Mix Fertiliser Yourself
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Cultivation problems
The plants are grown before aquaponics or hydroponics. Here are some tips from regular horticulture.
Cultivating plants is not that difficult. Nevertheless, various mistakes are made, especially for beginners, which is why the cultivation is not satisfactory. Of course, this is bad for your wallet because some types of seeds are quite expensive, and it is also bad for the psyche if the little baby plants do not sprout as previously hoped. Possible consequences are that the desire for your own cultivation is quickly lost and that early young plants (sometimes hybrid varieties) are used.
So that this does not happen and the motivation for your own cultivation continues to flourish, we would like to show the 5 most common mistakes in cultivation and how they can be avoided with simple means.
Too many nutrients
Probably the most common mistake in growing is the choice of substrate in which the seeds should germinate. Usually for cost reasons, growing earth is dispensed with here and the commercially available potting soil is used instead. However, this potting soil is pre-fertilized and therefore full of nutrients.
Neither the seeds nor the small seedlings need this nutrient boost. At this stage, they basically only need two factors: light and water.
It is also helpful to have a solid but not pressed substrate in which the seedlings can form the first roots. This substrate should be free of nutrients or at least low in nutrients. So at least the commercial breeding earth.
However, we did even better with Kokoshumus. This coconut is free of nutrients, has a mold-inhibiting effect and stores water much better than potting soil.
Too little or too much water
Both mistakes are often made – either too little or too much water. Either completely dry or the whole pot or container is under water. An almost constant wet environment is rarely created.
After trying out several options for growing ( potting soil, growing soil, cotton wool, and much more. ), a method has gradually emerged with a clear lead in terms of yield technology.
We use or recycle the plastic trays, which contain fresh fruit and vegetables in the supermarket. For example, arugula, spinach, but also strawberries and grapes are usually sold in these bowls. In most households, these bowls end up in the yellow sack, but with us they are collected and reused for cultivation. Advantage: They are available free of charge and they are transparent – so you can regularly check from the side how moist the substrate is.
About two thirds of the coconut mentioned above is filled into these plastic trays. This Kokushumus stores the water particularly well. Pouring during germination is usually not necessary. Pour on once, plastic film over it, done. A biological microclimate is created inside using the plastic film.
Critics will of course monetize the amount of plastic and / or coconut used, but from our point of view this variant is still recommended. All three components, both the humus and the bowls and the film, can be used again and again. Of course, this is not the 100 percent perfect and most environmentally friendly variant in the world, but compared to many other environmental sins that happen on this planet every day, this is a variant that can be reconciled with your own conscience.
Too little light
The third very popular mistake in growing is the lack of light that the freshly germinated plants urgently need. If this light is missing or not sufficiently available, a phenomenon can be observed that is referred to as a distribution.
When it comes to fermentation, the plant does not grow properly, but forms an extremely long but thin shoot to get to the desired light. In rare exceptional cases, the plant later manages to recover, but usually a healed plant will die after a week or two at the latest.
So it is extremely important to provide enough light as soon as the first seedlings are visible. We have the best experience with so-called growing lamps. Grow Lights) made over the plastic trays. While this puts a strain on your wallet as an initial investment, the plants will thank you.
Unfortunately, the growing lamp that we would like to recommend is no longer available for purchase. As soon as we have another recommendation ready, it will be added here.
Too cold
An environment that is too warm or even hot is also a possible mistake, but rather rare.
It is much more common that the cultivation takes place in a much too cold environment. With us, cultivation is generally carried out in the house or in a room that has relatively constant temperatures between 20 and 22 ° C. Few plants need it a little warmer or colder.
If it is desired that the cultivation takes place in the greenhouse, then I recommend thinking about methods to warm the greenhouse and keep the temperatures constant. In Germany, temperatures can still drop below freezing at night in May. Sometimes shining sunshine during the day, but still shivering at night. In any case, it is generally important to wait for the so-called “ Ice Saints ” to put young plants outside.
Sown too tight
If you have not prepared the young plants individually but plan to spicy them with the appropriate development, you should remember not to make the sowing too narrow. Although it is sometimes a real effort to distribute the small seeds individually, care should still be taken.
The young plants need space to develop, need light, which they may take away from each other if they sow too closely, and at the latest when they spike, it takes revenge when knotted roots tear off.
We recommend a distance of at least two centimeters from the respective seed when sowing. Of course, this does not have to be measured exactly with the linear, but if you keep about a thumb width, you are on the safe side. This method can also be used to wonderfully count which seeds are actually germinated and thus calculate the germination rate.
