Nutrition

Structure of the Storage Root and What Determines Its Quality

The beetroot consists of three parts: the crown (shortened stem with buds), the neck (enlarged hypocotyl), and the true root (Balashev and Zeman, 1981; Torikov and Sychev, 2018). The neck and the upper part of the root make up the main edible mass.

On a cross‑section, alternating dark and light rings are visible. The dark rings are fleshy parenchyma rich in nutrients and sugars. The light rings are vascular‑fibrous bundles and cambial layers, which contain fewer nutrients and have a coarser texture (Autko et al., 2012). The more dark rings there are and the wider they are, the higher the root quality. Plant nutrition is what determines this ratio.

Role of Nutrients in Yield Formation

Each mineral nutrient performs a unique function in the life of beet:

Nitrogen (N) — the driver of growth. It stimulates protein and chlorophyll formation, leading to rapid leaf mass accumulation. However, excess nitrogen delays the transport of carbohydrates from leaves to the root, reduces sugar content, and impairs storage quality (Tarakanov and Mukhin, 2003; Roy et al., 2026).

Potassium (K) — the main quality element. It activates enzymes involved in sugar synthesis and transport. Potassium also increases plant resistance to drought and diseases and improves root storability (Gashash et al., 2022).

Phosphorus (P) — the basis of energy metabolism. It is a component of ATP, nucleic acids, and cell membranes. Phosphorus stimulates root system development, which is especially important in the early growth period of beet (Gashash et al., 2022; Nonnecke, 1989).

Boron (B) — a critically important micronutrient. It is responsible for carbohydrate transport from leaves to the root and for the integrity of cambial tissues. Boron deficiency causes dieback of the growing point and heart rot — one of the most common beet diseases (Rana, 2018; Balashev and Zeman, 1981).

Sodium (Na) — a specific element. Although beet is not a halophyte, it responds positively to sodium application, especially on light soils. Sodium promotes more efficient water use and can partially substitute for potassium in some physiological processes (Nonnecke, 1989; Tarakanov and Mukhin, 2003).

Why Balance Matters

Beet is particularly sensitive to nutrient imbalances. This is due to its botanical feature — a polycambial root type, where many concentric cambium rings simultaneously form storage tissue. Deficiency or excess of any element can disrupt this process.

For example, with excess nitrogen and insufficient potassium and phosphorus, top growth outpaces root development. Leaves become large and dark green, but the root remains small with low sugar content. Such roots store poorly. Conversely, nitrogen deficiency slows growth, leaves turn yellow, and roots become coarse and fibrous.

How to Assess Beet’s Nutrient Needs

The first and most reliable method is soil agrochemical analysis. Optimal values for table beet:

• Soil pH: 6.0–7.0 (beet suffers greatly on acidic soils)
• Humus content: at least 2.0%
• Available phosphorus: at least 150 mg/kg of soil
• Exchangeable potassium: at least 150 mg/kg of soil

The second method is visual diagnosis based on plant appearance. Beet is very responsive to nutrition, and its appearance can reveal much about element deficiencies.

Symptoms of nutrient deficiencies (Rana, 2018; Tarakanov and Mukhin, 2003):

The third method is considering the preceding crop. Beet grows well after crops that received organic manure: cucumber, zucchini, tomato, early potato, cabbage. Poor predecessors are other root crops (carrots, beets) and crops that heavily deplete the soil (Nonnecke, 1989; Torikov and Sychev, 2018).

Key Takeaways

1. Beet yield is determined by the balance between top growth and root development. The gardener’s task is to provide a nutrition regime where plants first build a strong leaf rosette and then channel carbohydrates into the root.

2. All nutrients are interconnected. Applying only one element cannot fix the situation — for example, nitrogen alone without potassium and phosphorus not only fails to increase yield but worsens quality.

3. Beet is especially demanding of boron and potassium. These are most often the limiting factors for yield and quality.

4. Root quality is as important as size. A root with high sugar content, vivid colour, and no voids is far more valuable than a merely large but coarse and watery one.

5. Soil analysis is the foundation of sound nutrition. Without it, any recommendations are approximate. You can have your soil tested at a local agrochemical laboratory — it will pay off in crop quality.

