id	keyword
agsci-509	soil
agsci-509	field
agsci-509	testing
agsci-509	sample
agsci-509	sampling
agsci-509	plant
agsci-509	fertilizer
agsci-509	farmer
agsci-509	crop
agsci-509	use
agsci-509	analysis
agsci-509	nigeria
agsci-509	laboratory
agsci-509	chemical