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Fertiliser
Fertiliser programmes
First of all: If you receive a fertiliser recommendation without having explained exactly which plants you are growing, you can safely ignore such recommendations. There are not hundreds of fertiliser types because there is one answer.Each plant species has individual nutrient requirements that also differ according to the growth phase it is in. Furthermore, indiscriminate fertilising, over-fertilising, under-fertilising, wrong composition etc. can have devastating consequences for many plants, ranging from undersupply to specific plant diseases. In order to achieve the best nutrient mixture for a specific plant, there is no getting around an analysis of the plant itself. For cost reasons alone, we recommend preparing the nutrient composition yourself.Mixing hydroponic fertiliser yourself ?
The commercially available fertilisers consist of a complete fertiliser supplemented with macronutrients. They are offered by some hydroponics and/or fertiliser companies and vary depending on the hydroponic plant. An example of a fertiliser programme is the hydroponic tomato programme offered by Hydro-Gardens.
In this programme, growers purchase Hydro-Gardens Chem-Gro tomato formula. It has a composition of 4-18-38 and also contains magnesium and micronutrients. To make a nutrient solution, it is supplemented with calcium nitrate and magnesium sulphate, depending on the variety and/or growth stage of the plant.
Advantages of fertiliser programmes
Programmes like these are easy to use. Minimal ordering of fertilisers is required (only 3 in the Hydro-Gardens example).
Very little or no mathematical calculations are required to prepare nutrient solutions.Disadvantages of fertiliser programmes
Fertiliser programmes do not allow for easy adjustments of individual nutrients. For example, if the leaf analysis shows that more phosphorus is needed. When using a fertiliser programme exclusively, it is not possible to simply add phosphorus.
Another disadvantage is that fertiliser programmes do not allow farmers to take into account the nutrients already present in the water source. For example, if a water source has a potassium content of 30 ppm, there is no way to adjust the amount of potassium added in the fertiliser programme. And too much potassium can in turn block the uptake of other nutrients.
Fertilizer programs can be more expensive than using
Recipes for the production of nutrient solutions.Mix recipes for nutrient solutions / hydroponics fertilizer yourself
There are also recipes for the production of nutrient solutions. The recipes contain a certain amount of each nutrient to be added to the nutrient solution. They are specifically available for a specific crop and in a variety of sources, e.g. B. at the university advice centers, on the Internet and in specialist journals. One example is the modified Sonovelds solution for herbs (Mattson and Peters, Insidegrower) shown below.Modified Sonneveld recipe / herbs
element concentration Nitrogen 150 ppm Phosphorus 31 ppm Potassium 210 ppm Calcium 90 ppm Magnesium 24 ppm Iron 1 ppm Manganese 0.25 ppm Zinc 0.13 ppm copper 0.023 ppm Molybdenum 0.024 ppm Boron 0.16 ppm It is at the discretion of the breeder which fertilizers he uses to produce a nutrient solution according to a recipe. The fertilizers commonly used include:
fertilizer Dosage, contained nutrients Calcium nitrate 15.5 – 0 – 0.19% calcium Ammonium nitrate 34 – 0 – 0 Potassium nitrate 13 – 0 – 44 Sequestrene 330TM 10% iron Potassium phosphate monobasic 0 – 52 – 34 Magnesium sulfate 9.1% magnesium Borax (laundry quality) 11% boron Sodium molybdate 39% molybdenum Zinc sulfate 35.5% zinc Copper sulfate 25% copper Magnesium sulfate 31% manganese Farmers calculate the amount of fertilizer in thenutrient solution based on the amount of a nutrientin the fertilizer and in amount specified in the recipe.Advantages of nutrient solution recipes
Nutritional solutions allow fertilizers to be adjusted based on the nutrients contained in water sources. An example: A gardener uses a water source with 30 ppm potassium and produces the modified Sonneveld solution for herbs that requires 210 ppm potassium. It would have to add 180 ppm potassium ( 210 ppm - 30 ppm = 180 ppm ) to the water in order to obtain the amount of potassium required in this recipe.
With recipes, nutrients can be easily adjusted. When a leaf analysis report indicates that a plant has iron deficiency. It is easy to add more iron to the nutrient solution.
Since recipes make it easy to adapt, fertilizers can be used more efficiently than in fertilizer programs. Using recipes can be less expensive than using fertilizer programs.
Disadvantages of nutrient solution recipesIt has to be calculated how much fertilizer has to be added to the nutrient solution. (Link to performing calculations). Some people may feel intimidated by the calculations involved. However, the calculations only require uncomplicated mathematical skills based on multiplication and division.
A high-precision scale is also required for the measurement of micronutrients, since the required quantities are very small. Such a scale can be found on Amazon from 30.- €: e.g .: KUBEI 100g / 0.001g.This is about the calculation of nutrient solutions for your own needs
Picture: Boston Public Library is licensed under CC BY 2.0
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Fertilizer & Nutrient Solutions
Use the Homestead Bone Black Fertilizer by Boston Public Library, CC BY 2.0 Here we have created a short introduction to the topic of fertilizer and nutrient solutions, with which you can learn the concept, the basics and also the calculation of self-created nutrient solutions. In the last article you will find a brief overview of deficiency symptoms and how you can recognize and correct them.
