Perhaps you should try some spelling variations:
"supply crop irrigation schemes." » "supply crop irrigation scheme.", "supply drip irrigation schemes.", "supply scale irrigation schemes.", "supply canal irrigation schemes.", "supply crowd irrigation schemes.", "supply from irrigation schemes.", "supply europe irrigation schemes."
"supply flood irrigation systems." » "supply flood mitigation systems.", "supply led irrigation systems.", "supply farm irrigation systems.", "supply food irrigation systems.", "supply from irrigation systems.", "supply crowd irrigation systems.", "supply flood irrigation system."

You may be able to get more results by adjusting your search query.

• Performing a fuzzy search may retrieve terms with similar spellings: (("supply flood irrigation systems.") or ("supply crop irrigation schemes."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply flood irrigation systems.") OR ("supply crop irrigation schemes.")).
• Removing quotes may allow a broader search: (( supply flood irrigation systems. ) or ( supply crop irrigation schemes. )).
• Adding a wildcard symbol may retrieve word variants: (("supply flood irrigation systems.") or ("supply crop irrigation schemes."))*.