Slurry samples were filtered and the N[H.sub.4.sup.+]-N and N[O.sub.3.sup.-]-N content of the filtrate determined by continuous flow analysis on a TrAAcs
Samples were also analyzed with a TRAACS
800 Auto-Analyzer (Brant Luebbe, Buffalo Grove, IL) for total Kjeldahl N.
N[H.sub.4]-N was determined on a Bran and Luebbe Traacs
800 autoanalyzer (Bran and Luebbe, Elmsford, New York) following standard methods (Method 780-86T ammonia in water and wastewater).
The formula includes iron, which uses The Real Amino Acid Chelate System (TRAACS
) that binds minerals to amino acids to create an organic molecule the body can use easily.
1990) using a TRAACS auto-analyser (Bran and Luebbe, Basingstoke, UK).
(1990) Operation manual for Bran and Luebbe TRAACS 800 Continuous-Flow Analytical System.
Total Kjeldahl nitrogen was determined colorimetrically (Traacs 800, Bran + Luebbe, Elmsford, New York).
Total Kjeldahl nitrogen content was determined colorimetrically on dried needles (Traacs 800, Bran + Luebbe, Elmsford, New York).
The digest was analyzed for ammonia by continuous flow colorimetric analysis (Technicon TRAACS
Ammonium and [MATHEMATICAL EXPRESSION NOT REPRODUCIBLE IN ASCII] concentrations in the extracted solution were measured colorimetrically using an automated segmented continuous flow analyser (Traacs
800, Bran and Luebbe).
N[H.sub.4] was extracted by shaking a separate subsample of 6 g of soil with 30 mL of 2 mol/L KCl, filtering the extract with a Seraclear filter, and analyzing the supernatant using Traacs
800 autoanalyzer methods (Bran and Luebbe 1986).