Please also keep in mind that the perfect recipe for your own plant requires enormous knowledge, complex technology and a lot of experience. However, for many areas this is not necessary at all. If you, as an entrepreneur, are in competition and have to work to the optimum in order to be profitable, things look different. But this little guide is not aimed at entrepreneurs who need to make money with it. For commercial applications, please do not hesitate to take advantage of our experience, our knowledge and the technology required for this: just ask us - email or phone call is enough.
A brief introduction to fertilisers & nutrients
Fertiliser: Calculation of nutrient solutions
Fertilizer: Calculate a nutrient recipe
Fertilizer: Essential Nutrients, Function, Deficiency and Exces
Common Concentrations in Nutrients
To ensure a highly optimised nutrient supply throughout the entire growth process, you need analytical equipment. Here a short overview and Selection.
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Fertilizer: Calculate a nutrient recipe
By Boston Public Library, licensed CC BY 2.0 Now that you have the two basic equations for the production of nutrient solutions, we want to use them to calculate the amounts of fertilizer required for a nutrient solution recipe.
If you are not familiar with the two equations, read this first: Hydroponic systems: Calculating the concentrations of nutrient solutions using the two equations.
Here is our problem: We want to use a modified Sonneveld solution (Matson and Peters, Insidegrower) for herbs in an NFT system. We use two 5-gallon containers and injectors set to a concentration of 100: 1 and call them storage tank A and storage tank B. How much of each fertilizer do we have to put in each storage tank ?
You may be asking: why two storage tanks? This is due to the fact that certain chemicals in our fertilizer solution react with each other as soon as they come into contact with each other. In all nutrient solutions ( fertilizer mixtures ) you have calcium, phosphates and sulfates - among other things, these three chemicals for all plants vital are. The last two react with calcium and are no longer present in the form we need in our nutrient solution. They connect to each other and fall to the bottom of the container as white flakes ( precipitates ). Therefore, phosphates and sulfates must be kept separate from calcium and, when introduced into the nutrient solution of the ( system, saved from direct mixing by means of a dosing pump or measuring cup ).
Modified Sonneveld recipe for herbs
element concentration nitrogen 150 ppm phosphorus 31 ppm potassium 210 ppm calcium 90 ppm magnesium 24 ppm iron 1 ppm manganese 0.25 ppm zinc 0.13 ppm copper 0.023 ppm Molybdenum 0.024 ppm boron 0.16 ppm These are the fertilizers that we will use. Some fertilizers contain more than one nutrient in the recipe, while others contain only one. Here is a small overview Commercial fertilizer from which you can put together your recipe
Fertilizer Contained nutrients(Nitrogen phosphate potassium and other nutrients)Calcium nitrate 15.5-0-0, 19% Ca (calcium) Ammonium nitrate 34-0-0 Potassium nitrate 13-0-44 Potassium phosphate monobasic 0-52-34 Magnesium sulfate 9.1% mg (magnesium) Sequestrene 330 TM 10% Fe (iron) Manganese sulfate 31% Mn (Mangan) Zinc sulfate 35.5% Zn (zinc) Copper sulfate 25% Cu (copper) Boron 11% B (Boron) Sodium molybdenum 39% Mo (molybdenum) The first thing you notice is that we have three sources of nitrogen (calcium nitrate, ammonium nitrate and potassium nitrate), have two sources of potassium (potassium nitrate and potassium phosphate monobasic) and one source of calcium (calcium nitrate) and phosphorus (single-base potassium phosphate). We can start calculating the calcium or phosphorus in the recipe because only one fertilizer provides each nutrient. Let's start with calcium.
The recipe provides 90 ppm calcium. We calculate how much calcium nitrate we need to use to achieve this by using the first of our two equations.
We need to add 895.3 g calcium nitrate to get 90 ppm calcium. However, calcium nitrate also contains nitrogen. We use the second equation to determine how much nitrogen should be added in ppm.
We add 73.4 mg N / l or 73.4 ppm nitrogen. Our recipe provides 150 ppm nitrogen. If we subtract 73.4 ppm nitrogen from it, we have to add 76.6 ppm nitrogen.
Let us now calculate how much single-base potassium phosphate we have to use to deliver 31 ppm phosphorus.
We need to add 262 g of potassium phosphate monobed to get 31 ppm phosphorus. However, potassium phosphate also contains single-base potassium. We use the second equation to determine how much potassium should be added in ppm.
We add 39 mg K / l or 39 ppm potassium. Our recipe provides 210 ppm potassium. If we subtract 39 ppm of potassium from it, we see that we still have to add 171 ppm of potassium.
We have only one other source of potassium, namely potassium nitrate. Let's calculate how much we have to use of it.
