Perhaps you should try some spelling variations:
irrigation requirements » irrigation equipment, nutrition requirements
requirements base » requirements based, requirements case, requirements phase
base excitation » based elicitation, base excision, pre excitation
excitation from » elicitation from, excitation fronts, exportation from
seeds » seed

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

• Performing a fuzzy search may retrieve terms with similar spellings: irrigation requirements base excitation from (seeds OR needs)~.
• The words AND, OR and NOT may confuse the search; try adding quotes: "irrigation requirements base excitation from (seeds OR needs)".
• Adding a wildcard symbol may retrieve word variants: irrigation requirements base excitation from (seeds OR needs)*.