Assessing soil aggregate stability with mobile phones

Abstract

<p>A new methodology for the assessment of soil slaking using a mobile app named SLAKES was developed. The app uses an image recognition algorithm that measures the increasing area of soil aggregates immersed in water at regular intervals over a 10 minutes period. This method measures the kinetics of the slaking process and returns a continuous stability index from 0 (very stable) to higher numbers (higher than 7 as very unstable with 14 as a commonly observed maxima).</p><p>The methodology was originally presented in  Fajardo et al. (2016) using a dataset covering a great part of the agro-ecological variability of New South Wales (NSW), Australia. By 2020 the app is already present in 36 countries from 6 continents in its Android version (released in 2017) and the iPhone version is gradually reaching an increasing audience (released in December 2019).</p><p>This work presents a study made in a medium sized farm in New South Wales, Australia. Top-soil (0-10 cm) samples were surveyed and analysed by undergraduate students using the app. Different maps of soil aggregate stability were created showing evident aggregate stability geographical patterns at medium scale. The use of SLAKES has shown reliability compared with traditional methods as shown in third party scientific publications. The simplicity of SLAKES makes this app a simple yet powerful way to assess aggregate stability and shows great potential to be included in both citizen and open science educational programs.</p><p>Fajardo, M., McBratney, A.B., Field, D.J., Minasny, B., 2016. Soil slaking assessment using image recognition. Soil and Tillage Research 163, 119-129.</p>

Combined Use of a Bacterial Consortium and Early-Colonizing Plants as a Treatment for Soil Recovery after Fire: A Model Based on Los Guájares (Granada, Spain) Wildfire

“…To evaluate and compare the aggregation level achieved by the soils under the different treatments, a granulometric characterization and an image-based slake test (Slakes software v.BETA, University of Sydney—Australia) were performed [ 79 , 80 ]. Moreover, a visual evaluation of the soil fragments/peds was carried out at the end of the treatment (see Section 2.8 ).…”

“…To evaluate and compare the aggregation level achieved by the soils under the different treatments, a granulometric characterization and an image-based slake test (Slakes software v.BETA, University of Sydney-Australia) were performed [79,80]. Moreover, a visual evaluation of the soil fragments/peds was carried out at the end of the Thus, the conditions applied were (i) soil without treatment (control), (ii) soil treated with bacterial consortium (SynCom), (iii) soil with B. bituminosa seeds, and (iv) soil treated with bacterial consortium and B. bituminosa seeds (Cantueso Natural Seeds, Córdoba, Spain) (Figure 2c).…”

Evaluation of Aggregate Stability Using the Slaking Index Method with Soil Physical Approach in Keduang Sub-Watershed, Indonesia

“…(3) the soil samples in the first petri dish were transferred to the second petri dish in a spread out position (not stuck together); (4) then press the "start" button on the SLAKES application and wait for processing for 10 minutes, then the slaking index value will be displayed on the smartphone application screen (Fajardo and McBratney, 2019). The slaking index obtained from analysis using the SLAKES application was input and then mapped using ArcGIS 10.4 software.…”

A high throughput approach for measuring soil slaking index

“…Image analysis is used to compute the change in projected area of each aggregate in comparison to a dry reference image. The method was implemented in the user‐friendly mobile application SLAKES in 2019, which was renamed Moulder in 2023 (Fajardo & McBratney, 2023). The Soil Health Institute (SHI) also recently developed a version of the application, called Slakes (Soil Health Institute Staff, 2023), which implements algorithms from the “SlakeItEasy” R package (Looker, 2023).…”