Potato fertilizers: types, application methods, application schedule

Fertilizers and preparations

Potato fertilizers play a crucial role in their cultivation. Depleted soils deficient in micronutrients will not yield a bountiful harvest of tasty, crisp potatoes. There are many methods for using different types of fertilizers. The timing of application, quantity, and composition determine the agricultural practices for potato plantations. In home gardens or agricultural complexes, complex mineral fertilizers and organic fertilizers are used. In small vegetable gardens and orchards, herbal infusions and decoctions are used to fertilize plants.

Useful properties of fertilizers

Potatoes obtain most of their nutrients from the soil. It must contain the necessary substances for normal growth and development. If the soil lacks a particular element, potatoes often become diseased and are attacked by pests. Fertilizers help restore the nutrient content of the soil. To apply fertilizers that specifically contain the component deficient in potato nutrition, it's necessary to determine the soil's chemical composition.

In heavy clay soils, potato tubers are often small, and moisture and air are difficult to reach. Organic matter such as manure, bird droppings, compost, or granulated organic garden fertilizers improve the soil structure and enrich it with nitrogen and micronutrients. In loose, nutrient-rich soil, the plant's tubers receive sufficient moisture and air. The production of large, healthy potatoes increases exponentially.

A deficiency or excess of essential nutrients—nitrogen, potassium, phosphorus, or calcium—can cause potato diseases. Symptoms include yellowing of the tops and the appearance of new growths on the roots. Timely application of organic and mineral fertilizers helps protect plants from further disease development.

The best fertilizers for potatoes

Chemical or organic products should be applied at specific times and dosages, as specified by the manufacturers in the instructions for use. When growing potatoes, it's important to know the soil composition in the area intended for planting. It's crucial to study its characteristics. This way, vegetable growers will know exactly which elements are deficient in the soil, and which ones pose a risk of disease and death to the potatoes.

Types and varieties

There are two main types of fertilizers:

Mineral fertilizers are inorganic (chemical) compounds containing salts of various minerals. They are essential for normal plant growth and development. These fertilizers vary in composition: nitrogen, phosphorus, potassium, or complex additives. Their characteristics and effects on plants also vary: complete, extended-release, universal, and complex formulations. They are available in powder, granular, or liquid form.
Organic fertilizers for garden beds are made up of naturally occurring ingredients: manure, peat, compost, and green manure. Their main advantages include increased nitrogen content, improved ecology and microflora in potato plots, improved soil structure, and a supply of naturally occurring micronutrients to plants.

Attention!

When applying fertilizer, avoid using fresh manure. It contains highly concentrated chemicals. These have a negative impact on the plant, causing root burns and spotting on leaves and stems.

Mineral fertilizers: their types and characteristics

Table 1

Group	Name	Compound	Properties
Nitrogen	Urea, ammonia water, potassium, sodium nitrate, nitrate fertilizers	16-45% nitrogen	They enrich the soil with nitrogen and stimulate the growth of potato roots and tops.
Phosphorus	Bone meal, simple and double superphosphate	18-26% phosphorus oxide	They replenish phosphorus reserves in the soil and protect potatoes from diseases.
Potassium	Potassium salt, potassium chloride and potassium sulfate, potassium sulfate, potassium nitrate	30-60% potassium oxide	They increase the potassium content in the substrate, normalize plant photosynthesis, and control water balance.
Complex	Nitrophoska, nitroammophoska	Nitrogen + potassium + phosphorus (in different percentages)	They have universal properties (see above)
Microfertilizers	Micromineralis, Fusco, Helatin	Calcium, iron, manganese, magnesium, boron, selenium	They improve the soil microclimate, participate in potato photosynthesis, and promote plant health in the event of a lack of microelements.
Organomineral (complex) fertilizers	The group includes soft humic potassium fertilizers, liquid, granular or powder mixtures: OMU, Hera, Biohumus, Souffler, Humate	Manure (horse, cow) or bird droppings + mineral supplements (macro and microelements)	They enrich and improve the soil, breaking up compacted soil particles. They are quickly absorbed by plants and stimulate growth and tuber formation.

