What to do after a dry summer?
After tough vintage, with a dry summer, the obvious reaction is to build up your vines. Many growers think of incorporating animal or chicken manure into the soil. They see piles of manure and think; "I'm adding a lot of organic matter and goodness to the soil."
Manures are actually organic material, not organic matter. Manures need to be broken down by micro-organisms to work. Manures are unstable in the soil and as much as 90 percent of it disappears by decomposition.
A good test is to buy manure now and compost it for a year. Record the weight difference.
What you need is organic matter which is stable in your soil.
What's the difference between organic material and organic matter? Organic material is anything that was alive and is now in or on the soil. For it to become organic matter, it must be decomposed into humus. Humus is organic material that has been converted by microorganisms to a resistant state of decomposition.
Organic matter is stable in the soil. It has been decomposed until it is resistant to further decomposition.
Products that are fully composted are the equivalent to many tonnes of chicken or animal manure because it consists of Humic material and Organic Carbon both of which are stable and long lasting in your soil.