We need to add 885 g of potassium nitrate to get 171 ppm of potassium. However, potassium nitrate also contains nitrogen. We use the second equation to determine how much nitrogen should be added in ppm.
We add 61 mg N / l or 61 ppm nitrogen. Our recipe provides 150 ppm nitrogen. We supplied 73.4 ppm nitrogen from calcium nitrate and had to add 76.6 ppm nitrogen. Now we can subtract 61 ppm nitrogen. We still have to add 15.6 ppm nitrogen. The only source of nitrogen that we have is ammonium nitrate.
Let us now calculate how much ammonium nitrate we have to use to deliver 15.6 ppm nitrogen.
We need to add 86.7 g of ammonium nitrate to get 15.6 ppm nitrogen.
At this point we have completed the nitrogen, phosphorus, potassium and calcium part of the recipe. For the other nutrients, we only need to use the first equation, since the fertilizers that we use for their supply contain only one nutrient in the recipe.
We need to add 498.5 grams of magnesium sulfate to get 24 ppm magnesium.
We need to add 18.9 grams of Sequestren 330 to get 1 ppm of iron.
We need to add 1.5 grams of manganese sulfate to get 0.25 ppm manganese.
It is easier to weigh small amounts of fertilizers in milligrams. The conversion from milligrams to grams is therefore carried out as follows
We need to add 692 milligrams of zinc sulfate to get 0.13 ppm zinc.
We need to add 0.17 milligrams of copper sulfate to get 0.023 ppm copper.
We need to add 2.8 milligrams of borax to get 0.16 ppm borax.
We need to add 0.12 milligrams of sodium molybdate to get 0.024 ppm molybdenum.
Summary:
Element Addition Nutrient Solution Calcium 895.3 g calcium nitrate 90 ppm calcium Phosphorus 262 g of potassium phosphate monobasic 31 ppm phosphorus Potassium 885 g potassium nitrate 171 ppm potassium Nitrogen 86.7 g ammonium nitrate 15.6 ppm nitrogen Magnesium 498.5 grams of magnesium sulfate 24 ppm magnesium Iron 18.9 grams of sequestrene 330 1 ppm iron Manganese 1.5 grams of manganese sulfate 0.25 ppm manganese Zinc 692 milligrams of zinc sulfate 0.13 ppm zinc Copper 0.17 milligrams of copper sulfate 0.023 ppm copper Boron 2.8 milligrams of borax 0.16 ppm boron Molybdenum 0.12 milligrams of sodium molybdate 0.024 ppm molybdenum Now all calculations have been completed. Now we have to decide in which storage tank, A or B, we give the individual fertilizers. In general, the calcium should be kept in a tank other than the sulfates and phosphates, as they can form precipitates that can clog the drip bodies of the irrigation system. Using this guideline, we can put the calcium nitrate in one tank and the monobasic potassium phosphate, magnesium sulfate, manganese sulfate, zinc sulfate and copper sulfate in the other tank. The rest of the fertilizers can be placed in both tanks.
You should also consider the amount of nutrients in irrigation water. For example, if we use irrigation water that contains 10 ppm magnesium, we only need to add 14 ppm more with our fertilizer (24 ppm Mg, which are required in the recipe, minus 10 ppm Mg in water). This is a great way to use nutrients more efficiently and fine-tune your fertilizer plan.
With some micronutrients, you have to decide for yourself what you want to add. You could do a small experiment to find out whether you need to add 0.12 milligrams of sodium molybdate to your stock solution, for example, or whether you are satisfied with the performance of your plants without this addition.
One last point to consider. Sometimes the calculations don't work as well as here for fertilizers that contain more than one required nutrient, and you may need to add more of a nutrient, than is provided in the recipe to provide the other nutrient.
For example, if you apply calcium nitrate to meet calcium needs, the solution may not contain enough nitrogen. In such cases, you have to decide which nutrient you want to give priority to. For example, you could apply calcium nitrate to meet the plants' nitrogen needs because the excess amount of calcium does not harm the plants. Or you choose to apply it based on the plant's calcium needs because the lack of nitrogen is just a few ppm.
Here you will find what problems there may be with a lack and excess of fertilizer
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Fertilizer: Essential Nutrients, Function, Deficiency and Exces
Deficiency symptoms
Before we begin discussing the principles of plant nutrient systems in hydroponic systems, we need to define what we mean by "hydroponic."
Hydroponics is the process of growing plants in water containing nutrients. Examples of this type of hydroponic systems are NFT (Nutrient Film Technique) systems and deep water floating systems where the plant roots are placed in nutrient solutions. Another definition of hydroponics is growing plants without soil. According to this definition, growing plants in soilless media (potting soil) or other types of aggregate media such as sand, gravel, and coconut shells are considered hydroponic systems. Here we use the term hydroponics for growing plants without soil.
