Question: what is the first step in the nitrogen cycle when gaseous nitrogen is converted into ammonia
[{'answer': 'nitrogen fixation', 'provenance': [{'wikipedia_id': '59414', 'title': 'Nitrogen cycle', 'start_paragraph_id': 6, 'start_character': 129, 'end_paragraph_id': 6, 'end_character': 146, 'bleu_score': 1.0, 'section': 'Section::::Processes.:Nitrogen fixation.\n'}]}, {'provenance': [{'wikipedia_id': '59414', 'title': 'Nitrogen cycle', 'start_paragraph_id': 7, 'start_character': 0, 'end_paragraph_id': 7, 'end_character': 1339, 'bleu_score': 0.8672608798016931, 'meta': {'yes_no_answer': 'NONE', 'annotation_id': 14908586037941609246}, 'section': 'Section::::Processes.:Nitrogen fixation.\n'}]}]