Perhaps you should try some spelling variations:
"support trade irrigation schemes." » "support trade irrigation scheme.", "support pradesh irrigation schemes.", "support scale irrigation schemes.", "support grain irrigation schemes.", "support trainer irrigation schemes.", "export trade irrigation schemes.", "import trade irrigation schemes."
"supply main irrigation systems." » "supply basin irrigation systems.", "supply grain irrigation systems.", "supply saline irrigation systems.", "supply chain irrigation systems.", "supply ann irrigation systems.", "supply many irrigation systems.", "supply main 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: (("support trade irrigation schemes.") or ("supply main irrigation systems."))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (("support trade irrigation schemes.") OR ("supply main irrigation systems.")).
• Removing quotes may allow a broader search: (( support trade irrigation schemes. ) or ( supply main irrigation systems. )).
• Adding a wildcard symbol may retrieve word variants: (("support trade irrigation schemes.") or ("supply main irrigation systems."))*.