Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme
canal irrigation » scale irrigation
drop irrigation » drip irrigation, crop irrigation, from irrigation
supply canal » supply annual, supply rural, supply case
supply drop » supply crowd
systems. » system.

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

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