Ash specific weight: wood and coal ash

Using wood and coal ash is an excellent way to improve soil structure, feed garden plants with necessary minerals and trace elements of natural origin without chemical fertilizers. The main thing to determine before taking such steps is what characteristics the soil has, which plants need feeding and which ash should be used accordingly.

What is the difference between wood and coal ash?

Gardeners most often use ash as a complex fertilizer, but depending on what burned, one or another type of ash will have a different chemical composition. There is no need to discuss the harm of ash left after burning garbage, plastic and other waste: it will not only fail to help, but can seriously harm plants. Wood ash, as well as ash from herbaceous residues, contains almost no chlorine, which is extremely useful for potatoes and berry crops, but it contains substances plants need, such as:

• potassium,

• phosphorus,

• magnesium,

• calcium,

• iron,

• sulfur,

• zinc and others.

In ash, potassium and phosphorus are in the most convenient form for plant absorption, so it can be sprinkled on soil before deep plowing or added directly to the hole before planting. But this applies only to wood ash and ash from herbaceous residues, such as sunflower, potato tops, cereals and so on.

Coal ash is poorer in potassium and phosphorus than wood ash, but it may contain silicon and calcium compounds. Its composition depends strongly on the coal and combustion conditions; unwanted impurities are possible, so it should not be used on garden beds without knowing its origin and composition. Sulfur in coal ash can contribute to acidification, so it is not used on acidic or light sandy soils.

How much ash should be added?

For a large harvest, fertilizers should be applied correctly, understanding their effect on soil and plants. Regarding soil type, the main rules are:

• The approximate application rate of wood ash depends on soil type and cultivated crops. Before regular application, it is better to consider soil acidity and recommendations for specific plants.

• Wood and grass ash is suitable for any soil type except solonetzic soils; it reduces acidity and improves structure. Fertilization should be carried out no more than once every 2-4 years.

• Ash is added to clay soils and loams in autumn before plowing, and to sandy and sandy-loam soils in spring.

• Peat and shale ash is added to reduce soil acidity because it contains a large amount of lime. The rate is 650 g per 1 m².

Use of coal ash

Low-quality coal can contain a lot of sulfur and unwanted impurities. Such ash is better not used for growing food crops.

Because rainwater stagnates on alkaline soils, adding coal ash to alkaline soil will greatly worsen its condition, and the chlorine salts formed will harm plants. Good-quality coal ash can significantly improve clay soil.

Sulfur from coal ash is needed by:

• onion and garlic,

• cabbage and horseradish,

• radish and swede.

Specific weight, density, of ash

For small amounts of fertilizer, small measures are convenient, for example:

• 1 heaped tablespoon of ash contains about 7 g, and a teaspoon contains 2-3 g,

• a matchbox contains 10 g,

• a 250 ml glass contains 100 g of ash,

• a 0.5 l jar contains 250 g,

• a liter jar contains about 0.5 kg.