Essential nutrients
Plants cannot function properly without these 17 essential nutrients. These nutrients are needed to allow the processes important to plant growth and development to take place. For example, magnesium is an important component of chlorophyll. Chlorophyll (see picture) is a pigment that serves to capture light energy needed for photosynthesis. It also reflects green wavelengths and is the reason most plants are green. Magnesium is the center of the chlorophyll molecule. The table below lists the functions of the essential nutrients for plants.
Essential nutrients can be broadly divided into macronutrients and micronutrients . The classification macro (large) and micro (tiny) refers to the amounts. Both macronutrients and micronutrients are essential for the growth and development of plants. Macronutrients include carbon, hydrogen, oxygen, nitrogen, phosphorus, potassium, sulfur, calcium, and magnesium. Micronutrients include iron, manganese, zinc, boron, molybdenum, chlorine, copper, and nickel. The difference between macronutrients and micronutrients lies in the amount plants need. Macronutrients are needed in larger amounts than micronutrients. Table 1 shows the approximate content of essential nutrients in plants.
Plants obtain carbon, hydrogen and oxygen from air and water. The remaining nutrients come from the soil or, in the case of hydroponics, from nutrient solutions or aggregate media. The sources of nutrients available to plants are listed in Table 1.
Essential components of nutrient solutions, Table 1
Nutrient (symbol) Approximate plant content (% dry weight) Role in the plant
Source of nutrients available to the plant Carbon (C), hydrogen (H), oxygen (O) 90+ % Components of organic compounds Carbon dioxide (CO 2 ) and water (H 2 O) Nitrogen (N) 2–4% Component of amino acids, proteins, coenzymes, nucleic acids Nitrate (NO3-) und Ammoniak (NH4+) Sulfur (S) 0.50% Component of sulphur-containing amino acids, proteins, coenzyme A Sulfate (SO4-) Phosphor (P) 0.40% ATP, NADPMetabolic intermediates, membrane phospholipids, nucleic acids Dihydrogenphosphat (H2PO4-), Hydrogenphosphat (HPO42-) Potassium (K) 2.00% Enzyme activation, turgor, osmotic regulation Potassium (K + ) Calcium (Ca) 1.50% Enzyme activation, signal transduction, cell structure Calcium (Ca2+) Magnesium (Mg) 0.40% Enzyme activation, component of chlorophyll Magnesium (Mg2+) Manganese (Mn) 0.02% Enzyme activation, important for water splitting Manganese (Mn 2+ ) Iron (Fe) 0.02% Redox changes, photosynthesis, respiration Iron (Fe 2+ ) Molybdenum (Mo) 0.00% Redox changes, nitrate reduction Molybdat (MoO42-) Copper (Cu) 0.00% Redox changes, photosynthesis, respiration Copper (Cu 2+ ) Zink (Zn) 0.00% Cofactor activator for enzymesAlkohol-Dehydrogenase, CarboanhydraseZink (Zn2+) Bor (Bo) 0.01% Membrane activity, cell division Borat (BO3-) Chlor (Cl) 0.1–2.0% Charge equalization, water splitting Chlor (Cl-) Nickel (Ni) 0.000005–0.0005% Component of some enzymes, biological nitrogen fixation, nitrogen metabolism Nickel (Ni2+) To get an idea of the quantities required, here is a fertilizer quantity recommendation from the BISZ for sugar beet in arable farming. From the quantity you can see that, for example, 90 grams of copper per 1 ha (10,000 m 2 ) is only a tiny amount per square meter and a fraction of that is needed per plant. In this example: 0.009 grams per square meter. But if this element is completely missing, the plant cannot grow at all because it is essential for photosynthesis (see table above). When dry, it (copper) is no longer found due to chemical processes during drying.Nutrient requirement kg/ha Nitrogen 250 Phosphor 100 Potassium 400 Magnesium 80 Sulfur 20 – 30 Calcium 60 – 80 Nutrient requirement g/ha Bor 450 – 550 Manganese 600 – 700 Ferrum 500 – 1.500 Copper 80 – 90 Zinc 250 – 350
PH value
It is impossible to talk about plant nutrition without considering pH. Hydroponics is primarily concerned with the pH of the water used to prepare nutrient solutions and irrigate plants. pH is a measure of relative acidity, or hydrogen ion concentration, and plays an important role in the availability of plant nutrients. It is measured using a scale of 0 to 14 points, with 0 being the most acidic, 7 being the most neutral, and 14 being the most alkaline. The scale is logarithmic, and each unit corresponds to a 10-fold change. This means that small changes in values mean large changes in pH. For example, a value of 7 is 10 times higher than 6 and 100 times higher than 5. In general, the optimal pH range for growing vegetables in hydroponics is 5.0 to 7.0.This diagram shows the relationship between nutrient availability and pH value:
Graphic: Pennsylvania State University
At the bottom of the chart, various pH levels between 4.0 and 10.0 are indicated. At the top of the chart, the relative acidity or alkalinity is indicated. Within the chart, the relative nutrient availability is represented by a bar. The wider the bar, the more relatively available the nutrient is. For example, the nitrogen bar is widest at a pH of 6.0 to 7.5. This is the pH at which it is most available to plants. Between 4.0 and 4.5, it is very narrow and not as easily available to plants.
