Resistance to perturbation in agricultural land: Can we identify and fingerprint functional soil conditions across scales?

Lead Research Organisation: NERC Centre for Ecology and Hydrology
Department Name: Soils and Land Use (Lancaster)

Abstract

Managing the land sustainably is important to nature and human wellbeing. The way that agricultural land is managed, and the plant species which are grown on it, can influence biological, physical and chemical characteristics of soil, and affect its ability to recycle nutrients, grow crops, feed grazing animals, regulate water movement and store carbon. The effects of higher management intensity over an extended period of time (e.g. continuous cropping, increased use of fertilisers, higher grazer densities) is likely to degrade soil quality and reduce its ability to sustain the various services that it provides such as food production, water and nutrient cycling. Understanding how different agricultural land management practices may impact soil conditions is therefore important so that soil quality can be maintained or improved. Poor quality soils may also be more susceptible to perturbations such as flooding and drought. Since these climatic events are becoming more frequent in the UK, it is also vital that we recognise management practices and soil conditions that confer resistance to such perturbations.
This project aims to identify the influence of plant composition, land management and soil type on soil characteristics considered as indicators of soil quality. It will use existing data from a UK-wide monitoring programme and create new data using archive soil samples to examine soil indicators (e.g. organic matter concentration) and biophysical resistance (e.g. soil aggregate stability) across the gradient from arable to semi-natural grassland management. This work will also evaluate whether combinations of soil quality indicators differ between climatic regions and soil types of the UK.

Since the measurement of soil properties with extensive sampling can often require detailed, time-consuming and expensive laboratory analyses, there has been a drive towards the development and use of proximal approaches for measuring soil properties. These approaches include the use of spectral measurements, which examine the reflectance of different wavelengths of light from soil samples, and are used to derive calibrations which can be validated and use to estimate soil properties using the spectral information. Model calibrations will be derived for three different spectral methods and digital imagery, including spatial environmental data, and the utility and predictive ability of these approaches to fingerprint soil quality indicators compared. The methods using visible spectra and digital imagery will then be applied and field-tested, across landscape gradients and in field experiments, and appraised with regard to the cost and utility for estimating soil quality indicators across scales.

This project will quantify how soil quality indicators are affected by environmental factors and how it changes across a gradient of agricultural land management, and identify conditions that determine the ability of different soils to resist and recover from perturbations. It will also test the ability of spectral measurements to fingerprint soil quality and resistance with the potential to provide a rapid evaluation of soil quality under different management practices. Overall, it will generate new scientific insight to inform the sustainable management of UK soils and provide practical tools to estimate soil functioning on agricultural land.

Planned Impact

Agricultural land management controls the delivery of functions and services provided by soils. Changes in management intensity can degrade soil quality and its multifunctional capacity. It is therefore of critical importance to broaden understanding of how different agricultural land management practices may impact soil conditions and also how changes may alter the ability of the soil to resist perturbations such as flooding and drought. The research and policy community will benefit from the scientific insight generated by the project, including improved understanding of the links between above and belowground systems under agricultural land management, and extended knowledge of the key controls on soil quality indicators. It will also leave a legacy of large-scale datasets on key soil indicators and spectral data using visible (VIS), near-infrared (NIR) and mid-infrared (MIR) approaches, linked to existing co-located environmental data, across a broad gradient of agricultural land use from arable to semi-natural grassland. These data have excellent potential for re-use and contribution to further large-scale modelling and mapping is expected. The findings from the project will impact farmers and land managers by providing spatially relevant information to help with land management decisions for sustainable soil functions under changing climate. The tools developed in the project also have the potential to provide the ability for cheaper, more rapid evaluation of soil quality under different management practices, and the ability to measure these more intensively over time. The development of a smartphone app mean that such tools could be readily adopted. Together, the findings of the project inform the sustainable management of UK soils and provide the practical tools to estimate soil functioning on agricultural land.
 
Title Agricultural topsoil NIR spectra 
Description Archive soil samples from Countryside Survey (both CS1998 and CS2007) were used to produce Near-Infrared (NIR) spectral data for arable and grassland topsoils. Soil from each sample was scanned to produce reflectance spectra covering the 350-2500 nm wavelength range. These analyses included: - CS1998; approximately 430 locations ("Core samples") across Great Britain; air-dried, 2mm sieved soil. - CS2007; approximately 430 locations ("Core samples") across Great Britain; air-dried, 2mm sieved soil. - CS2007; approximately 800 locations ("Wider samples") across Great Britain; air-dried, 2mm sieved soil. - CS2007; approximately 430 locations ("Core samples") across Great Britain; ball-milled soil. 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? No  
Impact These data have been used within the project in calibration models for predicting key soil quality indicators using spectral data. These data will be submitted in 2019 to the EIDC. 
 
Title Agricultural topsoil Visible spectra 
Description Archive soil samples from Countryside Survey (CS2007) were used to produce visible spectral data for topsoils in locations across Great Britain. Air-dried, 2mm sieved soil from each sample were scanned using a newly-developed portable and low-cost spectrometer to produce visible wavelength spectra (see Aitkenhead et al. 2018 Geoderma 313, 265-275). 
Type Of Material Database/Collection of data 
Year Produced 2018 
Provided To Others? No  
Impact The dataset has not been published yet but will initially be used within the project in models used to predict soil quality indicators using spectral data. 
 
