Rules for applying nitrogen-phosphorus-potassium fertilizers in autumn, spring and summer

Novice gardeners often do not understand why constant plant feeding is needed and why nitrogen fertilizers are needed at one stage of the growing season, and phosphorus-potassium fertilizers at the other. The fact is that the NPK triad (nitrogen, phosphorus, potassium) is the basis of nutrition for most plant organisms.

Why are nitrogen-phosphorus-potash fertilizers so important?

Plants, in order to live, must receive the necessary nutritional components. It:

• energy that comes with sunlight and heat;
• moisture from the air and soil;
• carbon dioxide, carbon in which is the building material of living tissues on the planet;
• oxygen;
• microelements, each of which solves its own problem;
• finally, the triad "nitrogen, phosphorus, potassium", which occupies a special place in plant nutrition. Nowadays calcium, iron, magnesium, sulfur are sometimes added to this.

Plants use about 70 elements, the lack of each of which can affect the functions. Hence the need for fertilizers - man-made sets of organic and mineral components for plant nutrition and soil fertilization. This is equally necessary for flowers, and for tomatoes, and for the lawn.

Nitrogen nutrition

The tissues of a living organism include protein molecules, in which more than 15% is nitrogen. In plants, it is the building block for chlorophyll, which is responsible for photosynthesis.

Lack of nitrogen nutrition is easy to notice by how the leaves are suppressed:

1. in the upper part of the plant - they become smaller;
2. in the lower part - curl up, and then begin to fall off;
3. everywhere change color to a paler one with yellowness.

In the planet's atmosphere, ¾ is nitrogen, but few of the organisms know how to extract it. There is also a lot of the element in the composition of the soil, but only 1-3% are forms that the plant can assimilate. Therefore, nitrogen fertilization is important.

Phosphorus nutrition

Phosphorus is one of the elements of the cell nucleus, and its role for plants is also great:

• forms nucleic acids, adenosine phosphates;
• determines the synthesis of carbohydrates, proteins;
• participates in the formation of enzymes, vitamins;
• with its help, energy exchange, inheritance is carried out;
• maintains the acidity of cell juice, intracellular pressure;
• responsible for the growth of roots - as a result, for productivity;
• important for the formation of flowers;
• increases resistance to adverse weather.

It is the second most important element of living nature after nitrogen.

Lack of phosphorus also affects the leaves:

• they become bluish in color;
• in the lower part of the plant are covered with dark spots;
• fold up, then begin to fall off;
• the petioles become reddish.

Phosphorus in the soil is represented, in contrast to nitrogen, in stable forms. But it is inaccessible to plants, which makes the application of phosphorus fertilizers vital for the harvest.

Potassium food

This is the third essential element for plants. It behaves in a special way, not associating with any compound. The ionic form of potassium enters the plant and remains so, being distributed throughout the cells.

More potassium where exchange is more intense. So for young plants the content of this element is 3-5 times higher than for adults.

Potassium-supported functions include:

• photosynthesis, plant respiration;
• moving carbohydrates from the leaves to other organs;
• protein synthesis;
• synthesis of sugars (for example, with a lack of potassium, tomatoes will be tasteless);
• increased intracellular pressure with resistance to cold;
• transformation of protoplasm cells with resistance to drought.

With a lack of potassium, the quality of products decreases, the possibility of plant reproduction.

Signs of a lack of potassium nutrition on the leaves:

• in the upper part of the plant - they become smaller and darker;
• in the lower part - they acquire light spots against a background of a faded color;
• a rusty tint appears at the edges;
• stepchildren are activated with a simultaneous thinning of the stems.

There is even more potassium in the soil than nitrogen and phosphorus, but only 1% is available (no more than 20 mg per 1 kg of soil). Therefore, potash fertilizer is relevant.

Often feeding is carried out as phosphorus-potassium, which is possible due to the compatibility of nutrients, as well as the coincidence of the timing of their introduction.

The composition of nitrogen, phosphorus and potash mineral fertilizers, which should be chosen

The industry currently produces a variety of NPK-containing fertilizers, both collectively and separately. What to choose?

Nitrogen fertilizers

Plants can assimilate 4 types of nitrogen derivatives:

• nitric acid salts;
• aqueous ammonia, its salts;
• urea (other names - carbonic acid diamide or urea);
• some amino acids.

Amino acids are not fertilized. And the rest is being implemented. But ammonia solutions are not allowed to be used in personal subsidiary plots because of the high danger.

If we choose according to the nitrogen content, then among the available fertilizers the leader is urea (46%). In second place is ammonium nitrate (34%). There is nothing "superfluous" here: nitrogen, oxygen, hydrogen and additional carbon in the carbamide.

Phosphate fertilizers

Phosphate fertilizers are divided into 3 groups:

• water soluble;
• soluble in weak acids, which allows them to be absorbed;
• insoluble and not immediately assimilated by plants - only after transformation by the soil medium.

