Perhaps you should try some spelling variations:
fertilizer usage » fertilizer use, fertiliser use, fertilizer type
usage assessment » stage assessment, image assessment, use assessment
bio fertilizer » bio fertilizers, from fertilizer, rich fertilizer
vi technical » ii technical, die technical, iii technical
i technical » ii technical, 2 technical, 3 technical

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

• If you are trying to use Boolean operators, they must be ALL CAPS: bio fertilizer usage assessment ((vi technical) OR (i technical)) experts.~.
• Adding a wildcard symbol may retrieve word variants: bio fertilizer usage assessment ((vi technical) or (i technical)) experts.*.