Organic fertilizers: their types and characteristics

Table 2

Names	Compound	Properties	Application
Manure (horse and cow)	Animal feces + rotting bedding made from straw, grass or sawdust	Improves the humus layer of the soil, increases potato yields	Only rotted material is added, extracts are prepared from fresh manure and 1 liter of solution is poured into the holes when planting potatoes.
Bird (chicken, duck, goose) droppings	Bird droppings + small particles of soil, stones, shells, rotten grass	Protects the plant from diseases, replenishes the lack of nitrogen and calcium	It is used in aqueous solutions and infusions at a concentration of 1:15.
Green manure (liquid fertilizer made from grass)	Mown grass, weeds, fallen leaves	Root feeding stimulates tuber growth. Foliar application protects potatoes from foliar and stem diseases.	Herbal infusions are used to feed potatoes. Herbal fertilizers are infused for at least 24 hours. They do not need to be diluted.

Attention!

It's best to apply manure no more than once every 3-5 years. Excess manure in the soil reduces potato yield.

Rules for using fertilizers for potatoes

Soil preparation for potato planting begins in the fall after the harvest. The plot is cleared of old tops and weeds, the soil is dug over, and the soil is disinfected against pests and pathogens. Pesticides are used for this purpose, and herbicides are used to control weeds.

Before winter, fertilizers should only be applied to heavy clay soils. This is done to improve the soil structure. Manure, peat, sand, sawdust, and slow-release humic fertilizers are used.

On lighter soils, this is ineffective, as most of the nutrients will be washed away by meltwater before spring. The main work associated with fertilizing a potato plot is carried out in early spring after the ground has cleared of snow.

How to fertilize potato soil in spring

In April, spread organic matter around the plot: rotted manure and peat (once every 3-5 years). If this fertilizer is insufficient, you can add 100 g to each hole. Add a layer of soil on top to prevent the tubers from coming into contact with the manure. Then, scatter dry complex mineral fertilizers over the plot (30-50 g per 1 m²).

The second method of application is directly into the hole. It's important to remember that organic matter and chemicals should not mix in the soil, otherwise an immediate chemical reaction will occur and essential plant nutrients will evaporate.

After pre-sowing fertilization, potatoes are fed 2-3 times during the season. Infusions and extracts of manure, mown grass, and mineral salt solutions are used for this purpose.

Root and foliar feeding of potatoes

Feeding potatoes Fertilization should be done at least 3-4 times during the growing season. This is essential for a good harvest. Before planting, apply fertilizer to the roots to provide the plant with nutrients for 3-4 weeks. Subsequently, such fertilization should be repeated every 14-20 days, as potato sprouts and roots constantly absorb nutrients from the soil along with moisture.

Potato tops are treated 1-2 times as needed. The foliage and stems are sprayed with solutions of mineral or organic fertilizers at the first signs of disease, such as leaf spotting or curl. For this purpose, products containing the micronutrients the plant is lacking are used.

Signs of nutritional deficiencies

A deficiency or excess of nutrients in the soil is reflected in the foliage and stems of potatoes. These characteristic signs help determine which nutrients need to be added to the soil to alleviate these unwanted symptoms.