The third group is the stock. And for the provision of ambulance, it is advisable to use the first group.

The leader in phosphorus content is double superphosphate (another name is calcium dihydrogen phosphate). Phosphorus in it is about 20%. Moreover, the calcium contained here in addition to phosphorus, oxygen, hydrogen can also be useful for planting. It is only necessary to take into account its application when using other calcium-containing fertilizers.

Potash fertilizers

If there is a need to use fertilizers, then potassium chloride is usually applied. It is the leader in potassium content. Its production is 90% of potash fertilizers. However, the composition contains a harmful chloride ion, which, for example, impairs the taste of tomatoes. Therefore, it makes sense to turn to sulphate, which occupies the 2nd place in potassium content, the sulfur-containing ion of which can be useful for plants. Another option is to use a mixture of potassium and magnesium sulfates, potassium magnesia with another useful element - magnesium.

Manure and the like

Manure, peat, other residues of plant and animal origin - complex fertilizer, as evidenced by the data in the table:

Fertilizer	N,%	Р 2 О 5,%	K 2 O,%
Peat	0,8-3,3	0,1-0,5	0,1-0,2
Bird droppings	0,5-2,2	0.1	–
Dry cow dung	2	1.8	2.2
Fresh cow dung on straw	0,4-0,8	0,2-0,6	0,5-0,9
Rotten horse manure	0,5-0,7	0.3	0.6
Fresh horse manure on straw	0.4	0.2	0.4
Overripe leaf litter	0.6	0.2	0.4

However, nitrogen from organic matter becomes available to plants only after mineralization. The scheme is multi-stage and depends on environmental conditions that are most favorable in spring, but not in autumn. This must be taken into account when applying organic fertilizers.

Ash

Wood ash is a valuable potassium-phosphorus fertilizer fortified with calcium. Hardwoods provide a higher content of nutrients. But also in the ash of coniferous species of potassium, phosphorus and calcium oxides 3–7%, 2–3% and 25–30%, respectively. Young plants give a richer composition.

Types of fertilizers and their application rates in autumn, spring and summer

In order for NPK fertilizers to play an important role in the formation of the crop, they must be applied according to the rules:

• annually;
• taking into account the rates of fertilization;
• in compliance with the deadlines.

For example, nitrogen fertilizers, so necessary for growth in spring, in the second half of summer and in autumn, are only harmful, since they stimulate the formation of young growth. Annuals do not need this, but for perennials it creates a threat of freezing. But phosphorus and potassium, which increase resistance to adverse conditions, will, on the contrary, be very useful in the fall, but only until the active vegetation of plants is over.

Fertilizers for tomatoes

To improve the growth and taste of tomatoes, they must be systematically looked after using fertilizers:

• in the fall for digging - 50 g of potassium salt per 1 m² (even chloride is suitable);
• in spring by 1 m² add a bucket of compost or humus, 0.5 liters of ash, 1 teaspoon of carbamide;
• further, only liquid forms are suitable.

For tomato seedlings with 2-3 leaves, root dressings are started every 10-14 days (the plants must be pre-watered):

• Take 1 l of water, dissolve 0.5 g of ammonium nitrate, as well as 2 g of potassium sulfate and double superphosphate.
• Another option is to infuse 1 heaped teaspoon of ash in 1 liter of water.

If the color of the leaves acquires a purple tone, it is necessary to make foliar feeding, pouring 1 g of double superphosphate with 0.1 l of hot water and keeping it for a day. Before use, the solution is filtered, diluted to 1 liter.

Fertilization is required not only at the stage of growing seedlings:

1. When planting tomatoes in a permanent place at the beginning of summer, 0.5 liters of rotted organic fertilizer and 1 tablespoon of ash are added to each hole.
2. After 2 weeks, root top dressing is started at the rate of 1 liter per plant - for example, taking 20 g of nitrogen and potassium fertilizer per 10 liters of water, as well as 50 g of phosphorus fertilizer.
3. A good effect is given by foliar dressing - spraying with an infusion of 0.5 liters of ash in 10 liters of water.
4. With the beginning of flowering, nitrogen fertilization stops, and the application of phosphorus-potassium fertilizers must be continued to support the formation and ripening of the crop.

Fertilizers for flowers and lawns

Fertilization in the fall and spring before planting or to prepare for the winter of previously planted ornamental crops (flowers or lawn grass) can be the same as when caring for tomatoes:

• In the fall, these are phosphorus-potassium fertilizers or ash.
• In the spring, urea is added or liquid complex preparations with a set of macro- and microelements are used.

In spring or early summer, you can very effectively fertilize perennial flowers with the help of special sticks or long-acting tablets, which gradually give the plants nutrients. And during the summer, foliar dressing is applicable, which is sometimes not given enough attention when caring for flowers and even more so for a lawn.

People eat every day without forgetting about it. So are the plants. You can help them by using a variety of fertilization options to enjoy the beauty and harvests later.