The best fertilizer for cabbages should be that which satisfies the nutritional requirements of the plant. To thrive, cabbages require several nutrients such as nitrogen, phosphorus, boron, zinc, iron, and manganese. To know which garbage fertilizer to use, you must identify whether your cabbages suffer from nutrient deficiency through a soil test.

This way, when you identify a deficiency, you must add specific nutrients to the soil to rectify this problem. One advantage of adding specific nutrients to the soil is reducing the risk of over-fertilization. 

Also, by adding specific nutrients, you save on money. Take an example of a farm that requires nitrogen, but the farmer goes on and buys a fertilizer bag that contains nitrogen, phosphorus, and potassium.

This farmer risks overfertilizing his farm by introducing excess phosphorus and potassium, decreasing yields instead of increasing them. So how do you know whether your cabbages are nutrient deficient?

Identifying Nutrient Deficiency in Cabbages

Nitrogen

Nitrogen is important because it increases yields. It does this by ensuring the cabbages have a big leaf size, increasing photosynthesis. It is also important to note that nitrogen helps increase the size of the cabbage head, increasing its marketability. 

Nitrogen deficiency can be detected by observing the leaves. If the leaves are chlorotic {have a green-yellow color}, your farm is nitrogen deficient. The chlorosis will start from older leaves and gradually spread to the entire plant. Because the plants are nitrogen deficient, they will suffer from stunted growth, and the older leaves will start to decay.

Several factors can cause nitrogen deficiency, and  the most common factors are:

• Drought conditions
• Planting in sandy or light soils
• Growing fast-growing varieties
• Growing in soils with low organic matter

Phosphorus

Phosphorus has three main benefits. First, it increases the marketability of the cabbages because of their good size, and second, it speeds up the growing process. One main symptom of phosphorus deficiency is that the cabbage has stunted growth.

Phosphorus deficiency can be caused by planting in soils rich in iron or soil with low organic matter. 

Potassium

Potassium is important to cabbage because it helps them become drought and cold-resistant. Also, potassium increases the biomass of the plant as well as the head weight. As a result, your farm will benefit from increased yields. Another benefit of potassium is that it enables cabbages to mature evenly, increasing their marketability.

One main symptom of potassium deficiency is the presence of withered necrotic border zones that are light brown. If potassium deficiency is not controlled on time, the necrosis will spread from the edge to the middle of the leaves,  destroying your farm.

Several factors can cause potassium deficiency:

• Planting in magnesium-rich soils
• Growing cabbages in heavy clay soils
• Plating during drought
• Excessive rainfall that causes leaching

Magnesium deficiency

Magnesium is important because it improves the storage capabilities of cabbages. Simply put, magnesium makes it possible for you to store cabbage for long periods without them getting spoilt. Another reason you should ensure that your farm is not magnesium deficient is that magnesium increases the photosynthetic activity of cabbages.

As a result, your cabbages will be healthy and consistently grow throughout the growth cycle.

To identify magnesium deficiency, you will have to look at the older leaves. Older leaves will have chlorosis signs between veins, affecting the leaf margin. Affected areas turn yellow, which later turns red or orange.

It is important to note that magnesium deficiency does not affect big Leaf veins, so do not be surprised when the veins remain green.

Magnesium deficiency can be caused by several factors, the most common being plating in soils with excess potassium. Other factors that can cause deficiency are: 

• Planting during the cold season 
• Growing in acidic soils
• Planting in sandy soils

Calcium deficiency

Calcium is important because it promotes good root development and makes Cabbages tolerant to abiotic and biotic stress. It also prolongs cabbage’s shelf life, which is good, especially if you transport cabbages for long distances.

The easiest way to identify calcium deficiency is by observing the tips of the leaves. The leaf tips have necrotic lesions, which create a tip burn perception. This deficiency can be caused by several factors, the most common being planting in soils rich in sodium and aluminum. Other factors are:

• Having a large cabbage fruit
• Drought conditions
• Planting in soils with high amounts of potassium and nitrogen’
• Planting in acid peat soils

Zinc deficiency

Zinc is important because it increases the stress tolerance levels of cabbages. The nutrient is also important for internode elongation and photosynthesis. Zinc also helps cabbages absorb more sugar and vitamin C from the soil, increasing your yields. Zinc deficiency is made worse by:

• Planting cabbages during the cold season
• Growing in soils rich with high PH
• Growing in soils rich in phosphorus
• Planting in organic soils

Increasing cabbage yields

The first rule of planting is to have a soil test done. The second rule of planting any crop is to ensure you only plant certified varieties with the highest return on investment. The seeding rate should always be between 250 – 400g per hectare.

The cabbage distance between one plant and another should be 50 centimeters between rows. Some of the most common cabbage pests you need to be concerned about are aphids and white butterflies. The white butterflies will lay their eggs on the cabbage leaves, and once they hatch, the larvae will feed on the leaves.

A cabbage disease you need to be aware of is the Alternaria leaf spot caused by a fungus known as Alternaria or brassicas. Other common diseases are Bacterial leaf spot disease, bacterial soft rot disease, and the blackleg. Blackleg is dangerous to crops because it destroys their roots.