During the dry season, one cannot help but see all the burning going on. Many people have told me that they do not like to see the burning because of all the collateral damage to trees, structures and the obvious exposure of the bare earth to heavy rain and erosion (loss of top soil). This is fairly obvious to most people, including the ones doing the burning. How burning contributes to climate change is also something to consider.
I personally see burning as a loss of one of the most helpful building blocks for healthy food producing soil, “carbon”. When an area is burned, carbon is released into the atmosphere and ash is left. Ash is mostly lime, and lime changes the PH balance of the soil, which affects the plants ability to absorb nutrients. This affects the quantity of food that a field can produce (lower crop yield).
So what can a farmer or gardener do instead of burn? There is the time tested practice of pull and drop or cut and drop with grasses and weeds. In this practice, the pulled or cut material will break down naturally and the rain will slowly leach nutrients down to the root zone of whatever you plant. Using cows, horses, goats and sheep in intensive cell grazing (keeping the animal contained in an area) can accomplish much of the work of breaking down unwanted vegetation while adding value in the form of meat and milk and in the case of horses, draft (plowing) and transportation.
In areas that are thick with brush, vines and trees, there is another approach called Hugelkultur beds. This is where stumps, branches and brush are piled, covered with earth, and planted with trees, bushes ect. If you’ve ever seen a house built on a hillside where a pad (flat area) is made by pushing the earth and vegetation over the downhill side, the benefit of this practice can be observed. Trees and plants on the down hill edge of the pad will look noticeably bigger and healthier than others of their kind planted in plain top soil. The reason for this is the soil structure created here has available air for the microbes that feed the plant, slow released nutrients and minerals (including carbon) and some good drainage. When drought comes, the buried wood holds reserve moisture that the trees and plants can access.
There is another process called wood gasification, or pyrolysis, where a specially constructed oven (see video below) heats wood debris, but only burns the gas escaping to create charcoal or “Bio Char”. Bio Char is almost pure carbon, and can be crushed and added to soils to dramatically improve its productivity. This practice can significantly reduce the bulk of branches and sticks as well. The heat released in the process of making “Bio Char” can be utilized for drying or heating purposes, of which there are many. Your comments and suggestions are most welcome.