The FAO takes time putting on the table one of the major problems of agriculture in the short, medium and long term: the degradation of the soil . Not so long ago, even without big data revolutionizing this sector, he produced a report with the collaboration of two hundred scientists and researchers thanks to soil data from more than 50 countries that he called: State of the World’s Soil Resources.
The main objective of it was to obtain a clear image of how the world’s soils were, the same one from which every day the food that reaches the stores comes out and keeps agriculture going.
Multiple conclusions can be drawn from the report when reading it, although the main one is that a black shadow hovers over the cultivated lands of the five continents, Spain included.
But before talking about them, the first thing to ask yourself is something important: what is soil degradation? And without there being a simple answer, we can say that it is, basically, a change in the ecosystem, a negative variation in its health that translates into its inability to produce adequately with variable results from the absence of crops to a lower productivity of them.
The document State of the World’s Soil Resources presents ten threats to soil functions that no farmer can and should not forget:
The soil has salts (Na, K, Mg, Ca, sulfate, carbonate and bicarbonate) naturally and in a secondary way or salinization that arises from human intervention with actions such as inadequate irrigation with waters rich in salt or insufficient drainage.
2. Nutrient imbalance.
It has two aspects: On the one hand, the soils do not receive enough nutrients to achieve their optimal development and performance and, on the other hand, they receive an excess of them that have as a consequence the deterioration of water quality and the high emission of gases greenhouse effect, such as nitrous oxide and is intrinsically linked to blocking elements that are not available to plants, but are available to pollute. In both cases, this imbalance becomes the key to lower or simply bad production.
3. Acidification and alkalinity.
The pH of the soil decreases due to the accumulation of hydrogen and aluminum ions and the disappearance of basic cations such as Ca, Mg, K and Na that produces the leaching or displacement of soluble substances. In the case of Spain, a large part of the territory has the opposite problem, the soils are calcareous and alkaline and this condition can generate fixations and blockages of some important nutrients, such as phosphorus, iron and others.
Soils receive chemicals and materials that are pollutants, either by pollution itself or by excess elements initially necessary that are in concentrations higher than normal.
5. Loss of organic carbon (COS).
Soil organic carbon is that which remains after the partial decomposition of any material produced by living organisms and is key in the global carbon cycle through the atmosphere, vegetation, soil, rivers and the ocean. Its loss in the soils responds to its conversion into carbon dioxide or methane (both greenhouse gases) and to its physical disappearance from the soil by erosion.
6. Loss of biodiversity.
Not much explanation is needed, the diversity of micro and macro-organisms in the soil is seriously diminishing.
When they are very humid and drowned, there is insufficient oxygen in the pore space for the roots of the plants to breathe, in addition there is another effect the accumulation of carbon dioxide and ethylene near the roots.
As the surface soil and the subsoil are denser and less porous, the roots cannot penetrate and, in addition, they have problems for the exchange of water and gases.
The hydric occurs when the flow of surface water transports the detached soil particles giving rise to furrows or gullies. Wind power arises when the wind or air from the dry or loose soil causes the particles to be transferred to other places. The tillage takes place when the action of man makes an inadequate distribution on the land.
It refers to covering the natural cover of the earth with buildings, roads, etc. that prevent you from breathing properly.