In a world that is losing fertile soils at a dramatic rate, governments, scientists and agricultural organizations around the world are looking for ways to decelerate the destruction of soils and even revert it, which are at the same time effective and easy to implement. Leading among the groups directing soil conservation and reparation is the Food and Agriculture Organization (FAO) of the United Nations, which has come up with its own comprehensive proposal: conservation agriculture, or CA by its initials. The Organization explains it like this:
Conservation Agriculture is a farming system that promotes minimum soil disturbance (i.e., no tillage), maintenance of a permanent soil cover, and diversification of plant species.
The FAO also states:
It enhances biodiversity and natural biological processes above and below the ground surface, which contribute to increased water and nutrient use efficiency and to improved and sustained crop production.
So, first they give a definition and then they offer practical reasons to get interested in conservation agriculture. This is all well and good, but what does ‘maintenance of a permanent soil cover’ and ‘increased water and nutrient use efficiency’ actually amount to? First things first, let’s start by the definition (as we’ll be getting into more details in upcoming articles): by now we can break it down into three main elements, which are also the main three principles of conservation agriculture.
Minimum tillage and soil disturbance means planting directly above ground as much as possible, instead of breaking into the soil to bury the seeds or the stalks or whatever have you. Though the soil is a part of a wider ecosystem (say, a forest or a meadow), it is also an ecosystem of its own. So, the rationale behind this is that the less we disturb the functioning of that soil ecosystem by exposing and destroying beneficial fungi and bacteria, for example, the more we can reap the accumulating benefits of it and the less we have to work to re-establish a soil ecosystem with each planting season.
Traditional methods of tillage gradually impoverish soil by destroying the topsoil before it builds up.
Maintenance of a permanent soil cover simply means keeping your soil planted at all times. It doesn’t even matter if it’s something you can eat (though if you can, even better!), only that if soils are left uncovered, they begin to receive weeds and to erode. As simple as that. And if weeds overgrowing a field mean more work to take them out alongside all the nutrients that they have absorbed with them, planting cover crops (a critical term) means maintaining the cycle of nutrients and smothering the weeds with the aid of plants that you will then rebury into the same ground so that it conserves the nutrients they used.
Cover crops are crimped into the ground after they have fully grown, as with this mixture of rye and hairy vetch.
- Finally, diversification of plant species means no more thousands of hectares of monocultures. Even though it may look like it’s more efficient, monoculture means massive losses when a plague hits (whereas plagues are less frequent when a variety of plants mutually repels the plagues of the others) as well as massive losses of nutrients and water; because the plants of the same species have all their root systems at the same level, this means that they won’t take up the underground water and nutrients.
These are the three main principles of conservation agriculture, an upcoming revolution of which organic fertilizers are another essential part. As soils keep eroding and consequently becoming scarcer, their price rises and the costs of their conservation begin to offset the ever-increasing costs of losing soils to degradation. Conservation agriculture is really the future, and we’ll cover the developments made now towards that future in upcoming articles covering everything from specific conservation techniques to the statistics of long-term yields of CA. In the meantime, happy growing!