Biochar is made when wood, bones, leaves, or manure (or any vegetable matter) is heated or burned at low temperatures in a kiln, this is done by limiting oxygen to the process and keeping the temperature below 700 F. The resulting half-burned charcoal-looking material is biochar, and is ready to be added to your soil.

Biochar like wood ash is alkaline and works best when used as a soil amendment on acidic soils. Mixing biochar with compost works best by helping to properly age the biochar and add the fertility boosting effects of compost.

As with any composting system, you cannot use meat, fats, or dairy products, which will ruin the compost and attract insects and mice and other vermin as well as stinking up your house. You can use newspaper, cardboard, fruit, vegetable matter, bread, teabags, and coffee grounds.

Soil can be improved by using a variety of readily available organic materials. As mentioned above, composting is a wonderful idea and will provide you with a steady supply of “ black gold” for your garden.

Other sources of organic materials are

• coffee grounds (I go to my local Starbucks and they are very nice about providing buckets of their coffee grounds);
• cover crops such as legumes, buckwheat, and cereal rye can be grown and then gently turned under and buried in the top layer of soil (it is a good policy never to leave your soil bare and open to the elements);
• dried manure (you cannot use fresh manure, it will burn your plants).
• Peat moss, wood chips, sawdust, grass clippings, leaf mold, and shredded and composted leaves are all wonderful sources of organic material for your garden; these all will lower your pH and make your garden more acidic.
• You can raise your pH by the addition of crushed rocks (rock dust), ashes from your fireplace or any wood burning, bone meal, and crushed oyster shells.
• If you live near the ocean, lakes or any body of water that can be used for fishing you can use dead fish to improve your garden soils. Salt water fish are better than fresh water but both will suffice. Bury any fish or fish parts that you are not eating into your garden; they are wonderful sources for many minerals and trace elements and have been used for centuries to enhance garden soils.
• Dried seaweed such as kelp is also an excellent source of minerals, nutrients, and phytonutrients such as growth hormones.

The ideal pH of your garden should be between 6.5 and 6.8, which is very mildly acidic. That pH range has been found to be optimal for plants to be able to uptake minerals and other charged particles from the soil. Lower or higher pH levels result in a binding of the nutrients and results in them being unavailable for uptake by your garden plants.

Growing plants in the wrong pH will result in disaster.

Simple soil pH kits are available in any garden center and I would buy several of them to have on hand.  Most soils found east of the Mississippi river are slightly acidic in nature.

Soils that are too acidic can be sweetened by the addition of

• powdered limestone (lime), which is alkaline and will raise the pH into your target range of 6.5 to 6.8.
• you can also use wood ashes from your fireplace if no lime is available, which also contains potassium and many trace elements. Do not use more than 2 pounds of ashes per hundred square feet of garden (for those of you who are math-challenged, this means a ten foot by ten foot garden space, or twenty feet by five feet, etc.).
• Another formula to use to sweeten your soil is to add 4 pounds of lime per one hundred square feet for every one point of pH below 6.5.
• If you have alkaline soils (which are much less common) you can use sulphur on it to make it more acidic and you can also use pine needles or other acidic materials. e formula for the addition of sulphur to alkaline soils is 1 pound of sulphur per one hundred square feet per each point of pH above 7.5.

And this are just some of the ways of doing it. If you want to find out how to build a healthy soil using: