Perhaps you should try some spelling variations:
fertilizer trade » fertilizer trials, fertilizer usage, fertilizer price
technical report » technical support, technical experts, technical review
fertilizer type » fertilizer use
assessment e6 » assessment 16, assessment el, assessment 2.6
e6 technical » 6 technical, der technical, ecm 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 trade) or (fertilizer type)) assessment e6 technical report.~.
• If you are trying to use Boolean operators, they must be ALL CAPS: africa ((fertilizer trade) OR (fertilizer type)) assessment e6 technical report..
• Adding a wildcard symbol may retrieve word variants: africa ((fertilizer trade) or (fertilizer type)) assessment e6 technical report.*.