

The utilization data of RAINCATCHER that you will find in the different parts of this section are generic data: our specialists can direct you towards a use adapted to your horticultural or agricultural needs.
You will find in the chapter "AGRICULTURE AND IRRIGATION" a broad explanation of the possibilities of the use of the RAINCATCHER and its principle of operation.
The other chapters will show you how to use RAINCATCHER on a daily basis in the different fields of activity.
We will soon be giving access to the download of an automatic dosage , simulation tool from RAINCATCHER to apply.
To adapt the dosages of RAINCATCHER to your plants, it is necessary to take into account three important elements which constitute the terrain: the soil, the climate and the type of culture.
Each of these elements has a direct influence on the water requirements and therefore on the dosages of RAINCATCHER to be used to obtain an optimal growth yield in the plant.
Below, we present some lines of thoughts and concepts to take into account to help you optimize your horticultural and agricultural yields.
At the end, we present you the solution RAINCATCHER and the gains brought to the irrigation of your cultures.
Soil is an important element to consider when using RAINCATCHER.
Let’s consider the different types of soils:
Sandy soils are mostly found near bodies of water or in desert climates and are often dry, poor in nutrients and very draining.
Their draining characteristic does not allow a satisfactory retention of water from plant roots. In the same way, they are scarcely (if at all) capable of transporting water from the deep layers by capillarity, and to retain it.
This type of soil requires increasing the amount of RAINCATCHER used to:
We recommend using 2g of hydrogel per kg of soil to retain moisture twice as long as untreated soil.
These soils differ from sandy soils in their ability to form a crust, which is often very hard.
If they are too worked, they can become compact which reduces the infiltration capacity of the water during wet periods.
It is therefore advisable to apply RAINCATCHER during the tillage period and to water it abundantly within 15 days after plowing so that our product hydrates before the crust is formed under the action of the sun.
These soils are different from the previous ones because they can be subject to a very hard crust. The crust is so hard that it becomes difficult to destroy.
With a low rate of clay and organic matter, the formation of aggregates is often poor, which is a brake on the supply to roots of essential materials for their good development.
RAINCATCHER promotes good aeration for this type of soil because of its cyclic changes of physical forms under the action of water.
These soils have a good ability to carry water by capillarity from the deep layers, but the diffusion is slow and does not cover the entire water requirements of plants.
The color of these soils is darker and their aggregations are more distinct. Aggregation decreases the risk of crust formation.
Heavy clays have a high water-retention capacity, but most of this water is tightly bound and unavailable to plants.
The humus content is often higher than that of other mineral soils. They do not form a crust.
The more clay in the soil, the more likely it is to maintain the irrigation water near the roots because it will flow less by gravity than in sandy soil for example.
In this case, the main function of the RAINCATCHER will no longer be to maintain the water around the roots, but to promote a stable water supply to avoid any water stress during a drought, for example. simply to optimize irrigation on a very greedy water culture.
This is determined by the size of the soil particles and their respective proportions. Recall the dimensions of the three categories of soil constitutive particles:
The structure of these particles can be compact or aggregated. In the latter case, the particles are bonded together while having spaces allowing the transport of oxygen and carbon dioxide to the roots.
The water content is a function of the porosity and permeability of the soil. The maximum volume of water that a soil can hold is the "field capacity" FC, or soil holding capacity that depends on its particle size.
The aggregation of particles by RAINCATCHER amplifies its work as a water retainer because the notion of Total Water Available increases automatically with the aeration of the soil.
Remember that good oxygen aeration also allows a better decomposition of the fresh organic matter, a better life of the anaerobic soil and a better installation and development of the plant notably via the facilitated contribution in ferrous materials.
Climates condition by the volumes of precipitation and by induction, the types of soils.
The place and the type of soil of the location where RAINCATCHER will be used will be, of course, a determinant, but it will also be necessary to specify the type of climate according to the region and / or the latitude: in a country like France, one can find several types of climates that have a direct influence on the types of soils and geology they have carved for centuries.
The effects of global warming will also affect the dosage of RAINCATCHER to be used, depending on the occasional occurrence of drought events and precipitation characteristics (spacing of violent showers punctuated by significant temperature rises).
