Perhaps you should try some spelling variations:
"supply case irrigation schemes." » "supply case irrigation scheme.", "supply case irrigation systems.", "supply scale irrigation schemes.", "supply use irrigation schemes.", "supply change irrigation schemes.", "supply cost irrigation schemes.", "supply curve irrigation schemes.", "supply costs irrigation schemes."
"supply chain irrigation system." » "supply chain irrigation systems.", "supply chain irrigation water.", "supply chain irrigation scheme.", "supply grain irrigation system.", "supply change irrigation system.", "supply basin 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 chain irrigation system.") or ("supply case irrigation schemes."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply chain irrigation system.") OR ("supply case irrigation schemes."))*.
• Removing quotes may allow a broader search: (( supply chain irrigation system. ) or ( supply case irrigation schemes. ))*.