Salinity in intensive and superintensive plantations is one of the problems encountered by the farmer. We will try to explain it and how to avoid it.

The control of the salts of a land is known as " edaphic study ". Edaphology is a branch of science that studies the composition and nature of the soil in its relationship with plants and the surrounding environment.

What is salinity?

Salinity in soils is contamination by soluble salts . Salinization is measured by the concentration of salts in a given area.

The most common salts are:

  • Chlorine, sulfate, nitrate and bicarbonate ions.
  • Cations of sodium, calcium, potassium and magnesium.

The excess of these salts reduces the development of plants in general and can even make the land unproductive. The saline stress that occurs influences:

  • Photosynthesis influencing its growth.
  • In its germination and outbreaks.

It is a serious problem for agriculture and intensifies intensive crops due to increased irrigation if it is not controlled.

To calculate the amount of salts we measure:

  • Electric Conductivity (EC).
  • Also the Exchangeable Sodium Percentage (ESP).
  • The Sodium Absorption Reaction (SAR).

The conductivity increases with the amount of salts.perdida de producción por Salinidad en plantaciones

As the angle is greater, its slope increases that we can easily calculate with the calculator with the «tan» key. If the slope is greater than one, the crop begins to lose productivity.

With salinity the soil is compacted and the ability to absorb water through the root system decreases.

Salinity does not affect all crops equally and is usually classified as:

  • Sensitive.
  • Moderately sensitive
  • Moderately tolerant.
  • Tolerant

How is salinity produced in intensive and superintensive plantations?

  • It may be due to the presence of salt rocks, but it is usually because of the type of water used, especially in coastal areas that seawater seeps into the aquifers. Therefore the first thing that interests us is an analysis of irrigation water. The fewer salts you have the better.
  • It can also be due to poor irrigation management in intensive and superintensive production of olive trees and others crops and improper use of fertilizers.

Irrigation in areas of extreme heat is not absorbed 100% by the plant, the heat causes some of the irrigation water to evaporate and the salts remain in the environment of the plant because the salts do not evaporate.

This problem is exacerbated if the risks are abundant and distanced in time. In turn, the plant can suffer water stress due to lack of water in the period that is not irrigated. When it receives irrigation, it is not able to absorb the salts that accumulate between them.

At this point the soil composition is also involved. A study of the land is necessary to combine the distancing of the risks and the amounts that we must contribute. The more clay more problem.

Excess salts and where they accumulate

  • First we see with the scheme how irrigation forms the wet bulb and on the surface part the water evaporates the wider the area is and there is more heat. The amplitude of the wet bulb depends on the type of terrain. As it is more clayey, it is wider and therefore results in more evaporation.
Esquema de riego
Esquema de riego

BULBOS HÚMEDOS SEGÚN TIPO DE SUELO

  • Secondly, we analyze how salts accumulate when watering is very abundant and distant. Evaporation causes the salts to accumulate in the wet bulb and around the roots of the plant.
Esquema de Salinidad en plantaciones
Salinity scheme in plantations
  • Thirdly and once we look at the problem, one of the solutions is to wash the area, but this causes the salts to move from the wet bulb, but not to disappear. If the soil is also clayey, the accumulation will make a plate of salts that ends up being very harmful to the plantation and in the long run to the ground. The more sandy, the more the salts are filtered with the washes.
  • Finally, recommend that in case of rain, drip irrigation should be maintained to prevent surface salts from going to the root zone. It is a way to have the bulb isolated from excessive salts.

Classification of soils affected by salts

tipos-de-suelos-según-Salinidad en plantacionesEffects of salinity on crops

  • The main one is the sealing of the pores of the soil, preventing nutrients from moving.
  • The pools that negatively affect most crops as we have indicated in other articles.
  • Root suffocation prevents root growth and normal lengthening that can lead to serious plant problems.
  • Stomatal closure, a serious problem that leads to impaired perspiration and concentration of carbon dioxide.

Salinity solutions in intensive and superintensive plantations.

To avoid salinity and distance washes or not having to reach them, it is best to make short and frequent waterings.

The Plantae sensors indicate the degree of humidity and conductivity in real time and therefore the need for irrigation and the risk of salts. In this way there are no drying intervals around the plant besides absorbing it in a more continuous way and this causes that with the evaporation the salts accumulate much less.

To all this we can add a padding that prevents evaporation.

In cases of excessive accumulation, drainage can be done with ditches that receive the salts when washing.

Other solutions

At present, different Universities carry out studies on in vitro embryo cultures that are resistant to salinity, especially of the olive tree. The Picual variety is quite resistant to salinity but other varieties such as chamomile are more sensitive.

Studies in the creation of these plants in vitro in nursery can shorten the problem and if it is also accompanied by a control, the effect of salinity in the short and long term can be minimized. There are also studies that indicate that in the first years salinity does not affect growth or production but in the long term a significant decrease in growth and fruit is accused.

The intensive and superintensive olive varieties are usually Arbequina and Arbosana that in traditional cultivation are not usually sensitive to salinity because irrigation is scarce. When the crop is intensive or superintensive, irrigation in times of heat intensifies and the problem appears if we do not control it properly.

Therefore, the control by humidity sensors, in addition to saving water and energy, will reduce salinity and therefore the production and duration of plantations is favored.

Olivos superintensivos controlados por sensores Plantae
Super-intensive olive trees controlled by Plantae sensors
Sensores midiendo la humedad y Salinidad en plantaciones a distints profundidades
Sensors measuring humidity at different depths indicate in real time the degree of humidity of the olive tree
Plantación de frutales superintensivas
Plantation of super-intensive fruit trees in Algeria controlled by Plantae
Viñedos con riego por goteo con sensores Plantae
Vineyards with drip irrigation
Cítricos con sensores Plantae
Citrus with drip irrigation controlled by sensors