THE MOISTURE METER OR TENSIOMETER FOR SOIL AND PLANTS

Today we introduce you to a very useful instrument or tool for specialized agriculture. For those who are resistant to the issue of irrigation and do not know exactly the amount and frequency of water contribution to be made according to the crop, we tell you some interesting things about the moisture meter and tensiometers.

The applications of a moisture meter are vast. Obviously, those intended for agriculture and plants are designed to measure the moisture contained in a soil. If we know this data, we will directly know the availability of water that a root can absorb.

Before starting with this topic …

We have an article that will surely bring you up to date on this topic, where we also talk about soil moisture and its behavior.

Check it out before continuing!

Without going into the details of how water acts or is retained in the soil, it can be summarized that there are different levels of “concentration”, for which, when the limit is reached, the roots are unable to absorb more water. It’s kind of like a long, very long straw and a full glass of water. As much as we try to absorb, we do not generate enough suction capacity to make the water rise to our mouth.

THE MAIN PROBLEM THE FARMER FACES WITH SOIL MOISTURE

It is surely what has happened to everyone. In hot weather we water our plants (either in natural soil or in pots), and the next day we see that the soil is apparently dry. We water again. Thus several times until the plant sticks a binge of water that causes stress, mineral deficiencies begin to appear , presence of fungi, physiopathies, etc.

What is happening? Well, very simple. The first layer of soil or substrate dries up due to the action of wind, solar radiation, temperature, etc. However, if we dig a little or introduce our finger, we see that after a few centimeters (or even millimeters), the earth is wet and has enough water so that the roots can absorb it without problems. Correct, then there will be no watering.

On the other hand, the humidity meter is used to keep water levels in the soil always stable, thus avoiding excessive watering or, on the other hand, drought.

If we are very interested in our crops, obviously this moisture meter is very useful.

WHAT IS A BLOOD PRESSURE MONITOR FOR?

At this point in the article you will already know what the tensiometer or moisture meter is about . A tool that consists of one or a series of pikes that are nailed to the ground (the depth is set by you depending on the crop) and provides you with some parameters related to irrigation (humidity, temperature, conductivity, etc.), in order to be able to calibrate or modify the dose and frequency of water supply to your plants.

Despite the name (tensiometer), they are fairly simple instruments to use and adapt to most soils that we can find. Depending on the model, they are designed to withstand inclement weather, since some are left permanently on the ground, in order to gain comfort.

The issue of the depth to which we have to introduce the probe is relatively simple . You have to do several tests, unless we have several spades. It is advisable to do an analysis of the humidity contained in the first levels of the soil, where the most superficial roots are found, and then another analysis with a greater depth, in addition to knowing the water content in the deep layers.

HIGH PRECISION TDR PROBE

It consists of a tool to measure soil moisture in which two rods are driven into the surface layers of the substrate, and in a matter of seconds a series of very interesting data appears on the screen, such as:

• Soil temperature
• Electric conductivity
• Humidity (in%)

WHAT ARE CENTIBARS?

To know what a centibar would be, we have to go to the term bar . No, we do not mean the bar on the corner where we have a coffee or a gin and tonic, but a pressure bar. We would find the millibar, the centibar , the bar. In this regard, we are only interested in the centibar and the following measurement:

If the moisture meter reads:

FROM 0 TO 10 CENTIBARS:

Soil completely saturated with water. We have to stop watering.

FROM 10 TO 30 CENTIBARS:

Sufficient moisture soil is available for most plants. We are doing well and, therefore, we must continue with this dose and frequency of irrigation while the weather is the same. If they are soils composed mainly of sand, it will be necessary to consider the rapid drainage that it may have.

FROM 30 TO 60 CENTIBARS:

We find a floor that begins to ask for a dose of water. Even the plants are not “thirsty” and are able to absorb a certain amount of water, but we must not be careless.

FROM 60 TO 80 CENTIBARS:

A soil that must be watered for most plants. There is still water available for the plants, but the levels will drop in no time.

> 80 CENTIBARS:

Soil with strongly retained water and where water must be provided that can be easily absorbed by the crops.

LET’S TALK ABOUT PRICES AND DEVICES

As for price there is no standard, although we can divide between those dedicated to the hobbyist sector and professionals , those that are installed in highly specialized greenhouses and that provide a lot of highly reliable data.

As we have seen online, there are more than € 500 for professional levels, and less than € 20 for amateurs. If you hurry, there are less than € 10. Curious, especially to do tests and experiments in your garden.

And to finish we leave you the following photo. An application where you control the humidity level of your entire garden through your computer or tablet and decide when to activate irrigation based on it. We will investigate on this!