Perhaps you should try some spelling variations:
africa fertilizer » affect fertilizer, rich fertilizer, from fertilizer
technical experts » technical expertise
fertilizer usage » fertilizer use, fertiliser use, fertilizer type
usage assessment » stage assessment, image assessment, use assessment
assessment 3 » assessment 4, assessment 1, assessment 3.1
3 technical » 2 technical

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

• Performing a fuzzy search may retrieve terms with similar spellings: africa fertilizer usage assessment 3 technical experts.~.
• Adding a wildcard symbol may retrieve word variants: africa fertilizer usage assessment 3 technical experts.*.