THE IMPORTANCE OF ORGANIC MATTER IN THE SOIL

We are used to hearing the term organic matter over and over again. We can have a slight idea that the greater the quantity of this component in a soil, the greater the quantity it will have. However, we do not see the technical aspect that surrounds the concept of organic component. Today, in Gardenprue, we are going to reveal some interesting aspects of what we know as organic matter.

If we had the ability to divide a soil into 2 components, we would do it as follows:

• Mineral materials
• Organic matter

That a soil has mineral substances is good, but it is even more so if it has the latter. In fact, a lack of organic substances would completely prevent a soil from supporting any plant or vegetable.

WHAT IS KNOWN AS ORGANIC MATTER

Basically we are talking about the remains of living beings and plants in the process of decomposition, helped by temperature, water and the intervention of more living beings. All these materials undergo a decomposition process that end up forming functional minerals for the plant, once it has the ability to absorb them.

To know a little about what we are talking about, we are going to take stock of the process:

1. We start from organic matter without decomposing (or slightly decomposed).
2. Through HUMIFICATION, we have humus . Does worm castings sound familiar to you?
3. The process known as MINERALIZATION begins. Humus breaks down into more elements.
4. Once this operation is completed, we have minerals (nitrogen, calcium, phosphorus, etc.) that can be used by the plant.

SO, IS IT THROWING NATURAL DEBRIS ON THE GROUND AND “THAT’S IT”?

Everything has a process. Thus, the higher the quality of our soil (seen from the point of view of the biological activity in it and the climatic conditions), the faster the process will have.

As we have already mentioned from time to time, microorganisms are needed to break down the waste and accelerate the humification and mineralization process.

Of course, other variables such as:

• Soil pH ( here  we show you how to do a home analysis for very little money).
• The permeability of the soil.
• Its mineral content.
• The structure and texture of the soil.
• Porosity.
• The outside temperature and humidity.

WHAT IS THE ACCEPTABLE ORGANIC MATTER CONTENT FOR A SOIL?

Although in many areas of Spain we are far from reaching the recommended levels, it is estimated that a percentage indicated for agricultural practice would be between 1.5 and 2%.

Of course, not always the greater amount is the best. Well, there are areas of the planet that have very high concentrations of organic matter (a swamp, for example) and cannot be cultivated in it (although plants with special plant structures do grow that allow their growth in that area).

THE C / N RATIO (CARBON – NITROGEN)

Although we already have an article dedicated to the C / N ratio, it is interesting to comment on its relationship with organic matter.

What this parameter does is tell us the state of humification of the organic matter in our soil. As you know, microorganisms do not break down all compounds, since some are usually easier to break down than others. For example, resins, tannins or lignins are difficult to break down. In contrast, carbohydrates, salts and glycosides are relatively easy to break down.

WHAT IS THE PERFECT VALUE?

Do not get carried away by numbers, because everything is right and explained. An organic matter (be it vegetable compost, vermicompost, green manures, etc.) that has a high C / N ratio (a lot of carbon content), provides fertility scale to the soil and, therefore, low yield in the production of fruits and vegetables.

If the C / N ratio stays low, that is, the nitrogen content is high, we are releasing an excess of nitrogen in the crops, which, as you could see in the article on the importance of nitrogen , is totally inadvisable.

To put values ​​to all this mess, we will say the following:

• C / N <20: organic matter with excess nitrogen.
• 20 <C / N <30: optimal state of the relationship.
• C / N> 30: nitrogen block. Not usable by plants.

WHAT ADVANTAGES DOES ORGANIC MATTER PROVIDE TO THE SOIL?

It would be very easy to say that it improves the properties of the soil, but it goes much further. The influence of this natural element on the soil drastically changes the yield that a crop can offer. And all this because:

IMPROVES THE COLLOIDAL STRUCTURE OF THE SOIL

You’ve probably heard of humic acids. One of the great properties of this compound extracted from organic matter is that it increases the stability of the aggregates.

IMPROVES DRAINAGE

It doesn’t improve it just because. What it does exactly is to unite the particles (which we have talked about before) with a potential lower than that of clays (heavy soils) and higher than that of sands (excessive drainage). Let’s say it is the middle ground between compact soils and light soils. Where the balance is, the optimum is.

HEAT THE EARTH

Compost or manure, by its nature, has dark colors. Regarding the radiation issue, you already know that black absorbs more energy than other light colors. Therefore, a dark soil increases the temperature of the soil, improves the development of the roots and decreases the variation of interior temperature between day and night.

REDUCES WATERLOGGING OF THE SOIL

Due to the aggregates that organic matter forms, incorporating them into the soil improves the balance between the gaseous part and the solid part of the soil. Therefore, if one day we spend with the irrigation, the negative effects will be reduced to a greater extent. The roots will not suffer as many sanitary problems and the crop will not be put so much at risk.

IMPROVES THE ABILITY TO NOT VARY THE PH

The soil has a great buffer capacity . That is, the property it has to avoid changing the pH. Therefore, as you saw in the article on altering the pH of a soil ¸ you have to add large amounts of acidic or basic compounds to achieve a minimum variation in pH.

With organic matter, soil stability is achieved, since it increases its buffer capacity. This is positive if we irrigate with bad water or incorporate acidic or basic fertilizers.

REDUCES THE EFFECTS OF EROSION

Erosion is produced by the disintegration of the particles. When a soil is physically attacked by meteorological phenomena (wind or heavy rain) or by human action (constant trampling), the particles increasingly disintegrate and end up turning into dust (deserts as a major example).

Organic matter helps to avoid the disintegration of these particles, so erosion is substantially reduced.

WATER IS BETTER USED

Although it sounds like utopia, the humic components of compost or manure have a great capacity to absorb water (hydrophilicity). In times of drought, a soil with organic matter will store more water than other “bare” soil.

SUPPORTS MICROBIOLOGICAL LIFE

Both the improvement of the gaseous and solid component of the soil, as well as the humic colloids and the added particles, contribute to the increase in the level of beneficial microorganisms. This translates into a higher fixation of atmospheric nitrogen (less expense in applying fertilizers), a higher rate of nitrification of mineral nitrogen, etc.

In conclusion. We are talking about a cheap product to create (and buy) with great properties when it comes to improving the quality of a floor. If your soil is good, your plants will be even better.