It is also important to consider the alkalinity of the water. Alkalinity is a measure of capacity. It measures the ability of the water to neutralize the acid. This is primarily due to the combined amount of carbonate (CO3) and bicarbonate (HCO3), but hydroxide, ammonium, borate, silicate and phosphate can also contribute.
When total alkalinity is low, the water has a low buffering capacity. As a result, the pH changes slightly depending on what is added to the water. When total alkalinity is high, the pH of the water is high. To lower a high pH of the water, acid can be added to the irrigation water. The amount of acid needed depends on the alkalinity of the water.
Nutrient antagonism and interactions
For example, a hydroponic tomato nutrient solution recipe calls for 190 ppm nitrogen and 205 ppm potassium. Due to an error in calculating the amount of fertilizer to use, 2,050 ppm potassium is added. An excess of potassium in the solution can cause antagonism with nitrogen (and other nutrients) and result in nitrogen deficiency even if 190 ppm nitrogen was added. The table below lists common antagonisms.
Nutrient Antagonist of Nitrogen Potassium Phosphor Zinc Potassium Nitrogen, calcium, magnesium Sodium Potassium, calcium, magnesium Calcium Magnesium, Bor Magnesium Calcium Ferrum Manganese Zinc Ion competition: high concentrations of heavy metals, copper and phosphate reduce the uptake rate of zinc: the cause of zinc deficiency in the plant does not necessarily have to be zinc-poor soil See also: Interactions
Problems with nutrients
Hydroponic systems are less forgiving than soil-based systems, and nutrient problems can quickly lead to plant problems. This is why nutrient solution composition and regular monitoring of the nutrient solution and plant nutrient status are critical.
The minimum law
Carl Sprengel's law of the minimum states that the growth of plants is limited by the resource that is relatively scarce (nutrients, water, light, etc.). This means that a lack of nitrogen can also lead to the plant not being able to process other nutrients. On the other hand, too much of one component can have undesirable consequences: for example, too much lime inhibits the absorption of nutrients.
Also pay attention to the symptoms ofDeficiency symptoms that often point out problems:Here is a brief overview of the deficiency symptoms, which can vary depending on the plant genus.
Symptoms N P K Ca S Mg Fe Mn B Mo Zn With Overfertilization Upper leaves yellow X X Middle leaves yellow X Lower leaves yellow X X X X Red stems X X X Necrosis X X X X X Points X Shoots die X White leaf tips X X Crumpled Wheatgrass X X X Rolled yellow leaf tips X Twisted growth X
Damage caused by soluble salts Cause: Soluble salt damage can be caused by over-fertilization, poor water quality, accumulation of salts in aggregate media over time, and/or inadequate leaching. Fertilizers are salts, and in hydroponic systems they are the most common fertilizer. As water evaporates, soluble salts can build up in aggregate media if they are not adequately leached. Irrigation water can also have high levels of soluble salts, contributing to the problem.
The symptoms: Chemically induced drought can occur when the content of soluble salts in the planting substrates is too high. The result is that the plants wilt despite sufficient watering. Other symptoms include dark green foliage, dead and burned leaf edges and root death.
Detection: Soluble salt levels can be monitored/measured by tracking the electrical conductivity (EC) of irrigation water, nutrient solutions and leachate (a nutrient solution drained from the plant container).Correction: Soluble salts can be leached out with plain water. First, determine the cause of the high soluble salts level and correct it.
Boron Bo The cause: deficit in the fertilizer mixture.The symptoms: Insufficient flower formation, the flowers are smaller and deformed. Boron deficiency affects the apical meristems (growth points). Sometimes the meristem dies completely and the side shoots start to grow (broom effect). The meristems have shorter internodes, which are often thicker and show small and deformed leaves at the tip. The shorter internodes sometimes lead to dwarfism. The stems often have breaks and cracks. The fruits are sometimes deformed and corked. Cracks or spots are also possible. Older leaves can show necrosis.Detection: leaf analysis.Correction : Fertilizers containing boron: Borax or boric acid, but note that boric acid is highly toxic. Alternatively: If there is a general nutrient deficiency, complete fertilizers that also contain boron can be used.Boron toxicity Bo The cause: Boron toxicity is caused by too much boron applied to plants. Of the nutrients commonly applied as fertilizers, boron has the narrowest margin between deficiency and toxicity. It is easy to apply too much boron. Check the calculations of fertilizers before applying them and check again. It can also be found in irrigation water. It is important to check the boron level in a water source before use and to take into account the boron in the water when adding boron fertilizer.The symptoms: Symptoms of boron toxicity are yellow and dead spots on the leaf edges. Reduced root growth can also occur.Detection: Monitor the media and perform plant analysis.Correction : Determine the source of the excess boron and correct it.Calcium deficiency Ca The cause: Strong temperature changes can interrupt and hinder calcium uptake. Lack of light, cold and/or too humid environmental conditions. Fertilizer level too low. Calcium deficiency can be caused by under-fertilization, a nutrient imbalance or a pH value that is too low. It is also related to moisture management, high temperatures and low air circulation. Calcium is a mobile nutrient and is transported through the plant in the water-bearing tissues. Fruits and leaves compete for water. Low relative humidity and high temperatures can lead to an increased transpiration rate and increased transport to the leaves. In this case, a calcium deficiency can develop in the fruits.
