On‐farm Measurement of Electrical Conductivity for the Estimation of Ammonium Nitrogen Concentration in Pig Slurry

• Published in: Journal of environmental quality 2012-05, Vol.41 (3), p.893-900
• Main Authors: Yagüe, M. R., Quílez, D.
• Format: Article
• Language: English
• Subjects: Agricultural land; Agriculture; Ammonium; Animal wastes; Animals; Distilled water; Electric Conductivity; Electrochemistry - methods; Environmental risk; Farmers; Farms; Fertilizers; Nitrogen; Nitrogen - chemistry; Pig manure; Quaternary Ammonium Compounds - chemistry; Reagents; Slurries; Swine; Waste Disposal, Fluid - methods
• ISSN: 0047-2425; 1537-2537
• DOI: 10.2134/jeq2011.0352

Pig (Sus scrofa domesticus) slurry (PS) is commonly applied as fertilizer to agricultural fields. Knowledge of PS nitrogen content is essential for good management, but PS nitrogen content is highly variable, not only between farms but also within a farm. Laboratory analysis of animal slurries is often expensive and impractical for routine farmer use. Therefore, when slurry is spread on land, its fertilizer value is generally unknown, resulting in the risk of pollution. In this work, two rapid and suitable for field use methods for determining PS ammonium N (NH4+–N) concentration (Quantofix and conductimetry) are evaluated. The electrical conductivity of a dilution 1 PS:9 distilled water had better results than Quantofix, did not need reagents, and gave a direct value of NH4+–N concentrations (range, 1.0–7.6 kg NH4+–N m−3). The conductimetry method allows the use of alternative waters with EC