How Beet Uses Nitrogen

In the first growth period (from emergence to row closure), beet consumes nitrogen most intensively. At this time, the main assimilatory apparatus — leaves that will supply the root with carbohydrates — is formed. Nitrogen is a component of chlorophyll, so with sufficient nitrogen, leaves are bright green and photosynthesise actively (Tarakanov and Mukhin, 2003).

In the second half of the growing season, when the root begins to actively enlarge, the need for nitrogen decreases. At this point, potassium and phosphorus take the lead, ensuring carbohydrate transport from leaves to the root. If nitrogen fertilisation continues actively during this period, leaves keep growing while the root accumulates excessive nitrates and water. Sugar content drops, and storage ability worsens (Gashash et al., 2022; Roy et al., 2026).

Signs of Nitrogen Deficiency and Excess

Nitrogen deficiency appears first on older lower leaves: they become pale green, then yellow and die. Plant growth slows, and the root becomes small, coarse, and fibrous. This often occurs on poor sandy soils or after crops that have depleted nitrogen reserves.

Nitrogen excess is equally dangerous. Leaves become dark green, large, succulent but brittle. Foliage grows at the expense of the root. The root itself becomes watery, with low sugar content, stores poorly, and is prone to diseases during storage. Moreover, such roots accumulate nitrates, which is undesirable for product quality (Torikov and Sychev, 2018; Rana, 2018).

Forms of Nitrogen Fertilizers for Beet

Beet responds well to different nitrogen forms, but there are important nuances.

• Ammonium nitrate (34% N) — a universal fast‑acting fertiliser. Contains nitrate and ammonium nitrogen, providing both quick and prolonged effects. Good for spring application.

• Urea (46% N) — a high‑concentration fertiliser. Best applied before sowing or as liquid top‑dressing, as it hydrolyses rapidly in soil. However, on alkaline soils, nitrogen losses as ammonia may occur.

• Ammonium sulfate (21% N + 24% S) — a physiologically acidic fertiliser. Recommended on neutral and alkaline soils to acidify the medium. Contains sulfur, which is also beneficial for beet.

• Sodium nitrate (16% N + 26% Na) — the oldest fertiliser, especially effective on acidic soils. It does not acidify the soil and simultaneously supplies plants with sodium, which is useful for beet (see Chapter 5). Suitable for top‑dressing during growth (Nonnecke, 1989; Balashev and Zeman, 1981).

Optimal Rates and Timing

Nitrogen rates depend on soil fertility and target yield. Beet removes about 3–4 kg of nitrogen per tonne of roots and corresponding tops (Tarakanov and Mukhin, 2003; Autko et al., 2012). However, plants take up only part of the applied nitrogen, so recommended rates are higher.

Average approximate rates (for temperate climates):

• On soils of medium fertility: 80–120 kg N/ha (about 1–1.5 kg per 10 m²).
• On poor soils: up to 150 kg N/ha.
• On humus‑rich soils: 60–80 kg N/ha.

For home gardeners this means:

• At sowing — apply 1/3 of the total nitrogen together with phosphorus‑potassium fertilisers in rows or holes.
• First top‑dressing — 3–4 weeks after emergence, when plants have 3–4 true leaves. Apply the remaining nitrogen.
• Second top‑dressing — 20–25 days after the first, but no later than mid‑July (for the Northern Hemisphere). In this feeding, nitrogen is given at half dose, with emphasis on potassium and phosphorus.

Important rule: once the root reaches the size of a walnut, nitrogen rates should be reduced or eliminated altogether. All subsequent feedings should be potassium‑phosphorus. This ensures sugar accumulation and improves storability.

Practical Recommendations

1. Do not apply fresh manure directly under beet. Organic fertilisers are better applied to the preceding crop. Fresh manure contains much ammoniacal nitrogen, which can cause “luxuriant” top growth and lead to forked and misshapen roots (Nonnecke, 1989; Balashev and Zeman, 1981).

2. Use slow‑release nitrogen forms (e.g., urea‑formaldehyde fertilisers) for carrots and other root crops, but for beet they are less critical because of its strong root system. However, on light sandy soils, nitrogen should be split to avoid leaching (Tarakanov and Mukhin, 2003).

3. Combine nitrogen with potassium and phosphorus. Research shows maximum effect from combined N, P, and K application. One‑sided nitrogen fertilisation reduces root quality (Balashev and Zeman, 1981; Gashash et al., 2022).