The symptoms: The apical meristems (these are the dividing tissues of the plant) are deformed and die off without any noticeable symptoms on the oldest leaves. The upper part of the stem and flower bud may bend. Small and deformed leaves on the upper side. Unusually dark green leaves. Premature flower and fruit drop. After a deficiency, the leaves that were developing at the time of the deficiency often show a typical deformation/drying out or a white edge. This is called tip burn and is particularly common in lettuce and strawberries. Browning of the inside of a stem/head, around the growing point like in celery (black heart). Typical symptoms are also blossom end rot on peppers and tomatoes. Symptoms usually first appear as brown leaf edges on new plants or on the underside of the fruit. Blossom end rot in tomatoes and peppers. As symptoms progress, you may see brown, dead spots on the leaves. A lack of sufficient calcium can lead to rot.
Detection: Leaf analysis. Fruits have a poorer shelf life.
Correction : Make sure the pH is between 5.5 and 6.5. Add calcium nitrate or calcium chloride depending on whether you need the extra nitrogen or not.
In the greenhouse: Increase the temperature. More light. Without wind, the plant's nutrient transport is reduced - ensure air movement in the greenhouse.
Ferrum deficiency Fe The cause: The most common cause of iron deficiency is high pH in the media and/or irrigation water. It can also be caused by nutrient imbalance.The symptoms: Iron deficiency in plants shows itself as yellowing between the leaf veins. Note that this symptom appears first on new growth.Detection: Monitor the media and perform plant analysis.Correction : Correct the pH of the nutrient solution. If necessary, add iron fertilizer.Sulphur deficiency S The cause: Too little or incorrectly proportioned fertilizer. A pH value that is too low also blocks the absorption of sulfur. At a pH value of 4.0, sulfur absorption stops completely. Too little magnesium.
The symptoms: Extensive yellowing of the leaf tissue and the leaf veins. Often the younger parts of the plant first and later the whole plant. Symptoms are more likely to appear in young or freshly growing leaves at the top of the plant. Sulfur is an immobile nutrient. This means that sulfur can only be re-disposed (transported) relatively slowly by the plant. Lime green to yellow discoloration on leaves is characteristic of sulfur deficiency. It starts at the leaf stalk and moves to the leaf edges and tip. As the disease progresses, the entire leaves first turn yellow, then later brown and necrotic and then die completely. Sometimes purple/reddish leaf stalks on the affected leaves or even a purple stem. The symptoms of a mild deficiency are usually limited to the top of the plant. The middle part of the plant is hardly affected, lower leaves almost never.
Detection: leaf analysis.
Correction : increase the fertilizer dose. Correct the pH: keep it well above 4.0. 5.5 to 6.5 is a good average for many plants. Enrich the soil with Epsom salt / magnesium sulfate / MgSO 4 : one teaspoon per 2 liters of water (approx. 1% concentration).
Nitrogen deficiency N
The cause: Nitrogen deficiency can be caused by under-fertilization, nutrient imbalance or excessive leaching.The symptoms: Typical first symptoms of nitrogen deficiency are light green foliage and a general stunting of the plants. Wilting and dead and/or yellow leaf edges can also be observed. Yellowing of the entire leaf, including the leaf veins, can be seen. The older leaves turn yellow first, but the nitrogen deficiency quickly leads to a general yellowing. Necrosis or deformation of leaves or stems does not appear in the initial stage.
General growth retardation.Detection: Measuring/monitoring the electrical conductivity (EC) of nutrient solutions can help prevent nitrogen deficiency. Adjust the EC value if it is too low or too high.
Correction : Determine the cause and correct it. This may mean adding more nitrogen to the nutrient solutions. It may also mean there is too much of an antagonistic nutrient in the nutrient solution.The cause: incorrectly dosed nutrient solution. Plant consumption higher than calculated: a potassium deficiency often occurs in crops that bear a large amount of fruit.The symptoms: Wilting of the plants even at moderate temperatures. Leaf edge necrosis on the oldest leaves. Browning and curling of the lower leaf tips and yellowing (chlorosis) between the leaf veins. Purple spots may appear on the underside of the leaves. Yellowing: Yellowing also begins on the edges of the oldest leaves and develops towards the middle of the leaf. In some cases the leaf edge is not affected and the necrosis begins inside the leaf between the leaf veins.