In the soil, water can be divided into 3 states:
A plant that will leave the area of the TWA, either because of soil too waterlogged (or too much moisture in a greenhouse), or because of a drastic drying, will perish respectively by asphyxiation or wilting.
The volume of water available to plants, expressed in millimeters per centimeter of soil depth and called the Total Water Available TWA, therefore includes the “Ready Available Water” RWA and the “Management Allowable Depletion” MAD or "Survival Reserve".
The TWA is, as its name suggests, a reserve that must be regularly replenished to prevent the plant moving into water stress.
The TWA depends on 2 parameters: the soil depth colonized by the root system (about 1 m for an annual wheat or maize crop) and the soil texture.
For a depth of 1 m, useful reserve values are obtained ranging from 70 mm of water for coarse sandy soil, to 200 mm of water for loam-clay soil.
The root volume varies according to the plants. We can divide the vegetable plants in 3 groups according to their rooting:
As an indication, the average value of the TWA is:
The texture of the soil has a direct influence on the UK:
Other important points:
The Texture Triangle is used to estimate the TWA by soil type. The TWA is expressed in millimeters of water per centimeter of fine soil (particles less than 2 mm in size).
From the experiments we have done, we know that RAINCATCHER increases the TWA from 30% (very clayey soil) to 70% (fine sand soil).
Plants can never extract all the water from the soil because the root capacity differs according to the type of plant and the roo volume. The plants use only part of the TWA: The Ready Available Water.
The RAW of a soil is also expressed in millimeters of water per cm of fine soil. It is difficult to estimate, but can be estimated at 60% of the TWA in the absence of precise analysis and at least half of the hydrated RFU should be maintained to avoid water stress.
SMC | |
---|---|
Sand | 0.7 |
Loamy sand | 1 |
Sandy loam | 1.45 |
Loam | 1.8 |
Sandy clay loam | 1.75 |
Sandy clay | 1.7 |
Clay | 1.7 |
Silty clay | 1.8 |
Clay loam | 1.95 |
Silty clay loam | 1.8 |
Silty loam | 1.75 |
Silt | 1.3 |
For a low to medium stony soil over a horizon of 80 cm deep (= depth of colonizing roots) composed of:
Calculation of the TWA and the RAW on this horizon:
According to the Texture Triangle and the associated coefficients, this horizon corresponds to a fine silt soil in the first 30 cm and a clay loam soil in the 50 cm below.
On 80 cm, the total TWA is therefore 47.25 + 48.75 = 96 mm.
The RAW of the horizon is therefore = 96 X 0.60 = 57.6 mm.
Considering the properties of this soil, the application of RAINCATCHER increases its TWA by 55%.
The permeability (k) of a soil is defined by the rate of infiltration of water into the soil; k is measured by Darcy's law:
A layer is deemed impervious for values of k of the order of 9 - 10m / s. The water that falls on the soil surface begins to moisten the upper part of the soil (for a few centimeters): part of which is evaporated directly during and after the rain.
With the warming of the climate, natural irrigations have become increasingly outdated and are often applied to dry soils and the type of soil, that holds a coefficient of permeability limiting the penetration by gravity.
The plant receiving large amounts of water in a short time is not able to take advantage of this excess of abundance.
In case of abundant rainfall and depending on the region, we also take into account the coefficient of permeability in the RAINCATCHER assay. During these showers, RAINCATCHER will rebuild its reserves with the little water that will seep into the soil and hold for several weeks this water that the plant will not be able absorb for a short time.
he water balance provides elements for the calculation of irrigation dosages, it is based on the knowledge and data of ETo (Reference Evapotranspiration) and TWA (Total Water Available).
Evapotranspiration ET = sum of water evaporated by soil and plant: ET = EV + T
Evapotranspiration is the combination of two phenomena of water discharge: the evaporation of water (EV) in contact with the plant under the climatic action on the one hand, and the transpiration (T) of it on the other hand.
This phenomenon could be compared to humans, who need to drink water to live. The more effort a person makes, and depending on their growth phase, the more water they need (there is evidence that the stomata of the leaves of the plant open and close according to the wind, which is why the effect of the latter partially increases the ET).
