id	keyword
american_scientific_journal-3855	tillage
american_scientific_journal-3855	yields
american_scientific_journal-3855	methods
american_scientific_journal-3855	millet
american_scientific_journal-3855	pearl
american_scientific_journal-3855	conservation
american_scientific_journal-3855	soil
american_scientific_journal-3855	root
american_scientific_journal-3855	research
american_scientific_journal-3855	namibia
american_scientific_journal-3855	nsct
american_scientific_journal-3855	farmers
american_scientific_journal-3855	crop
american_scientific_journal-3855	mean
american_scientific_journal-3855	mulch
american_scientific_journal-3855	trf