Irrigation of horticultural plants using sea water directly is possible, according to a study by the Aqua Maris Foundation, as reported by Hortoinfo.
The study highlights that, when we talk about water, we often assume that we are dealing with fresh water, "making the mistake of marginalising sea water, which accounts for 97 percent of all water on our planet."
Aqua Maris stresses the fact that fresh water only accounts for 3 percent of the total, and of this we only have access to about 0.06 percent, because the rest is in glaciers, deep aquifers, icy land and in the atmosphere.
70 percent of the little fresh water that we have access to is consumed for irrigation, another 20 per cent is used for industrial processes and only 10 percent goes to domestic consumption.
Given the lack of the necessary fresh water to obtain the nutrients to feed humanity in the near future, Aqua Maris and other organisations are pushing for sea water, the most widely available, to be granted its rightful position, not only for use as drinking water (which is or can be) but also as a great source for minerals.
Basic principles
If we observe nature with care and perspective, we can see that we are being given the key to the issue of irrigation. Forests and meadows, unlike private gardens or fields devoted to agriculture, can hold their greenness without rain for months. The key is in the land, in groundwater and aquifers that store and manage water in a very efficient manner, with river basins distributing underground water and watering indirectly in their path from the mountains to the sea.
But irrigation (from above) is the method that humanity has chosen to hydrate plants and thus give them life, imitating the model that was clearer to the open eye: the rain. Throughout history, experimentation has always been based on the premise that water had to come from above, so it has always gone in the same direction. And of course, most attempts made to irrigate with sea water have been carried out following the general models, with disastrous consequences. Plants burned, and even if they managed to thrive with sea water, eventually the ground would become saturated due to the high accumulation of salt, thus rendering it dead and useless for any crop.
Historically, the sea has irrigated areas near the coast, reaching deeper underground and keeping the underground always wet, acting in the same way as river aquifers.
The example of islets
Another situation that can be observed in nature is that where we see plants not classified as halophytes being watered only with sea water. We speak of those islands we see in countless photographs, which force us to conclude that all the vegetation is sustained by irrigation with sea water. Plants with a greater ability to take advantage of sea water are in the areas closest to the sea, while the others are closer to the centre and at higher elevations, making use of the continuous underground moisture provided by sea water.
Conclusion
Aqua Maris reached the conclusion that the two methods considered most efficient for irrigation with sea water, and in which their research has focused, are those taking place in nature: the creation of a water table with sea water to keep the underground wet, or adapting plants, like chards, to the salinity of sea water, cultivating them in a soil that has the ability to drain excess salts.
The experiments
Different experiments have been conducted over time, seeking to make irrigation with sea water possible. Carmelite monks in Sestao, already in the seventeenth century, achieved excellent results with the cultivation of all kinds of vegetables in sandy soil using sea water. In the present, we have the case of the barren fields in Eritrea, where the cultivation of salicornia has turned the region into a real garden.
Scientists at Aqua Maris point out that "our experiments are mainly focused on groundwater irrigation systems, and consequently we are more interested in trying to understand the behaviour of water and minerals underground that are in the type of plants we grow."
Irrigation exclusively with seawater
This is a garden created in 2006 with the basic principles of irrigation using groundwater. In the 7 years since its creation, it has always remained green. It is evident that you can really use sea water to irrigate crops or gardens.
"We still have much to learn and test, but we have already got rid of the myth that sea water kills plants. The important thing is to learn how to use it and become familiar to how it works for different types of soil," say the researchers.
In an experiment carried out with a three-level device to check the performance of the same species at different distances from water it was observed that the most important aspect is not the plant itself, but the ground.
"In this test, we found that the same type of rocket seed showed a completely different growth development depending on the level. We should add that the most surprising thing of all was that the taste changed depending on the distance from sea water," stresses the head of the experiment.
The study in Tarrassa
On 20 April, 2014, Andrea Navas, Beatriz Palomares and Carla Miró, three high school students at the college Mare de Deu del Carme of Terrassa, in partnership with the UPC (Universitat Politècnica de Catalunya) and the Aqua Maris Foundation of Badalona, decided to focus their final course work in the study of the potential of the use of sea water to irrigate crops.
The experiment in question was carried out by planting three edible species in two fiberglass tanks. They planted chards, dandelions and cherry tomatoes. The deposits were adjusted to keep sea water always at a given level, in contact with the ground, but without flooding it, by using a drain. The two devices shared the same deep substrate (in contact with sea water) of fine gravel, but the rest of the substrate is different for each device (between 1 and 4 mm). One had a kind of conventional fertile substrate (the one which would be used in any ordinary plantation), and the other was a clay with a very poor content of nutrients.
Each device was subsequently divided into three sections, in which the distribution of gravel substrate varied, using different proportions (25%, 50% and 75%). The purpose of this small-scale experiment was to check the feasibility of the cultivation of these three types of plants watering them only by means of an artificial water table containing sea water. The effect produced by the high degree of mineralisation of seawater (36 grams of salt per litre) in development and in the final composition of the plants will also be checked.