If we took two immobile individuals, one sitting under the sun in the desert and another sitting in a humid forest, we would also understand that the perspiration of the one in the desert would be more important and that the individual sitting in the forest would have substantially more water reserves provided by the ambient humidity.
The same is true for plants: the roots of plants draw water from the soil's valuable reserve and disperse it into the atmosphere through ET evapotranspiration via their intrinsic perspiration and the evaporation of water under effect of heat. Each plant, just like every living being, has specific water needs:
Type of crop | Water need* | Sensibility to drought |
---|---|---|
Alfalfa | 800-1600 | low-medium |
Banana | 1200-2200 | high |
Barley / Oats / Wheat | 450-650 | low-medium |
Bean | 300-500 | medium-high |
Cabbage | 350-500 | medium-high |
Citrus | 900-1200 | low-medium |
Cotton | 700-1300 | low |
But | 500-800 | medium-high |
Melon | 400-600 | medium-high |
Onion | 350-550 | medium-high |
Peanut | 500-700 | low-medium |
Peas | 350-500 | medium-high |
Pepper | 600-900 | medium-high |
Potato | 500-700 | high |
Paddy field | 450-700 | high |
Sorghum / Millet | 450-650 | low |
Soy | 450-700 | low-medium |
Sugar beet | 550-750 | low-medium |
Sugar cane | 1500-2500 | high |
Sunflower | 600-1000 | low-medium |
Tomato | 400-800 | medium-high |
*mm/total crop period
Plants are living creatures that consume water for their growth and it is important to help them settle after planting. We must follow the watering the first 15 days to allow them to avoid later problems such as the "black ass" for tomatoes or peppers.
The quality of the plants has an influence on the resistance to drought: old plants will emit fewer roots and therefore have a lower resistance to drought (squash, salads in particular).
It is also very important that RAINCATCHER receives a normal initial watering to build up its reserves. Subsequently, it replenishes these reserves with each irrigation to counter the losses due to evaporation which will result in a significant water saving.
It is possible to apply RAINCATCHER directly in its gel form: this process is used for special needs such as tree transplantation and allows for an exceptional transplant success rate.
Throughout the growth of the plant, the water needs will be different and they can be quantified according to:
As an example, for a crop grown in a hot climate:
Specy | K Initial | K Max | K Final |
---|---|---|---|
Tomato | 0.2 | 1.4 | 1 |
Cucumber | 0.2 | 1.2 | -- |
Melons | 0.2 | 1.3 | 1.1 |
Vegetables do not have the same needs according to their stage of cultivation. For example, for the tomato, the ETc reaches a maximum at the 4th bouquet in flower or at the 1st fruit maturing ie turning to red.
But beware, if you water too much at maturity, the fruits burst, hence the use of RAINCATCHER which will accompany the plant in its ETc according to its needs. Similarly, pumpkins will be supplied with water only at their request: their conservation will be better.
Effective Rooting Depth of Mature Crops for Irrigation System Design
Let's take an average plant with a depth of rooting of 20 cm in a soil of loams to the TWA of 1.8.
The TWA of the horizon will be (1.8 x 20) x 0.6 = 21.60 mm
With an ET= 4mm / day, the soil water reserve for the plant will then be 21.6 / 4 = 5.40 days.
We usually apply a correction of 80% in desirable water supply (excluding salad): 5.40 / 0.80 = 4.32
This results in about 4 to 5 days of reserve for a plant rooted at 20 cm.
ET varies considerably depending on meteorological parameters such as wind, sunshine and heat. On average, we consider the values of the following table:
ET in mm according to climate:
Mean daily temperature
Climatic zone | low (less than 15°C) | medium (15-25°C) | high (more than 25°C) |
---|---|---|---|
Desert/arid | 4 to 6 | 7 to 8 | 9 to 10 |
Semi-arid | 4 to 5 | 6 to 7 | 8 to 9 |
(Moist) Sub-humid | 3 to 4 | 5 to 6 | 7 to 8 |
Humid | 1 to 2 | 3 to 4 | 5 to 6 |
The values in the table above, which only take into account heat, are therefore only indicative and show that the ET can vary twice for an average ΔT of 20 °. Irrigation water evaporates very quickly on hot soil and at high temperatures, whether on the surface or in the soil. The heat increases in parallel the perspiration of the plant but in lesser proportions.
