Mineral Fertilizers
The largest number of fertilizer names we will meet among mineral fertilizers.
Their main advantage is in chemical "specialization"( as a rule, they contain one of the nutritional elements).The main drawback, paradoxically, is the same.
What is the plus of mineral fertilizers? The fact that in different periods of growth and development of plants, their need for nutrients is not the same.
During the growth period, plants need most of all nitrogen. During flowering and fruiting - in phosphorus and potassium( especially the latter is needed at the end of vegetation, that is, the period of active vital activity, after all, even many indoor plants in winter go into a state of rest).Mineral fertilizers can give the plant exactly what it needs, and then when it needs it.
Minus of mineral fertilizers - in that they alone can not do without. Remember: the plant needs eight macronutrients. And mineral fertilizers are "confined" to only three of them. They were invented and created based on agricultural land, and any field is an open system, and some substances consumed by crops( for example, magnesium or sulfur) in it safely continue to flow from neighboring land. This luxury is not available to the house plant, natural resources are separated from it by the walls of the pot( and the walls of the apartment).And the former belief in the self-sufficiency of the "magic" combination of NPK( ie nitrogen-phosphorus-potassium) remained unshakable only among agronomists of the old school, while the industrial production of fertilizers continues to revolve around this "trinity".
There is another important( but rarely mentioned) circumstance: the use of mineral fertilizers can affect other soil properties, for example, on acidity, the degree of salinity, etc., which requires an especially cautious and careful approach to their use.
According to the predominance of this or that element( "active substance"), mineral fertilizers are divided into nitrogen, phosphorus, potassium and complex fertilizers.
Often in the reference literature, descriptions of the appearance of mineral fertilizers are given. The author considers this unnecessary: packages with fertilizer, as a rule, are signed. And if you do not know exactly what substance you are dealing with, it's better to refrain from using it.
There are 2 ways of applying mineral fertilizers: the main fertilizer( before planting) and top dressing( during the growing season).They can be used both in solid form( when applied directly to the soil), and in the form of a solution.
Solutions should be used immediately for cooking.
Do not try to apply dissolved mineral fertilizers more than once every ten days!
Nitric fertilizers
Nitrogen fertilizers include: ammonium nitrate( also ammonium nitrate or ammonium nitrate), ammonium sulfate( ammonium sulphate), sodium nitrate( sodium nitrate or sodium nitrate), urea, calcium nitrate- calcium nitrate, or calcium nitrate), montane saltpeter( it is the same as leucine saltpeter, or ammonium sulfonitrite), calcium cyanamide, ammonium chloride, etc. In short, everything where the words "saltpetre", "ammonium", or partsthe words "amide" or "nitro"( the chemical name "nitrogen" - "itrogenium ") relates specifically to the nutrients.
Warning! A typical feature of mineral fertilizers: they are usually chemically far from neutral( in this case, urea is a happy exception), and the supply of nutrient elements to the plant is not limited to their effects, and the "side effects" of each of the nitrogen fertilizers are best written out or memorized separately.
Ammonium nitrate, ammonium sulfate, montane saltpeter and ammonium chloride acidify the soil. Ammonium chloride also salts it with chlorine, and some plants do not tolerate chlorine at all.
Sodium nitrate, calcium nitrate and calcium cyanamide are alkalinized. In addition, calcium cyanamide in the first stage of its transformation in the soil forms quite poisonous compounds( it is no coincidence that its name echoes the name of cyanic acid), so it is not suitable for fertilizing at all: it has been introduced into the soil since autumn.
So, before making a nitrogen fertilizer, make two corrections for:
1) what is the acidity of the original soil;
2) which environment the plant prefers.
Only in this way you will be able to choose not only the necessary, but also safe for use fertilizer. If, for some reason, the choice of fertilizers is limited, and the available substances can change the acidity in the undesirable direction, take care to neutralize them.
Attention! Do not trust rumors that a mineral fertilizer should use liquid ammonia( a solution of ammonia in water, which can be found in the pharmacy).Although there is a lot of nitrogen in it, ammonia vapors cause severe burns in the plant, if this substance is at a depth of less than 10-12 cm. In agriculture, special machines are used for its application to the soil. On a garden plot( and especially at home) it should not be used at all.
Norms for the application of nitrogen fertilizers
Ammonium nitrate, urea and moptan-saltpetre: in dry form - from 10 to 25 grams, in solution - from 4 to 8 g per 1 m2.Potassium cyanamide, ammonium chloride( because of the relatively small amount of active ingredient, the dose might be greater, but to avoid side effects it is reduced): 20-30 g in dry form per 1 m2.Ammonium sulphate - 30-50 g in dry form per 1 m2.Sodium and calcium nitrate: up to 70 g per 1 m2.
Nitrogen fertilizers( except cyanamide) should be added in the spring, because at this time of year, the plants are most often threatened by nitrogen starvation. They are used as basic, not feed.
