Perhaps you should try some spelling variations:
"support grid irrigation schemes." » "support grid irrigation scheme.", "support drip irrigation schemes.", "support syria irrigation schemes.", "support crop irrigation schemes.", "support agri irrigation schemes.", "support grant irrigation schemes.", "support group irrigation schemes."
"supply spate irrigation systems." » "supply scale irrigation systems.", "supply water irrigation systems.", "supply surface irrigation systems.", "supply system irrigation systems.", "supply side irrigation systems.", "supply spate irrigation system."

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• Performing a fuzzy search may retrieve terms with similar spellings: (("support grid irrigation schemes.") OR ("supply spate irrigation systems."))~.
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