Lack of nutrients in the soil	Signs on potatoes
Nitrogen	The plant's leaves and stems are growing poorly, with white spots appearing on the undersides, which gradually expand and turn yellow. The foliage thins, and the number of leaves decreases, causing the starch content in the tubers to decrease.
Phosphorus	Potato tops fail to develop green mass, stems, and tubers fail to grow. Leaf blades become deformed and curl upward. Black spots appear on the tubers, and over time, the fruits wrinkle, darken, turn purple or red, and lose their flavor.
Potassium	The tubers become deformed, the leaves turn yellow at the edges, become small and wrinkled, and develop a bronze tint.
Magnesium	The leaves of the tops become smaller and turn pale green, which gradually turns into brown shades.
Calcium	Light stripes form on the foliage, and the plant tissue dies in these areas. The leaf blades wrinkle, and their edges curl upward.
Iron	The leaves of the tops begin to turn yellow and acquire a whitish color.
Bor	The potato tubers are small, cracked, and have black centers. The upper part of the plant turns white and dies. The center of the plant grows, the leaves become dense, but after turning brown, they quickly fall off.
Copper	The foliage withers and the leaves curl, but their color does not change.
Zinc	The petioles and stems of the leaves turn grey, their core dies, the leaves curl upward and fall off.
Manganese	Young green leaves at the top of the plant become covered with small brown spots, but the lower part of the tops does not change color.

The effect of fertilizers on soil

Fertilizers used when growing potatoes are quickly absorbed by plants. They don't accumulate in the soil in dangerous amounts, improving and enriching it with nutrients. Danger awaits gardeners when there's an excess of nitrogen compounds in the soil. In this case, the nitrate content in potato tubers increases, making them unfit for consumption.

Organic fertilizers (manure, ash, peat) improve the structure of the soil, making it lighter and looser.

Attention!

Applying too much fertilizer is just as dangerous as not applying enough. It's important to constantly monitor the condition of your potato plot. Apply fertilizer carefully, avoiding overdosing.

How to calculate the required fertilizers

Fertilizer application must adhere to specific rates. Average rates are developed by specialists, as not every gardener can calculate them accurately due to the complexity of the formulas.

Degree of soil fertility	Amount of required mineral fertilizers per 100 m2	Amount of organic matter
Fertile	2.5 kg of nitrogen-containing and 1.5 kg of potassium-containing,	2-2.5 kg
Average fertility	3 kg of nitrogen, 4 kg of phosphorus, 2.5 kg of potassium fertilizers	3-4 kg
Poor (depleted) soils	1 kg of saltpeter and 3 kg of superphosphate	About 100 kg

The total amount is calculated for a full season's worth of fertilizer application. The bulk (50%) is applied in the spring before planting potatoes. The remaining amount is divided into 2-3 portions and applied as top dressing over 2-3 applications.

General tips for working with fertilizers

Additional recommendations for applying mineral and organic fertilizers are needed by beginning gardeners:

Organic matter is added in the spring in the form of rotted manure. It is spread throughout the plot or added to the hole before planting. Aqueous solutions and extracts of manure and bird droppings are used for fertilizer.
Powdered and granulated mineral fertilizers are scattered over the potato plantation or placed locally in planting holes.
Do not allow the tubers to come into contact with fertilizers; it is necessary to make a small layer of soil.
Nitrogen fertilizers are used only until mid-summer, so as not to stimulate “fattening”, that is, the growth of green mass (tops).
When working with fertilizers, watering cans, sprayers, hoes, scoops, and pitchforks are used.
Some substances cannot be used simultaneously: potassium nitrate should not be mixed with manure and bird droppings, nitrophoska - with organic matter, ash, dolomite, superphosphate - with urea and chalk.
It is not recommended to apply fertilizers deep into the soil (more than 30 cm). This reduces the effectiveness of the minerals on the plant.
Avoid applying large amounts of fertilizer until the ground is clear of snow. During this time, many microorganisms die, providing no benefit.

To preserve the ecology of potato plantations, it's best to reduce the use of chemical fertilizers, but remember that excessive use of organic components can also be harmful. It's important to maintain balance and know when to stop.

Storage conditions

Long-term storage areas for mineral fertilizers (sheds, garages, cellars, and basements) must be well ventilated. Each type of chemical should be stored separately, in plastic, paper, or fabric bags and boxes. Liquid fertilizers should be stored in sealed plastic bottles.

Containers must be tightly sealed, and bottle caps must be tightly closed. Moisture must not penetrate into storage areas. Permeable bags and boxes should not be placed on the floor; under-shelf racks should be used for this purpose.