populations respond. If our models are linked to crop yield models the costs and benefits of different crop solutions for both yields and biota could be estimated and aid optimisation of the trade-off between different ecosystem services

KW - agriculture

KW - earthworm

KW - ecosystem serivces

KW - energy budget

KW - pesticide

KW - population modelling

KW - tillage

KW - weed management

U2 - 10.1111/1365-2664.12501

DO - 10.1111/1365-2664.12501

M3 - Article

SN - 0021-8901

VL - 52

SP - 1334

EP - 1342

JO - Journal of Applied Ecology

JF - Journal of Applied Ecology

IS - 5

ER -