Salinity in intensive and super-intensive plantations is one of the problems the farmer encounters. We will try to explain it and how to avoid it.
The control of the salts of a land is known as « edaphic study «. Soil science is a branch of science that studies the composition and nature of the soil in its relationship with plants and the environment that surrounds them.
What is salinity?
Salinity in soils is contamination by soluble salts . Salinization is measured by the concentration of salts in a certain area.
The most common salts are:
- Chlorine, sulfate, nitrate and bicarbonate ions.
- Cations of sodium, calcium, potassium and magnesium.
The excess of these salts diminishes the development of the plants in general and can even make the land unproductive. The salt stress that occurs influences:
- Photosynthesis influencing their growth.
- In their germination and sprouts.
It is a serious problem for agriculture and intensifies in intensive crops due to increased irrigation if it is not controlled..
To calculate the amount of salts we measure:
- The Electrical Conductivity (CE).
- Also the Percentage of Interchangeable Sodium (PSI).
- The Sodium Absorption Reaction (RAS).
Conductivity increases with the amount of salts.
As the angle increases, its slope increases, which we can easily calculate with the calculator with the «tan» key. & Nbsp; If the slope is greater than one, the crop begins to lose productivity..
With salinity the soil compacts and the ability to absorb water by the root system decreases.
Salinity does not affect all crops equally and is usually classified into:
- Moderately sensitive.
- Moderately tolerant.
How is salinity produced in intensive and superintensive plantations?
- It may be due to the presence of saline rocks, but it is usually due to the type of water used, especially in coastal areas, where 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 productions intensive and superintensive of olive trees and other crops and the improper use of fertilizers.
Irrigations in areas of extreme heat are not 100% absorbed by the plant, the heat causes part 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 irrigations are abundant and separated in time. In turn, the plant can suffer water stress due to lack of water in the period when it is not watered. When he receives the irrigation, he is not able to absorb the salts that accumulate between them.
The composition of the soil also intervenes at this point. A study of the terrain is necessary to combine the spacing of the irrigations and the amounts that we must contribute. The more clay the more problem.
Excess salts and where they accumulate
- First we see with the scheme how irrigation forms the wet bulb and in the superficial part the water evaporates the wider the area and the more heat there is. The amplitude of the & nbsp; wet bulb & nbsp; depends on the type of terrain. As it becomes more clay, it is wider and therefore leads to more evaporation..
- Secondly, we analyze how salts accumulate when irrigation is very abundant and far apart. Evaporation causes salts to accumulate in the wet bulb and around the roots of the plant..
- Thirdly and once we observe 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, in addition, the soil is clayey, the accumulation will make a plate of salts that ends up being very harmful for the plantation and in the long term for the land. The more sandy, the more the salts are filtered with the washes.
- Lastly, recommend that in case of rain, drip irrigation should be maintained to prevent surface salts from reaching the root zone. It is a way to have the bulb isolated from excessive salts.
Classification of soils affected by salts
Effects of salinity on crops
- The main one is the sealing of the soil pores, preventing nutrients from moving.
- The waterlogging that negatively affects most crops, as we have already indicated in other articles.
- Root suffocation prevents root growth and normal lengthening, which can lead to serious plant problems.
- Stomatal closure, a serious problem that leads to impaired perspiration and anhydride concentration carbonic.
Solutions to salinity in intensive and super-intensive plantations.
To avoid salinity and distance washing or not having to reach them, it is best to do short and frequent watering.
Los Plantae sensorsthey 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 drought intervals around the plant in addition to absorbing it in a more continuous way and this means that with 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 salts when washing..
Currently, different Universities carry out studies on embryo cultures in vitro 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 nurseries 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 there is a significant decrease in growth and fruit.
The intensive and super-intensive olive varieties are usually Arbequina and Arbosana, which in traditional cultivation are not usually sensitive to salinity because irrigation is scarce. When cultivation 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 favor the production and duration of plantations.