For the stuffing: Combine the wild rice, water, and 1/2 teaspoon of the salt in a medium saucepan and bring to a boil. Reduce heat to low, cover, and simmer until the rice is tender and just bursting, about 30 minutes. (Times may very depending on the brand of rice used.) Drain and set aside.
Adjust an oven rack to lowest position and remove other racks. Preheat to 325 degrees F.
Melt the butter in a large skillet over medium-high heat. Add the onion, apple, celery, garlic, thyme, mace, remaining 1 teaspoon salt and pepper, to taste. Cook until the vegetables soften, about 5 minutes. Stir in sausage, breaking it up with a wooden spoon and cook until it loses most of its rosy color, but not so much that it's dry, about 5 minutes more. Stir in the cooked wild rice, pecans, and parsley into the vegetable mixture. (This can be made the day before.)
For the turkey: Remove turkey parts from neck and breast cavities and reserve for other uses, if desired. Dry bird well with paper towels, inside and out. Melt the butter together with the poultry seasoning. Salt and pepper inside the bird cavity. Loosely add the stuffing to the cavity and set the bird on a rack in a roasting pan, breast-side up, and brush generously with the seasoned butter, then season with salt and pepper. Tent the top of the bird with foil.
Roast the turkey for about 2 hours undisturbed. Remove and discard the foil. Baste with the remaining butter. Increase oven temperature to 425 degrees F and continue to roast until an instant-read thermometer registers 165 degrees F when inserted into the thickest part of the thigh, about 20 to 25 minutes more. Remove turkey from oven and tent with foil for 15 minutes before carving.