Agricultural is related to Crop. Crop is related to Output. Output is related to Result. Result is related to Dark. 
Awful is the opposite of Nice. Nice is the opposite of Horrible. Killing can cause/lead to Horrible. 
Agricultural <--RelatedTo--> Crop <--RelatedTo--> Output <--RelatedTo--> Result <--RelatedTo--> Dark 
Awful <--Antonym--> Nice <--Antonym--> Horrible <--Causes-- Killing 