4. Consider soil moisture. Nitrogen is well absorbed only with sufficient moisture. In dry weather, top‑dressing is ineffective; it should be combined with irrigation or done after rain.

5. Observe plants. If lower leaves start yellowing — a signal of nitrogen shortage. If leaves are dark green and large but the root is not growing — reduce nitrogen and increase potassium.

Key Takeaways

• Nitrogen is crucial for top growth, but excess reduces root quality.
• Best strategy: split application — 1/3 at sowing, 2/3 in 1–2 top‑dressings up to mid‑season.
• After root formation, shift emphasis to potassium and phosphorus.
• Apply organic matter in autumn to the preceding crop or at least one month before sowing.
• A sign of correct nitrogen management is moderately green leaves, firm roots with vivid colour and good sugar content.

In the next chapter, we will look at how potassium affects sugar content and storability and why this element is as important as nitrogen.

Why Beet Needs Potassium

Potassium is not part of organic molecules, but it activates over 50 enzymes involved in carbohydrate synthesis and transport. In beet, potassium performs several key functions:

1. Transport of sugars from leaves to the root. Potassium ensures the movement of photosynthates (sucrose) through the phloem. The more potassium available, the more efficiently carbohydrates flow from the tops to the storage tissue of the root. That is why with good potassium nutrition roots become sweeter (Gashash et al., 2022; Tarakanov and Mukhin, 2003).

2. Regulation of water balance. Potassium controls stomatal opening and closing, affects cell turgor, and drought tolerance. Beet supplied with potassium better withstands temporary moisture deficits and suffers less from temperature fluctuations (Nonnecke, 1989).

3. Increased disease resistance. Potassium strengthens cell walls, making tissues denser and less accessible to pathogens. Potassium fertilisers reduce the risk of storage rot and other diseases during storage (Autko et al., 2012).

4. Improved storability. Roots with high potassium content have a firmer structure, less tendency to wilt and sprout. They store better over winter, retaining market appearance and flavour (Rana, 2018; Balashev and Zeman, 1981).

Signs of Potassium Deficiency

Potassium deficiency appears first on older lower leaves, as potassium is easily moved from old organs to young ones. Typical symptoms:

• Marginal scorch — yellowing and dying of tissue along leaf edges, starting at tips.
• Leaves become brittle, wrinkled, and may curl downward.
• Plant growth slows, internodes shorten.
• The root is small, with low sugar content and poor storability.

Potassium deficiency is particularly common on light sandy and peaty soils, where potassium is easily leached, and on soils with high magnesium or calcium, which compete with potassium for root uptake (Nonnecke, 1989).

Forms of Potassium Fertilizers for Beet

When choosing a potassium fertiliser, consider its effect on soil and the content of accompanying elements.

• Potassium chloride (60–62% K₂O) — the most common and affordable fertiliser. However, chloride can negatively affect beet, especially at high rates. Therefore, potassium chloride is recommended for autumn application under ploughing, so that chloride is leached from the root zone before spring sowing (Torikov and Sychev, 2018; Balashev and Zeman, 1981).

• Potassium sulfate (50–52% K₂O + 18% S) — chloride‑free, therefore safe for beet at any time. Also contains sulfur, which improves protein synthesis and sugar content. This is the preferred form for top‑dressing during the growing season.

• Potassium magnesium sulfate (30% K₂O + 10% MgO + 17% S) — a fertiliser that besides potassium and sulfur contains magnesium. It is especially effective on magnesium‑poor soils (sandy and peaty). Magnesium is a component of chlorophyll, so its deficiency impairs photosynthesis.

• Potassium nitrate (46% K₂O + 13% N) — contains nitrogen and potassium in readily available form. Suitable for top‑dressing when you need to supply both potassium and a small amount of nitrogen. However, for beet in the second half of the season, this is not the best option, as nitrogen is no longer desirable.

Optimal Rates and Timing

Beet is a crop with high potassium demand. Potassium removal with the crop is 4–5 kg K₂O per tonne of roots with tops (Autko et al., 2012; Tarakanov and Mukhin, 2003). However, potassium should be applied considering soil fertility.

Average approximate rates (temperate climate, moderately supplied soils):

• Main application (autumn or spring before sowing): 90–150 kg K₂O/ha (about 1.0–1.8 kg per 10 m²).
• On poor soils, rates may be increased to 180–200 kg K₂O/ha.
• On rich humus chernozems — reduced to 60–90 kg K₂O/ha.

