When an empty textline field is stored it will be not indexed at all and the field will not appear in the Solr index.

Used version of the solr-bundle:

ezsystems/ezplatform-solr-search-engine v1.5.1
on eZ Platform V 2.0

This means that you cannot search in you application for an empty field value!

See: ezplatform-solr-search-engine/lib/FieldMapper/ContentTranslationFieldMapper/BlockDocumentsContentFields.php

if ($indexField->value === null) {
  // continue; // Fix fd see http://confluence.extranet.silversolutions.de:8090/display/EZcom/Search+issues+for+eZ+Systems
}