Kids Wooden Swings Do I Need To Cement Into The Ground A New Wooden Swingset?

Do I need to cement into the ground a new wooden swingset? - kids wooden swings

My husband is building our children a wooden swing and said he was not in the earth and cement, which will be very difficult to dig. I do not know if you try to be lazy, but I think they should be buried and are cemented in our house at this address: pinebluffa.htm that http://www.swing-n-slide.com/timberbilt / us 16 meters long instead of 12 meters in length, which allows him a few toys for children.
If this was consolidated into the ground? Or simply being rooted and can secure enough?