For home gardeners the optimal strategy:

• In autumn (under ploughing or deep digging) — apply the main part of potassium fertiliser (especially if using potassium chloride). Rate: 15–25 g/m² of active ingredient (K₂O). This is about 30–40 g/m² of potassium chloride or 25–35 g/m² of potassium sulfate.

• In spring before sowing — you can apply 1/3 of the total (provided you use a chloride‑free fertiliser) in rows together with phosphorus.

• First top‑dressing (3–4 true leaves stage) — give potassium in readily available form (e.g., potassium nitrate or potassium sulfate) at 10–15 g/m². This coincides with the period when nitrogen is still needed.

• Second top‑dressing (start of root formation, 20–25 days after the first) — increase potassium to 20–25 g/m². Use only chloride‑free forms (potassium sulfate, potassium magnesium sulfate). Do not add nitrogen in this feeding.

• Third top‑dressing (3–4 weeks before harvest) — optional, can be a foliar spray with potassium sulfate (0.5–1% solution) to improve storability.

Practical Recommendations

1. Potassium prefers neutral soil. On acidic soils, potassium uptake is poorer, so liming (to pH 6.0–7.0) is advisable before application. However, lime and potassium fertilisers should not be applied simultaneously — lime first, then potassium after 2–3 months (Nonnecke, 1989).

2. Potassium and magnesium are a good pair. On sandy and peaty soils, deficiency of both is common. Using potassium magnesium sulfate solves this. If not available, alternate potassium sulfate with magnesium sulfate.

3. Apply potassium to sufficient depth — into the root zone (15–20 cm). Surface application is ineffective, especially in dry weather.

4. Combine potassium top‑dressing with irrigation. Potassium dissolves well in water, and it is better applied with irrigation water (fertigation) or worked into moist soil followed by loosening.

5. Keep in mind that sodium can partially replace potassium (more on this in Chapter 4). However, complete replacement does not occur — potassium remains critically important for quality.

6. Monitor plant condition. If yellowish‑brown scorch appears on the edges of lower leaves, it is a signal of potassium shortage. Immediately apply potassium top‑dressing using potassium sulfate or potassium magnesium sulfate.

Key Takeaways

• Potassium is the main element responsible for sugar content, density, and storability of beet.
• The greatest need for potassium is in the second half of the growing season, when the root is actively growing and accumulating reserves.
• For beet, chloride‑free forms (potassium sulfate, potassium magnesium sulfate) are preferred. Potassium chloride is best applied in autumn.
• Potassium rates should be higher than nitrogen and phosphorus, especially on light soils.
• A sign of proper potassium nutrition is firm, sweet roots with vivid colour and no wilting during storage.

In the next chapter, we will discuss why boron is the most critical micronutrient for beet and how its deficiency can completely wipe out your harvest.

Why Beet Has Such a High Boron Requirement

Boron is not a component of enzymes, but it performs several irreplaceable functions in the plant:

1. Carbohydrate transport. Boron participates in the formation and functioning of phloem — the tissue through which sugars move from leaves to the root. In boron deficiency, this transport is disrupted, and carbohydrates accumulate in leaves without reaching storage organs (Rana, 2018; Tarakanov and Mukhin, 2003).

2. Cell growth and division. Boron is needed for the synthesis of pectin substances that bind cell walls. It ensures elasticity and strength of tissues, especially in actively dividing cells — growing points, young leaves, and cambial rings of the root (Autko et al., 2012).

3. Cambium development. It is precisely in the cambial layers of the beetroot that cell division occurs, forming new rings. Boron is critical for these processes. In its deficiency, the cambium dies, leading to hollows and necrotic areas inside the root (Balashev and Zeman, 1981; Nonnecke, 1989).

4. Flower and seed formation. Boron is involved in fertilisation and seed development, but for commercial root production this matters only in seed‑growing.

Symptoms of Boron Deficiency

Boron is immobile — it does not move from old organs to young ones. Therefore, the first signs of deficiency appear on young, growing parts (growing point, young leaves).

On leaves:

• Young leaves in the centre of the rosette stop developing normally: they become small, curled, deformed.
• Leaf blades may take on a yellowish‑purple colour, veins thicken.
• In severe cases, the growing point dies, and the rosette looks like a “rosette without a centre” — leaves flattened, middle empty.
• Petioles may crack lengthwise and become brittle.

