id	keyword
american_scientific_journal-3352	soil
american_scientific_journal-3352	properties
american_scientific_journal-3352	variability
american_scientific_journal-3352	table
american_scientific_journal-3352	clay
american_scientific_journal-3352	values
american_scientific_journal-3352	samples
american_scientific_journal-3352	content
american_scientific_journal-3352	variation
american_scientific_journal-3352	field
american_scientific_journal-3352	mean
american_scientific_journal-3352	research
american_scientific_journal-3352	surface