Perhaps you should try some spelling variations:
"supply chain's irrigation systems." » "supply change irrigation systems.", "supply canal irrigation systems.", "supply grain irrigation systems.", "supply chains irrigation systems.", "supply channels irrigation systems.", "supply china irrigation systems.", "supply chain's irrigation system."
"supply large irrigation schemes." » "supply large irrigation scheme.", "supply farm irrigation schemes.", "supply drip irrigation schemes.", "supply scale irrigation schemes.", "supply charges irrigation schemes.", "supply targets irrigation schemes.", "supply curve irrigation schemes."

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's irrigation systems.") or ("supply large irrigation schemes."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("supply chain's irrigation systems.") OR ("supply large irrigation schemes.")).
• Removing quotes may allow a broader search: (( supply chain's irrigation systems. ) or ( supply large irrigation schemes. )).
• Adding a wildcard symbol may retrieve word variants: (("supply chain's irrigation systems.") or ("supply large irrigation schemes."))*.