This experiment, combined with others that have been carried out in the past or are planned for the near future, can be used to open new lines of research into the use of sea water for agriculture.
The study highlights that, when we talk about water, we often assume that we are dealing with fresh water, "making the mistake of marginalising sea water, which accounts for 97 percent of all water on our planet."
Aqua Maris stresses the fact that fresh water only accounts for 3 percent of the total, and of this we only have access to about 0.06 percent, because the rest is in glaciers, deep aquifers, icy land and in the atmosphere.
70 percent of the little fresh water that we have access to is consumed for irrigation, another 20 per cent is used for industrial processes and only 10 percent goes to domestic consumption.
Given the lack of the necessary fresh water to obtain the nutrients to feed humanity in the near future, Aqua Maris and other organisations are pushing for sea water, the most widely available, to be granted its rightful position, not only for use as drinking water (which is or can be) but also as a great source for minerals.
Basic principles
If we observe nature with care and perspective, we can see that we are being given the key to the issue of irrigation. Forests and meadows, unlike private gardens or fields devoted to agriculture, can hold their greenness without rain for months. The key is in the land, in groundwater and aquifers that store and manage water in a very efficient manner, with river basins distributing underground water and watering indirectly in their path from the mountains to the sea.
But irrigation (from above) is the method that humanity has chosen to hydrate plants and thus give them life, imitating the model that was clearer to the open eye: the rain. Throughout history, experimentation has always been based on the premise that water had to come from above, so it has always gone in the same direction. And of course, most attempts made to irrigate with sea water have been carried out following the general models, with disastrous consequences. Plants burned, and even if they managed to thrive with sea water, eventually the ground would become saturated due to the high accumulation of salt, thus rendering it dead and useless for any crop.
Historically, the sea has irrigated areas near the coast, reaching deeper underground and keeping the underground always wet, acting in the same way as river aquifers.
The example of islets
Another situation that can be observed in nature is that where we see plants not classified as halophytes being watered only with sea water. We speak of those islands we see in countless photographs, which force us to conclude that all the vegetation is sustained by irrigation with sea water. Plants with a greater ability to take advantage of sea water are in the areas closest to the sea, while the others are closer to the centre and at higher elevations, making use of the continuous underground moisture provided by sea water.
Conclusion
Aqua Maris reached the conclusion that the two methods considered most efficient for irrigation with sea water, and in which their research has focused, are those taking place in nature: the creation of a water table with sea water to keep the underground wet, or adapting plants, like chards, to the salinity of sea water, cultivating them in a soil that has the ability to drain excess salts.
The experiments
Different experiments have been conducted over time, seeking to make irrigation with sea water possible. Carmelite monks in Sestao, already in the seventeenth century, achieved excellent results with the cultivation of all kinds of vegetables in sandy soil using sea water. In the present, we have the case of the barren fields in Eritrea, where the cultivation of salicornia has turned the region into a real garden.
Scientists at Aqua Maris point out that "our experiments are mainly focused on groundwater irrigation systems, and consequently we are more interested in trying to understand the behaviour of water and minerals underground that are in the type of plants we grow."
Irrigation exclusively with seawater
This is a garden created in 2006 with the basic principles of irrigation using groundwater. In the 7 years since its creation, it has always remained green. It is evident that you can really use sea water to irrigate crops or gardens.
"We still have much to learn and test, but we have already got rid of the myth that sea water kills plants. The important thing is to learn how to use it and become familiar to how it works for different types of soil," say the researchers.
In an experiment carried out with a three-level device to check the performance of the same species at different distances from water it was observed that the most important aspect is not the plant itself, but the ground.
"In this test, we found that the same type of rocket seed showed a completely different growth development depending on the level. We should add that the most surprising thing of all was that the taste changed depending on the distance from sea water," stresses the head of the experiment.
The study in Tarrassa
On 20 April, 2014, Andrea Navas, Beatriz Palomares and Carla Miró, three high school students at the college Mare de Deu del Carme of Terrassa, in partnership with the UPC (Universitat Politècnica de Catalunya) and the Aqua Maris Foundation of Badalona, decided to focus their final course work in the study of the potential of the use of sea water to irrigate crops.
The experiment in question was carried out by planting three edible species in two fiberglass tanks. They planted chards, dandelions and cherry tomatoes. The deposits were adjusted to keep sea water always at a given level, in contact with the ground, but without flooding it, by using a drain. The two devices shared the same deep substrate (in contact with sea water) of fine gravel, but the rest of the substrate is different for each device (between 1 and 4 mm). One had a kind of conventional fertile substrate (the one which would be used in any ordinary plantation), and the other was a clay with a very poor content of nutrients.
Each device was subsequently divided into three sections, in which the distribution of gravel substrate varied, using different proportions (25%, 50% and 75%). The purpose of this small-scale experiment was to check the feasibility of the cultivation of these three types of plants watering them only by means of an artificial water table containing sea water. The effect produced by the high degree of mineralisation of seawater (36 grams of salt per litre) in development and in the final composition of the plants will also be checked.
This experiment, combined with others that have been carried out in the past or are planned for the near future, can be used to open new lines of research into the use of sea water for agriculture.