Detection: Nutrient analysis and/or perform plant analysis.Correction : Re-dose. Check antagonist concentration: nitrogen, calcium, magnesiumNote: Too much potassium can cause severe stunting, redness, and poor germination. Excessive amounts of potassium can also make it difficult to absorb other ions such as calcium.The cause: incorrect fertilizer composition.The symptoms: White discoloration in the tips of the younger leaves. The leaves curl up in a corkscrew shape. Later they may die (necrosis).
The youngest leaves have difficulty unfolding. The youngest leaves curl up and wilt. Necrosis at the youngest growing points and the leaf margins of the youngest leaves.Correction : Add special copper fertilizer.Magnesia deficiency Mg Cause: Magnesium can be caused by a high pH of the medium and/or a nutrient imbalance between potassium, calcium and nitrogen.
The symptoms: Yellowing of the leaf tissue. The leaf veins remain green. This yellowing begins on the oldest leaves. Look for yellowing between the leaf veins as a symptom of magnesium deficiency: chlorosis or yellowing. Magnesium deficiency usually shows up first on the lower to middle leaves, which makes it easier to distinguish from iron deficiency. Premature leaf drop of the affected leaves. Sometimes the discoloration can be more brownish than yellow.Detection: Nutrient analysis and perform plant analysis.Correction : Correct the pH of the nutrient solution. If necessary, add magnesium fertilizer. Check the dosage of competing cation suppliers (K, Ca and N).Manganese deficiency Mn Cause: Too little or no fertilizer. Manganese deficiency is somewhat similar to iron deficiency: chlorosis between the leaf veins. Light green net on the leaves. It can also be confused with magnesium deficiency. With a manganese deficiency, the leaf veins (including the smaller veins) remain green, but the green stripes remain very narrow.
With a magnesium deficiency, these green stripes around the veins are wider and the finest leaf veins also turn yellow.The symptoms: Distinct network of green veins. Sometimes occurs on young, but already fully developed leaves (middle leaves).Correction : Add special manganese fertilizer. Increase fertilizer dosage.Molybdenum deficiency Mo The cause: Too little or no fertilizer. Many symptoms of a molybdenum and nitrogen deficiency are similar. The plant cannot use and process nitrogen without molybdenum.The symptoms: The plants are smaller and show a pale green color. The discoloration can develop into yellowing first on the edges and then between the main veins. The leaf disk disappears almost completely, only the main vein of the leaf remains with small pieces of leaf. This main vein is usually also wavy. (whipstick symptoms). The leaves remain smaller and sometimes take on a spoon-like shape: wavy edge and curved main vein.Correction : Add special molybdenum fertilizer.Phosphorus deficiency P The cause: The pH value may not be in the optimal range of 5.5 to 6.5. There may also be an imbalance of nutrients. Check the antagonist zinc dosage. In cold periods, a build-up of sugar in the leaves can show the same symptoms as a phosphorus deficiency.The symptoms: stunted and spindle-shaped growth, reduced leaf size and reduced number of leaves. Dull grey-green leaves with red pigments in the leaves. The phosphorus deficiency is mainly evident in the characteristic reddish to purple leaf discolouration, first on older leaves, and often the leaf veins are also affected.General growth retardation. Poor root development. Smaller plants than usual.
Detection: pH control and dosage monitoring. Nutrient analysis.Correction : Correct the pH value of the nutrient solution. If necessary, reduce the zinc content in the nutrient solution.Note: An excess of phosphorus can result in a deficiency of trace elements such as Zn, Fe or Co.Zinc deficiency Zn The cause: Possibly too high a phosphorus content in the nutrient solution or too little zinc in the nutrient solution.Symptoms: The following symptoms may occur: Chlorosis: yellowing of the leaves. Depending on the species, young leaves may be the most affected, while in others both old and new leaves are chlorotic. Necrotic spots: partial or total death of leaf tissue in areas of chlorosis. Leaf bronzing: chlorotic areas may turn bronze. Retarded plant growth: this may occur as a result of a decrease in growth rate or a decrease in the internode (the length of the shoot between two nodes). Dwarf leaves: small leaves that often show chlorosis, necrotic spots or bronzing. Malformed leaves: leaves are often narrower or have wavy edges.Detection: Monitor media and/or perform plant analysis.Correction : Correct the pH value and/or the amount of phosphorus if you know that there is enough zinc in the nutrient solution. Otherwise, add zinc in small doses. Remember: copper and phosphate reduce the absorption of zinc!ID: 418
