Perhaps you should try some spelling variations:
"supply service irrigation system." » "supply service obligation system.", "supply surface irrigation system.", "supply service obligations system.", "supply service irrigation water.", "supply service irrigation scheme.", "supply service innovation system.", "supply services irrigation system."
"support drip irrigation systems." » "support drip irrigation waters.", "support drip irrigation schemes.", "support drip innovation systems.", "support deep irrigation systems.", "support grid irrigation systems.", "support during irrigation systems."

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

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