Perhaps you should try some spelling variations:
"support grid irrigation schemes." » "support grid irrigation systems.", "support grid irrigation systemss.", "support grain irrigation schemes.", "support drip irrigation schemes.", "support gray irrigation schemes.", "support agri irrigation schemes.", "support grant irrigation schemes.", "support group irrigation schemes."
"supply basin irrigation scheme." » "supply basin irrigation systems.", "supply drip irrigation scheme.", "supply canal irrigation scheme.", "supply farm irrigation scheme.", "supply asia irrigation scheme.", "supply based irrigation scheme.", "supply design irrigation scheme."

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

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