Agriculture Fighting Climate Change

Our current agricultural practices are a major contributor to climate change. A whopping 14% of all greenhouse gas emissions are attributed to the way we grow, process, distribute and consume food, and an additional 18% are due to deforestation largely driven by the clearing of forests for agricultural land. This problem can only intensify as our population grows. Imagine how many more greenhouse gasses will be pumped into our atmosphere in 2050 when the estimated world population reaches 9.1 billion. Without a drastic change to the way we produce food, we simply wont survive.

Traditional agriculture, and even organic agriculture, relies heavily on tilling the soil to prepare the ground for planting. Tilling, however, has a number of undesirable side-effects, such as: soil erosion, loss of organic matter, destruction of living soil microbes, dependence on heavy machinery, loss of soil structure, loss of nutrients and soil compaction. However, there is another negative side-effect of tilling that many people may be unaware of, and that is carbon oxidization. Tilling causes the carbon in the soil to be oxidized which releases it (the carbon) into the atmosphere. This, of course, increases greenhouse gasses and contributes to climate change.

Over the past 30 -40 years there have been people experimenting with no-till agriculture. No-till agriculture uses a range of practices so that tilling is rarely or never used, resulting in the following advantages: improved soil structure, better water and nutrient holding capacity and less use of machinery. However, one of the biggest advantages of no-till agriculture is that the soil can store much more carbon. This means that there will be more carbon in the plants and soil and less in the atmosphere. In other words, agriculture has the potential to become a fighter against climate change. Wouldnt that be a turnaround?

So far, no-till agriculture has been heavily dependent on herbicides. When I attended agricultural college in the late eighties, no-till agriculture was in its early developmental stages. It was seen as unorthodox and alternative a little way out. We were taught that paddocks needed to be sprayed out with herbicide first. The dead plants, which were called stubble, were left standing. Then seed was sown through the stubble, using a direct-drilling method. The stubble offered soil protection and increased biomass, which is great. However, the method was completely dependant on chemical herbicides.

The organic industry, which is generally seen as an environmentally positive industry, does things quite differently. They use a combination of green-manure crops and tilling. Green-manure crops, such as oats, millet, clover, and many more, are commonly used and sown into a paddock prior to planting the target species. For example, lets say our target species is corn. Prior to the corn being planted in spring, a green-manure crop, such as oats, is planted out in autumn and allowed to grow through winter. In spring, the oats are tilled into the soil and the corn is sown. This is an excellent way of building soil biomass and soil nutrients; however, you still have the negative effects of soil tillage, mainly the release of carbon into the atmosphere.

As you can see, both no-till and organic agriculture have their pros and cons. No-till methods store carbon but rely on chemicals. Organic farming uses no chemicals but relies on tilling.

A method that combined the soil protection of no-till farming and the non-toxicity of organic farming would be ideal agricultural heaven. There are people around the world who are working towards this ideal. These pioneers, referred to as no-till organic farmers, are still working out a few bugs.

With this revolutionary method, a green-manure cover crop is planted out prior to the target crop. However, when the time comes to plant the target species, the green-manure crop is not tilled into the soil, and neither is it killed with herbicide. Rather than being tilled or sprayed, the green-manure crop is killed using a mechanical method called crinking. A large roller with blunt blades set at intervals is rolled over the green-manure crop. The blades crink, but not cut, the stems of the cover crop. It also flattens the cover crop so that it becomes a dense, dead organic matt covering the soil. Then seed is sown using a direct-drilling method through the dead matt. The dead green-manure crop is still attached to the soil via its dying roots. This offers excellent soil protection and the dense matt offers weed suppression and moisture retention. It also increases soil biomass and builds nutrients.

The beauty of this method is the fact that agricultural land can act as a giant carbon sink. This is a complete turnaround as agriculture is presently a major producer of greenhouse gasses. It is believed that no-till farming has the potential to store a staggering 3000 pounds (1360 kilograms) of carbon per acre. No-till organic farming has the potential to become a major fighter against climate change, and provide healthy, chemical-free food at the same time.

On a small scale, no-till organic food production is actually very easy. Food4wealth is an ideal example of this revolutionary way of producing food. Food4wealth is a small-scale, easy-to-follow, organic food-growing method that retains a dense coverage of plants and uses no tilling. A food4wealth plot is just like a mini-carbon sink. It takes carbon from the atmosphere and turns it into healthy, organic food.

For more information go to: Food4Wealth

by Jonathan White B.App.Sci. Assoc. Dip.App. Sci.