It is also necessary to increase the ET by 10 to 20% in windy regions.
By compiling all the theses that have been made on the ratio Perspiration / Evapotranspiration, we also find that the Latitude of the place of culture has an influence on the ET varying the perspiration of 30 to 70% by following the gradient of increase heat.
It is very easy to understand that the use of the RAINCATCHER, in addition to its direct effect on the increase of the TWA, will greatly reduce the ET in its "evaporation" effect because the water stored and necessary for the plant is between 5 and 10 cm underground, or even deeper with the development of roots that will bind to the gel nodules. Due to low exposure to sunlight and surface soil, RAINCATCHER will maintain its water efficiency longer than untreated soil. In addition, RAINCATCHER is in a solid state and will, by definition, require a greater amount of energy than water in the liquid state to turn into gas and thus evaporate.
With RAINCATCHER, we must separate the terms "evaporation" and "perspiration". The "evaporation" effect will only occur via the warming of the earth, which decreases with depth. It is the Perspiration of the plant which, by drawing in the available reserves, will influence mainly the value of the ET under the action of the RAINCATCHER.
From our experiences, we know that the ET and therefore the ETc, is decreased under the effect of RAINCATCHER a value of between 20% to 40% depending on the climate.
RAINCATCHER has an undeniable effect on crop growth.
1mm of precipitation corresponds to 1 liter on 1 m2.
Take the soil:
This soil has a TWA of 57 mm over a horizon of 80 cm, so a water requirement of 570 m3 of water per hectare (1 mm = 10 m3 / ha) to be replenished.
From our proving experiments, we know that RAINCATCHER increases the TWA of this soil by 55%, which means that the TWA after application of the RAINCATCHER is raised to 88 mm.
Maize requires 500 to 800 mm of water throughout its growing season, which means that it must replenish 9 to 14 times the TWA of this type of soil over the period.
At latitude 45, under a subtropical climate (hot and long summer) between April and September, it needs 500 mm of water with the following ETc (mm):
APRIL | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
---|---|---|---|---|---|
11.9 | 77.7 | 109.5 | 187.6 | 112 | 16.9 |
We estimate at -30% the influence of RAINCATCHER on the ET (and thus the ETc) under this type of climate.
We thus extrapolate this table which matches the new TWA of the ground vis-à-vis the ETc under the action of RAINCATCHER, by considering a complete TWA following a consequent watering after application of the RAINCATCHER:
RAINCATCHER | APRIL | MAY | JUNE | JULY | AUGUST | SEPTEMBER |
---|---|---|---|---|---|---|
ETc mm | 8.3 | 54.4 | 76.6 | 131.3 | 78.4 | 11.83 |
TWA mm | 88 | 88 | 88 | 88 | 88 | 88 |
BALANCE WATER mm | 79.7 | 25.3 | 8.7 | 7.4 | 9 | 7.17 |
IRRIGATION mm | 0 | 60 | 130 | 80 | 10 | -- |
The total irrigation to be provided with the RAINCATCHER APPLICATION will be 280 mm, giving a saving of 54% in water.
The application of RAINCATCHER will be 15 to 100 kg per hectare depending on the terrain.
Our specialists will make a personalized study and advise you on the ideal dosage to apply according to your parameters. We will soon be providing our customers with an online simulation tool to tell you the earnings generated by using the RAINCATCHER.
Application | Sandy Soil | Mud Soil | Clay Soil |
---|---|---|---|
Beans | 35 kg / ha | 20 kg / ha | 16 kg / ha |
Carrots | 30 kg / ha | 18 kg / ha | 12 kg / ha |
On the left, the biggest of the tomatoes pushed with RAINCATCHER, on the right the biggest of the tomatoes pushed without:
A simulation tool for professionals will soon be available online to calculate the various parameters you need:
Input parameters:
Output parameters: