Easy soil testing at a South African fertilizer manufacturer

Importance of the topic

Soil testing is a cornerstone of agronomic decision-making because it directly informs fertilizer recommendations that affect crop yield, input efficiency, farm profitability, and environmental risk. Reliable, high‑throughput laboratory analysis that complies with quality standards (ISO 17025) is essential for fertilizer manufacturers and advisory services that support large farming operations and cooperatives. Efficient and robust analytical workflows enable timely, actionable results during critical seasonal windows when sample volumes peak.

Objectives and overview of the case study

This case study describes how Omnia Fertilizer, a major South African fertilizer manufacturer and agronomic advisor, modernized soil testing in its R&D laboratory to handle seasonal workloads (~4,000 samples per day) while meeting ISO 17025 quality requirements. The laboratory moved from a Segmented Flow Analyzer (SFA) to a Thermo Scientific Gallery discrete analyzer to reduce operator dependency, lower maintenance, improve throughput and repeatability, and simplify LIMS integration. The laboratory also plans to validate additional soil tests such as total nitrogen and Mehlich III phosphorus.

Methodology

The R&D laboratory historically ran Bray I soil extract determinations on a Segmented Flow Analyzer, operating continuously in four shifts to meet seasonal demand. Challenges included high maintenance rates, need for specialist operators, and time-consuming troubleshooting. The lab introduced an automated discrete analyzer (Gallery) and compared performance on routine soil analyses, assessing ease of use, maintenance burden, repeatability, throughput, and compatibility with their Laboratory Information Management System (LIMS). All operations and validations were conducted under ISO 17025 guidance to ensure traceability, method competence, and quality control.

Used instrumentation

• Segmented Flow Analyzer (SFA) — previous method for soil Bray I extracts; required specialist operation and frequent maintenance.
• Thermo Scientific Gallery discrete analyzer — automated discrete photometric platform adopted by Omnia to replace SFA for routine soil testing.
• LIMS interface — integrated with the Gallery analyzer to capture data and streamline laboratory workflows under ISO 17025 procedures.

Main results and discussion

The laboratory reported several practical improvements after adopting the discrete analyzer:

• Operator accessibility: Four staff members could be trained to run the Gallery, removing dependency on highly specialized operators required for SFA operation.
• Reduced maintenance: Routine upkeep was substantially lower compared with the older SFA method, decreasing instrument downtime and service burden.
• Improved repeatability: Tests run on the Gallery demonstrated good repeatability suitable for routine soil diagnostics and product development studies.
• Easier LIMS integration: Data transfer and workflow automation into the laboratory information management system were simplified relative to the SFA platform.
• Operational efficiency: The discrete analyzer supported continuous operation across shifts and helped the lab manage peak seasonal sample loads more effectively.

Additionally, Omnia identified expansion of their validated test menu — specifically total nitrogen and Mehlich III phosphorus — as key next steps. The Mehlich III extraction selectively estimates plant‑available phosphorus (and potentially potassium and other nutrients) for acid to neutral soils and is important for agronomic recommendations because it correlates chemically extractable P with plant uptake.

Benefits and practical applications

The transition to discrete analysis provided several tangible benefits relevant to industrial and QA/QC laboratories:

• Scalability: Better handling of high daily sample loads during seasonal peaks without proportionate increases in specialized staffing.
• Quality and compliance: Enhanced repeatability and simplified LIMS connectivity support ISO 17025 requirements for traceability and documented methods.
• Cost and downtime reduction: Lower maintenance needs reduce direct service costs and avoid production delays in testing pipelines.
• Faster turnaround: Streamlined operations and automation shorten result delivery times, improving agronomic advisory responsiveness.
• Method expansion: Capacity for validating additional agronomically relevant tests (e.g., Mehlich III P, total N) broadens the laboratory’s diagnostic portfolio.

Future trends and potential applications

Trends likely to influence soil testing in similar industrial and commercial settings include:

• Further automation and modular discrete platforms enabling multiplexed assays and higher throughput with lower operator skill requirements.
• Tighter integration between analyzers and LIMS for real‑time data QC, electronic reporting, and laboratory workflow optimization.
• Method harmonization and validation efforts (e.g., broader adoption of Mehlich III or other regional extractants) to provide internationally comparable, agronomically meaningful results.
• At‑line and field deployable analytics for more rapid decision cycles on farms, complemented by centralized lab confirmation for regulatory and product development work.
• Data analytics and digital agronomy services that combine soil test results with crop models, remote sensing, and recommendations to optimize fertilizer use and reduce environmental impact.

Conclusion

Omnia Fertilizer’s case illustrates how migrating from segmented flow to modern discrete analysis can deliver operational resilience, improved data quality, and reduced maintenance burden while meeting ISO 17025 requirements. The practical gains — including expanded testing capacity, easier LIMS integration, and more staff‑flexible operations — support both commercial laboratory efficiency and better agronomic advice for clients. Validating additional soil tests such as total nitrogen and Mehlich III phosphorus will further enhance the laboratory’s capability to provide actionable, plant‑available nutrient assessments.

Reference

Case study: Omnia Fertilizer — Thermo Fisher Scientific discrete analysis application note, 2018.