On the root:

• Hard, dry, dark‑brown or black spots (necroses) appear on the surface or inside the root. They are often located in the central part or in the cambial rings.
• On cross‑section, brown, corky areas are visible, which may merge into cavities.
• The root becomes deformed, with uneven, rough surface, often cracked.
• During storage, such roots rot quickly, as damaged tissues serve as entry points for pathogens.

Symptoms of heart rot may appear as early as mid‑season, but more often they become noticeable at harvest or during storage. The disease is particularly severe in dry, hot weather when boron availability in soil decreases (Rana, 2018; Balashev and Zeman, 1981).

Why Boron Deficiency Occurs

Even if boron is present in the soil, plants may suffer deficiency for several reasons:

• Alkaline soils (pH > 7.0) — in alkaline conditions, boron becomes poorly available. This is one of the most common causes of deficiency on carbonate chernozems and calcareous soils.
• Dry weather — boron moves in soil with moisture. In drought periods, roots cannot absorb it, even if it is present.
• Liming — excessive lime application sharply reduces boron availability. If you have limed, check boron levels.
• Sandy and peaty soils — boron is easily leached from such soils, and reserves are low.
• Organic fertilisers — fresh manure and some composts can bind boron, making it unavailable.

When and How to Apply Boron

Boron can be applied to the soil (main application) and via leaves (foliar sprays). The latter is more effective, as boron is quickly absorbed by leaves and does not depend on soil conditions.

Soil application (autumn or spring before sowing):

• Recommended rate: 1–2 kg of boron (active ingredient) per hectare. For gardeners, this is about 1–2 g of boron per 10 m².
• In fertiliser terms: boric acid (17% B) — 6–12 g per 10 m²; borax (11% B) — 9–18 g per 10 m².
• Important: do not exceed the rate! Boron excess is toxic to plants and can cause root burns. On light soils, reduce the rate.

Foliar top‑dressing (spraying on leaves) — the most reliable method:

• Solution concentration: 0.1–0.2% (10–20 g boric acid per 10 L water). To dissolve, first dissolve boric acid in a small amount of hot water, then add cold water.
• Timing: first spraying at 3–4 true leaves; second after 2–3 weeks (at the beginning of root formation). In dry, hot weather, an additional treatment can be done.
• Working solution consumption: about 1–2 L per 10 m².

Important: Boron treatments are best done in cloudy weather or in the evening to prevent rapid drying. Adding a spreader‑sticker (e.g., household soap 5–10 g per 10 L) improves effectiveness.

Practical Recommendations

1. Check soil pH. Optimum for beet is 6.0–7.0. If pH > 7.0, boron may be unavailable. In that case, foliar feeding is your main method.

2. Plan treatments in advance. Boron deficiency is easier to prevent than to cure. Even if you see no symptoms, a preventive treatment early in the season is worthwhile — especially on light, alkaline, or peaty soils.

3. Do not combine boron with lime. Liming and boron application should be separated in time (at least 2–3 months). It is better to lime first, then apply boron the following year.

4. Manage irrigation. In dry weather, boron availability drops. Maintain soil moisture at 75–80% of field capacity (Nonnecke, 1989). Sprinkler or drip irrigation helps dissolve boron and make it available.

5. Observe plants. As soon as you notice the first signs of deficiency (stopped growth of the central leaf, curling), immediately apply foliar boron. Quick response can save the crop.

6. Use compound fertilisers with boron. Some manufacturers produce fertilisers already containing boron (e.g., “Boro‑Mag,” “Mag‑Bor,” special NPK grades with micronutrients). This simplifies application, but dosage must be respected.

Key Takeaways

• Boron is a critical element for beet. Without it, formation of a full‑sized root is impossible.
• Heart rot is the typical symptom of boron deficiency. It appears as dry brown spots inside the root and often leads to complete loss during storage.
• Foliar feeding is the most reliable way to supply boron, especially on problem soils.
• Boron rates should be moderate — excess is toxic. Follow recommended concentrations.
• Prevention is simple and inexpensive: 1–2 sprays per season completely eliminate boron‑related problems.

In the next chapter, we will look at whether beet needs sodium and how this unusual element can improve growth and root quality, especially in arid regions.

Why Does Beet Like Sodium?

