Perhaps you should try some spelling variations:
"supply chain irrigation schemes." » "supply chain irrigation scheme.", "supply chain irrigation systems.", "supply change irrigation schemes.", "supply basin irrigation schemes.", "supply chain integration schemes."
irrigation system » irrigation systems, irrigation water, irrigation scheme
supply change » supply charges, supply chains
supply case » supply cost, supply curve, supply costs

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