Perhaps you should try some spelling variations:
irrigation schemes » irrigation scheme, irrigation systems
basin irrigation » drip irrigation, canal irrigation, farm irrigation
aid conservation » land conservation, bird conservation, wild conservation
supply basin » supply asia, supply based, supply design
supply aid » supply asia, supply a, supply ann

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

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