Sodium is not an essential micronutrient for beet in the sense that the plant would die without it. However, in its presence, beet shows noticeable improvement in growth and quality. This is due to several physiological features:

1. Osmotic regulation and water relations. Sodium participates in maintaining osmotic pressure in cells, helping the plant to absorb water from the soil more efficiently and retain it in tissues. This is especially important in dry weather or on light sandy soils where moisture evaporates quickly (Nonnecke, 1989; Tarakanov and Mukhin, 2003).

2. Partial replacement of potassium. In beet, as in some other plants of the family Chenopodiaceae, sodium can partially perform potassium’s functions — for example, in enzyme activation and maintenance of membrane potential. With adequate sodium, the potassium requirement decreases somewhat, although complete replacement does not occur (Autko et al., 2012).

3. Improved carbohydrate transport. Sodium promotes more efficient movement of assimilates (photosynthates) from leaves to the root. This can lead to increased sugar content and root mass (Balashev and Zeman, 1981).

4. Enhanced nitrogen use efficiency. Sodium helps the plant to better utilise nitrate nitrogen, which is especially important when using nitrate fertilisers (e.g., sodium nitrate) (Nonnecke, 1989).

Where and When Sodium Is Particularly Beneficial

The positive effect of sodium is not always and everywhere evident. It is most noticeable in the following cases:

• On light sandy and sandy‑loam soils, where potassium is easily leached and its content is often low. Here sodium can compensate for potassium deficiency.
• In arid regions (southern Russia, Central Asia, parts of the USA and Europe) where moisture deficit limits growth, and sodium helps plants use water more efficiently (Nonnecke, 1989; Gashash et al., 2022).
• On alkaline and carbonate soils, where availability of potassium and other elements may be reduced, and sodium helps improve soil structure.

In regions with adequate moisture and fertile loamy soils, the effect of sodium may be less pronounced or absent.

Sources of Sodium for Beet

There are several ways to supply sodium to beet:

1. Sodium nitrate (NaNO₃) — the oldest mineral fertiliser, containing 16% nitrogen and 26% sodium. This is an ideal source for beet, as it provides both nitrogen and sodium in readily available form. Moreover, sodium nitrate does not acidify the soil, unlike many other nitrogen fertilisers, which is beneficial on acidic soils (Nonnecke, 1989).

2. Table salt (NaCl) — the most accessible and cheap sodium source. However, its use requires caution, as excess chloride is harmful to beet (as to many other plants). Salt is recommended only on soils not suffering from salinisation, and at moderate rates (Tarakanov and Mukhin, 2003).

3. Sodium in compound fertilisers — some manufacturers include sodium in NPK blends for beet and other sodium‑loving crops. Check the label.

How to Apply Sodium: Rates and Timing

Sodium rates depend on soil fertility and potassium availability. Remember: sodium is not a substitute for potassium, but a supplement. Even with sodium, potassium fertilisers remain mandatory.

Approximate recommendations:

• Sodium nitrate — applied as a nitrogen fertiliser at 100–150 kg/ha (about 1–1.5 kg per 100 m²), which supplies about 15–25 kg sodium per hectare. Best applied in 1–2 top‑dressings in the first half of the growing season (until mid‑July).
• Table salt — applied in very small rates: 20–30 g per 1 m² (200–300 kg/ha) in dry form, preferably before sowing or at early growth. Some manuals mention up to 50 g/m², but this is risky (Balashev and Zeman, 1981).
• Foliar applications — sodium is rarely applied foliarly, as it is well absorbed through roots.

How Salt Helps with Weeds and Diseases

In some regions, old gardeners use a table salt solution for spraying beet. Salt at 3–5% concentration (300–500 g per 10 L water) can indeed kill small weeds and repel some pests. However, such a method is very risky: high salt concentration can burn beet leaves and damage the root system. Therefore, we do not recommend using salt for spraying. It is safer to apply it to the soil (Nonnecke, 1989).

Dangers of Excess Sodium

Although beet is tolerant to sodium, excess can be harmful:

• Soil salinisation. Accumulation of sodium in the soil degrades its structure, reduces water permeability, and can lead to salinisation, especially in arid regions.
• Calcium and potassium deficiency. Excess sodium competes with these elements for root uptake, potentially causing their deficiency.
• Phytotoxicity. At very high concentrations, sodium damages roots and leaves; plants yellow and growth slows.