Phosphoric fertilizers
Traditional phosphoric fertilizers are simple and double superphosphate, precipitate, tomaslag, thermophosphate, phosphorite and bone flour( the latter is still considered as a simple organic fertilizer, given the origin, it is more logical to consider it as a simple organic fertilizer, see above).
Phosphate fertilizers can be used both as basic and for top dressing. The spread of their chemical properties is much less than that of nitrogen fertilizers.
Simple and double superphosphate differ in the degree of concentration, and therefore, the application rates in the soil: simple - for the main fertilizer 30-50 g, for feeding - 15-25 g per 1 m2, double - for the main 14-28 g, for top dressing10 g per 1 m2.Both are best used in a mixture with humus because of the propensity to form compounds that are hard to reach from the interaction with the soil. Particularly effective is the granular form.
Precipitates are close in action to superphosphate, used primarily as the main fertilizer. The norm is the average between simple and double superphosphate.
The peculiarity of the tomslag and thermophosphates is that, unlike the previous ones, they can not be mixed with ammonia fertilizers. There is a slight difference between these two substances in the concentration of phosphorus. The norms for both are similar to those of simple superphosphate.
Phosphorite flour contains few readily available forms of phosphorus, therefore it is used as the main fertilizer( more often - in autumn) in high doses - up to 80 g per m2.This fertilizer may last for several years. For indoor plants the use of phosphate flour is not very convenient, since the volume of soil in the tank is small. An important point: the higher the acidity of the soil, the better absorbed phosphoric flour. For the same reason, it combines well with acidic nitrogen and potassium fertilizers.
Potash fertilizers
Potassium chloride, 30-40% potassium salts, sylvinite, cainite, potassium sulfate, potassium magnesium sulphate( kalamashezia) and carnallite are among the most important potassium fertilizers, with sylvinite( natural mineral) being the starting material forproduction of most of the rest, in many respects, and determines the commonality of their properties. Cainite and carnallite are independent natural minerals that contain, in addition to potassium, magnesium necessary for plants. Magnesium is also present in calimagnesia.
All potash fertilizers can be used on any soil and are readily soluble in water. The disadvantage of many is the presence of chlorine, so it is better to use potassium sulfate on saline soils and for chlorine sensitive crops. Cainite and carnallite require more moisture.
Application rates. Potassium chloride: for the main fertilizer 20-40 g, with top dressing 3-5 g;potassium sulphate: for the main fertilizer 10-15 g, for feeding - 2-4 g;potassium salts: 30-40 g;calimagnesium - 25-35 g;other potash fertilizers - 40-60 g per 1 m2.
Lime fertilizer
This is a special category of fertilizers, as they serve simultaneously as ameliorants of acidic soils, which sometimes leads to confusion: both of their roles are important enough. Their nutritional element is calcium.
The most well-known and widespread limy fertilizers: calcareous tuff, ground limestone, hydrated lime, chalk, dolomite flour, marl, cement dust and peat ash.
The meliorative alkalizing effect of calcareous fertilizers is so strong that for soil with pH above 5.5 it is better not to use them at all, especially strong ones( slaked lime, ground chalk, dolomite flour, cement dust).Tea bush, for example, this fertilizer generally will not be to taste.
Due to the fact that the dosage is highly dependent on the acidity of the soil and its mechanical composition( for sandy and loamy soils of lime fertilizers it is required to be one and a half to two times less!), It is difficult to bring specific standards.
Complex fertilizers
Complex are called those mineral fertilizers that contain two or three NPK elements. These include ammophos, nitrophos, nitroammophoska, potassium nitrate and wood ash.
Ammophos( just ammophos and diammophos) are ammonia salts of phosphoric acid, that is double fertilizers. Ammophoses readily dissolve. The disadvantage of this complex fertilizer is that it has relatively little nitrogen. In addition, ammophoses slightly acidify the soil.
Nitrofosca and nitroammophoska are triple fertilizers. Nitrofos contains relatively little phosphorus, the rate of its application is 45-60 g per m2.Nitroammophoski is required somewhat less - 40-50 g. They are introduced in the spring as the main fertilizer and in the summer as a fertilizing.
Potassium nitrate is a double concentrated fertilizer. The rate of application is 12 -18 g per m2.
Wood ash is a fertilizer that is not even triple, it contains almost all the necessary elements, but. .. it needs a lot more: from a quarter to a half a kilogram per m2 because of not too good availability of nutrients. Sometimes wood ash is also considered as a calcareous fertilizer.
For cultivation of plants in rooms there appeared specialized complex mineral fertilizers. Often they also contain trace elements.
Warning! If you do not have weights at the dacha, they can be replaced by a matchbox of standard volume( 20 cm3).It is available in grams:
• ammonium nitrate - 17 g
• potassium nitrate - 25 g
• calcium nitrate - 18 g
• sodium nitrate - 22 g
• urea - 15 g
• ammonium sulfate 17 g
•superphosphate - 22 g( granular) or 24 g( powdery)
• phosphorite flour 34 g
• potassium chloride 18 g
• caligagnesia - 20 g
• wood ash - South
• lime - 12 g