I have read over the following passage many times in my life, mentally agreeing that salt which has lost it's saltiness if worthless. I could picture in my mind, salt being used to keep weeds and grass down around someone's doorsteps, just as we use 2-4-D or Roundup today. I had even thrown out the salted water after making homemade ice cream many times in a spots where I wanted to kill the grass or weeds, without ever stopping to ask the question, "How can salt prove beneficial to a dunghill?"
Luke 15:34-35 Salt is good: but if the salt have lost his savour, wherewith shall it be seasoned? It is neither fit for the land, nor yet for the dunghill; but men cast it out. He that hath ears to hear, let him hear.
I realized that I didn't know the answer and had never heard anyone comment on how salt can be beneficial for use in a dunghill, but there must be some way, since once it has lost it savour, it is no longer good for the dunghill. My experience with worthless salt was limited to salt in a shaker after it had absorbed moisture and would no longer properly release from the shaker. Growing up in the 50's, I also had experience casting out salt after it had been used to cure meat and had performed it's task. We even had a cow and maintained a dunghill which was used primarily to grow fishing worms and put under watermelon hills, but we never salted it. I was raised in a farming community but I had never heard of anyone putting salt in a dunghill, so I decided to search for the answer. Here is what I found that some of you might be glad to know also: Salt can enrich a manure pile by converting the ammonia that would be released in gaseous form into two solid components, carbonate of soda and muriate of ammonia, both useful to plant growth. The use of salt in manure piles is recommended for this purpose in the following article:
From the Farmer's Daily: http://books.google.com/books?id=BJZTAAAAIAAJ&pg=PA207&lpg=PA207&dq=salting+a+dunghill&source=bl&ots=auL69bfM-c&sig=tm9wVPio5qMeZJOZwtRZCCaWnJc&hl=en&ei=73c8TfHUOMb_lge5w4zqBQ&sa=X&oi=book_result&ct=result&resnum=6&ved=0CD4Q6AEwBQ#v=onepage&q&f=false
Apparently the people of Jesus' day knew that salt improved the quality of the dunghill. If I had a cow today, I'd sure try it, especially under my watermelons!