Variables: total_organic_carbon Keywords: land use Substances: Acemetacin (FSQKKOOTNAMONP-UHFFFAOYSA-N) 4-Acetamidoantipyrin ( N-Acetyl-4-Aminoantipyrin 4-AAA) (OIAGWXKSCXPNNZ-UHFFFAOYSA-N) 2-4-D (OVSKIKFHRZPJSS-UHFFFAOYSA-N)