How do you open the string closure on farm seed bags?

Bag closing machines come in two types -- single or double thread. To open either type, first look to see which side of the bag has "loop-de-loops" on it. When facing that side, with the sewn edge of the bag up, pull on the thread(s) from the left end. If there is only one, pull on the side away from the loop-de-loops. If there are two, pull one on each side of the bag; you'll need to pull one twice as fast as the other. Double-thread closures are trickier in that if you pull one thread too fast or too slow it will tangle up badly. Just go slow.

Or, you can get a pair of scissors and just cut the string off.