Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
spate irrigation » scale irrigation, water irrigation, surge irrigation
supply spate » supply system, supply side, supply water
supply cote » supply costs, supply case, supply cold
supply cost » 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 cote) or (supply cost)) irrigation schemes. ) or ( supply spate irrigation schemes. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( ((supply cote) OR (supply cost)) irrigation schemes. ) OR ( supply spate irrigation schemes. )).
• Adding a wildcard symbol may retrieve word variants: (( ((supply cote) or (supply cost)) irrigation schemes. ) or ( supply spate irrigation schemes. ))*.