Title Soil aggregate stability data from arable and grassland in Countryside Survey, Great Britain 2007 
Description This dataset consists of Particle Size Distribution (PSD) measurements made on 419 archived soil samples and derived aggregate stability metrics from arable and grassland habitats across Great Britain in 2007. Laser granulometry was used to measure PSD of 1-2 mm aggregates before and after sonication and the difference in their Mean Weight Diameter (MWD) used to indicate aggregate stability (=Disaggregation reduction; sensu Rawlins et al. 2015 European Journal of Soil Science 66, 604-614). The samples were collected as part of the Countryside Survey monitoring programme, a unique study or 'audit' of the natural resources of the UK's countryside. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Impact - The dataset has been used within the project in Structural equation models (SEMs) linking land management, climate and soil biology, to key soil quality indicators. - The dataset was submitted to the EIDC in February 2020 and was made available for use immediately. 
 
Title Soil mid-infrared spectroscopy data from arable and grassland in Countryside Survey, Great Britain 2007 
Description This dataset consists of mid-infrared (MIR) spectra measured on 427 archived soil samples from arable and grassland habitats across Great Britain in 2007. Data on diffuse reflectance spectra, wavenumber range 4000-400 cm-1, were obtained from subsamples of finely ground soil. The soil samples were collected as part of the Countryside Survey monitoring programme, a unique study or 'audit' of the natural resources of the UK's countryside. The analyses were conducted as part of study aiming to quantify how soil quality indicators change across a gradient of agricultural land management and to identify conditions that determine the ability of different soils to resist and recover from perturbations. 
Type Of Material Database/Collection of data 
Year Produced 2020 
Provided To Others? Yes  
Impact Data used in predictive models of soil properties and soil health indicators for UK arable and grassland. 
URL https://doi.org/10.5285/d66ca0a6-403d-4f5a-bef1-8ee177f1e1b3
 
Description Development of methods for predictive modelling of soil properties 
Organisation James Hutton Institute
Country United Kingdom 
Sector Charity/Non Profit 
PI Contribution We hold existing data and maintain soil archives from the GB Countryside Survey, and have expertise in their statistical analysis. These resources are being used to produce new data for agricultural topsoils in locations across GB and for modelling activities predicting soil properties and soil quality indicators. Collaboration includes the testing of a new visible spectrometer developed by JHI.
Collaborator Contribution JHI have constructed and provided a prototype of a new visible spectrometer (see Aitkenhead et al. 2018 Geoderma 313, 265-275), and have developed bespoke software for processing digital images and conducting Neural Network calibration models for predicting soil properties and soil quality indicators.
Impact Dataset of Agricultural topsoil Visible spectra covering GB-wide locations.
Start Year 2017
 
Description Farmer Network Engagement Workshop 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Industry/Business
Results and Impact Attended Farmer Engagement Workshop on 3 October 2019 with audience including regional farmers, land managers and conservation agencies. Presented project results on soil aggregate stability in agricultural systems and discussed implications for land management practices and sustainable soil use.
Year(s) Of Engagement Activity 2019
 
Description Myerscough College Teaching & Learning Fayre 
Form Of Engagement Activity A talk or presentation
Part Of Official Scheme? No
Geographic Reach Regional
Primary Audience Other audiences
Results and Impact Aidan Keith was invited to present at the Myerscough College Teaching & Learning Fayre (15 February 2019) for staff and students at Myerscough College to find out more about key topics and current research in soil science. Two talks were given based on project research activities: 'Soil aggregate stability: Why is it important, how can you measure it and what controls it?' and 'Using spectra and digital images to predict soil properties'. Feedback from the Myerscough staff and students indicated that talks were informative, useful for keeping up-to-date with current research, and they have stimulated greater interest in the findings of NERC Soil Security projects; plans were agreed for further talks to be given once project results have been finalised.
Year(s) Of Engagement Activity 2019
 
Description Online article for Sustainable Soils Alliance 
Form Of Engagement Activity Engagement focused website, blog or social media channel
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Policymakers/politicians
Results and Impact Article written for 'Soil Soap Box' on the Sustainable Soils Alliance website (published online on 10-03-20). This was based on outputs from the NERC Soil Security Programme workshop on "Monitoring and sensing of soil organic matter in agricultural systems of the future." we held at UKCEH Lancaster in September 2019. The workshop covered low-cost methods that allow Soil Organic Matter information to be integrated with other systems to enable monitoring for agri-environment schemes and provide opportunities for decision support for farmers and policymakers.
Year(s) Of Engagement Activity 2020
URL https://sustainablesoils.org/monitoringsoilcarbon
 
Description Soil Security Programme Outcomes Event 
Form Of Engagement Activity Participation in an activity, workshop or similar
Part Of Official Scheme? No
Geographic Reach National
Primary Audience Third sector organisations
Results and Impact Engagement with attendees during interactive poster sessions at Soil Security Programme Outcomes Event on 5 December 2019 (World Soils Day) at Royal Society, London.
Year(s) Of Engagement Activity 2019