Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
irrigation system » irrigation systems, irrigation water, irrigation scheme
chain irrigation » grain irrigation, change irrigation, basin irrigation
et irrigation » led irrigation, _ irrigation, water irrigation
supply et » supply _, supply a, supply 3

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

• Performing a fuzzy search may retrieve terms with similar spellings: (( supply et irrigation schemes. ) or ( supply chain irrigation system. ))~.
• If you are trying to use Boolean operators, they must be ALL CAPS: (( supply et irrigation schemes. ) OR ( supply chain irrigation system. )).
• Adding a wildcard symbol may retrieve word variants: (( supply et irrigation schemes. ) or ( supply chain irrigation system. ))*.