Therefore, the recommended rates of salt and sodium nitrate must be strictly adhered to. Never apply sodium on saline soils or in regions irrigated with brackish water.

Practical Recommendations

1. Check soil potassium content. If potassium is sufficient (>150 mg/kg), the effect of sodium will be weak. If potassium is low, sodium may help — but only as a temporary measure, not a permanent solution.

2. Use sodium nitrate as a nitrogen fertiliser in the first half of the season. This gives both nitrogen and sodium without salinisation risk. Rate: 1–1.5 kg per 100 m² in one application.

3. When using table salt — apply only in dry form under digging or in rows before sowing. Rate no more than 20–30 g per 1 m². On light soils, the rate can be slightly increased; on heavy soils, reduced.

4. Observe plant response. If leaves become more succulent, bright green, and roots increase in size — sodium is beneficial. If signs of burn appear (leaf edges brown, roots die) — immediately stop application and water the soil generously.

5. Do not apply sodium in arid regions without irrigation. Sodium is absorbed only in the presence of moisture. In dry soil, it may accumulate to toxic concentrations.

Key Takeaways

• Sodium is not essential, but beet responds positively to it, especially on light soils and in arid conditions.
• The main effect of sodium is improved water relations and partial substitution for potassium in osmotic regulation.
• Best source is sodium nitrate (it provides nitrogen and sodium without chloride). Use table salt cautiously.
• Excess sodium is harmful — observe dosages and do not apply on saline soils.
• Sodium does not replace potassium, only complements it. Potassium remains the main element for root quality.

In the final chapter, we will combine all elements into a single system and describe how to organise feedings according to growth stages so that each element works at the right time with maximum efficiency.

General Principles of Stage‑Based Nutrition

1. Early period (from sowing to 3–4 leaves) — plants are small and consume little, but this is when the future yield is being laid. Phosphorus (for root system) and boron (for the growing point) are critically important. Nitrogen is needed moderately to avoid excessive top growth at the expense of roots.

2. Active leaf growth period (from 4–5 leaves to row closure) — beet builds its assimilatory apparatus. Nitrogen demand is at its peak. However, even in the middle of this period, you should start shifting the balance toward potassium and phosphorus to prepare the plant for root bulking.

3. Root bulking period (from the start of thickening to harvest) — the main task is to direct carbohydrates from leaves to the root. Nitrogen is minimised or eliminated. The main elements are potassium, boron (foliar), and in some cases sodium. This is when sugar content and storability are determined.

4. Final period (3–4 weeks before harvest) — all feeding stops, so that roots accumulate dry matter and prepare for storage. Excess moisture and nitrogen at this time are harmful.

Detailed Fertilisation Schedule (for temperate climates, open ground)

Summary Fertilisation Table (for gardeners)

Special Cases and Adjustments

• On light sandy soils — split all fertiliser rates into 2–3 applications to avoid leaching. Especially important for potassium and nitrogen.
• On peaty soils — increase potassium rates (up to 30 g/m²) and be sure to add boron and magnesium (potassium magnesium sulfate or magnesium sulfate).
• On alkaline soils (pH > 7.0) — use physiologically acidic fertilisers (ammonium sulfate, superphosphate) and definitely plan foliar boron applications, as soil boron is unavailable.
• In dry weather — combine all feedings with irrigation. Foliar treatments should be done in the morning or evening to avoid burning.
• When deficiency symptoms appear — promptly apply foliar spray with the corresponding element (nitrogen — urea 0.5%; potassium — potassium sulfate 0.5%; boron — boric acid 0.1–0.2%).

Key Takeaways

1. Never apply all fertilisers at once. Beet needs different nutrition at different stages. Follow the stage‑based schedule.

2. Nitrogen is for leaves, potassium is for the root. A shift toward nitrogen in the second half of the season is the main mistake of novice gardeners.

3. Boron is your insurance. Even if you see no problems, one or two preventive boron sprays early in the season will pay off in crop quality.

4. Sodium is a useful supplement, not a panacea. Use it on light soils or in drought, but do not forget potassium.

5. Foliar feeding is a quick way to correct deficiencies. It works several times faster than root application, but does not replace basic nutrition.

6. Stop feeding 3–4 weeks before harvest. This allows roots to accumulate sugars and prepare for storage.