If you live near any horses or cattle, maybe you can talk the rancher out of some of the used hay in the stables, in return for removing it. You would need to let that cure for awhile before putting it into the garden, because large animal manure is very rich and will burn the plants if it is used too soon. Also, don't use any stable material from race horses -- according to the newspapers, a lot of those critters are doped up with who-knows-what kind of drugs.
KITCHEN WASTE
We also add raw vegetable and fruit waste from the kitchen, eggshells, and coffee grounds as well as the coffee filters. We don't have a compost pile -- the terra preta garden itself is the compost pile.
LEAVES
We planted a couple of deciduous fruit trees on the edge of the terra preta garden. When the leaves drop off of the trees, we will only have to move them a few feet to get them into the terra preta garden. We will just leave the leaves on the top of the ground to rot, the way that Nature does it.
HAY
I have learned that alfalfa roots can go as deep as 250 feet, so it would make an excellent addition if you want to return minerals to the surface. You don't have to dig up those 250-foot deep roots to get the benefit. When you cut the alfalfa down, return it to the terra preta as hay mulch, and the minerals will be added to the soil as the hay decomposes.
FISH
One of our correspondents says that his group buys rotten fish very cheaply and chops them up, while holding their noses, of course; and then they bury this stinking mess into their terra preta garden. It's a rich source of all kinds of stuff for the microlife in the soil.
Just be thankful that you're not one of their neighbors.
SEAWEED
We haven't actually added this yet, we just bought the bottle recently. But I'm sure that it will add a lot of other minerals to the terra preta. It was recommended by Dr. Jensen, and so that's good enough for me.
If it smells like fish, then try to use it on non-windy days in order to spare your neighbors.
HYDROGEN PEROXIDE
We recently learned that food-grade hydrogen peroxide, when properly diluted and watered into the ground, will add oxygen to the plants' root systems and send them into an ecstasy of growth. We haven't tried it yet, but will be doing so soon. I have no doubt that it will work.
NOTE: Use ONLY the food-grade hydrogen peroxide, and handle it with gloves because it will burn you if you spill it.
