Knowledge from Olle Garden Bed: How Calcium in Soil Helps Plants

In humans, calcium is a key component in building healthy bones and teeth. Calcium in soil plays an important role in the development of garden soil structure. For plants, calcium promotes the healthy growth of plants throughout the growing season. After all, it is an important macronutrient in plant nutrition profile. The following content also has some reference value for raised garden beds.

This article will outline calcium as a plant nutrient and help readers determine how to detect calcium deficiency. We will also discuss its role in soil structure. As with most soil related topics, variables such as climate, texture and organic matter, as well as other attributes, play a role.

When considering soil fertility, it is very important to understand the soil structure of the garden. Calcium is a nutrient that often attracts great attention on the Internet. It is suggested that gardeners should add eggshells and oyster shells to prevent the flower tip from rotting. In most cases, adding it to the soil will not solve the defect by correction alone.

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Let's take a closer look at this critical part of plant nutrition and discuss the right way to add calcium to the soil.

  1. Calcium as a plant nutrient

Calcium has many functions in plants. It helps plants build strong cell walls. Plant cell walls provide the rigid structure and protection required by plants. Calcium plays a role in the permeability of cell membranes. Strengthened membranes help plants prevent toxic compounds from penetrating cell walls. Calcium also activates certain enzymes involved in biological reactions in plants. Finally, it plays a role in cell division and cell elongation.

A key part of understanding calcium is how plants absorb this nutrient. First, we need to understand the function of xylem and phloem, that is, the vascular system of plants. The xylem is responsible for distributing water and dissolved minerals from the roots to the leaves through the stems. The phloem carries sugar and food from the photosynthesis area to other parts of the plant.

In addition to this brief explanation, the complex vascular system of plants is also involved. Calcium cations (positively charged ions) are absorbed from the young tissues of the root. The xylem then carries calcium from the roots to the plant. This is the key point for young roots, because young roots have more osmotic membranes than old root tissues.

1.1 Calcium demand

The amount of calcium required by plants varies from species and family to family. Monocotyledon plants (grasses) such as corn, sorghum and allium require a small amount of calcium. Garden crops of Brassicaceae (cabbage, broccoli, kale, kale, etc.) need more calcium. Trees need the most calcium. This is because calcium is important in the formation of woody trunks.

  1. Finding calcium deficiency

When it comes to nutrient deficiency, it is important to know how calcium interacts with each plant. Some nutrients show similar deficiency characteristics, but in different parts of the plant. For example, defects may only appear on old leaves, not new leaves. These small details are important when diagnosing defects.

A typical example of calcium deficiency is the end rot of tomatoes. In this case, the defect is obvious because the bottom of the tomato has a rotten appearance. Calcium is difficult to transfer to fruit, so defects can be seen at this location.

Growth points can also show defect characteristics. New leaves may stick together. Under the soil, the root will develop slowly due to lack of calcium. Needless to say, looking at growth points and fruits is a much easier way to diagnose defects than checking roots.

  1. The role of calcium in soil

Calcium is essential to a healthy soil structure. This is particularly important for a process called flocculation. During flocculation, clay particles are pulled together and separated from other soil particles. This can be seen in the most basic household soil tests, where the soil shakes in water. The clay is gathered together, and the water is less turbid than the soil with less aggregate.

Flocculation contributes to runoff and erosion because the water flowing from the farm is clearer and has less sediment. Compared with other cations (such as magnesium), calcium is the best at keeping these clay particles together, and magnesium also has a+2 charge. Magnesium and calcium usually shield each other in many aspects, but differ in plant function and flocculation capacity.

3.1 How calcium circulates

Calcium enters the soil in many ways. One method is to degrade minerals such as calcite, limestone and dolomite. These and other soil parent materials release calcium into the soil. Calcium is an essential alkali cation in cation exchange. Cation exchange capacity is the amount of cations that the soil can hold.

The exchange process occurs when cations (or positively charged calcium ions) exchange between soil particles and solutions. In addition to calcium, there are many cations at work, all of which have different exchange capacities. Cation exchange capacity is another way for plants to obtain calcium in soil.

The third main way for calcium to enter the soil naturally is through atmospheric sedimentation. Soot and ash from the atmosphere are deposited in the soil, and calcium is added to the soil in the process. Calcium can leave the soil in two ways. The first is leaching, because water will wash away calcium that does not adhere to clay particles. The second is through plants, which absorb calcium from the soil.

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  1. Why does your soil not lack calcium

Seeing the end of a flower rots may make you think your soil has no calcium. In most cases, this is not the case. Most soils have enough calcium to support the garden. The reason of flower tip decay may be due to insufficient and/or inconsistent watering in the root zone.

As I mentioned earlier, calcium is absorbed by the young roots of plants through water. Once the root cells mature, calcium is no longer absorbed. Continuous watering makes it easy for calcium to enter plants and fruits. In any case, most garden soils, matrix mixtures and general fertilizers contain calcium, so calcium deficiency is less likely.

One of the only cases where calcium may not be part of the soil structure is in highly acidic soils. Once the pH value of the soil is low enough (about 4.5 and below), aluminum (iron and manganese) toxicity will occur. In this case, the calcium in the soil is tightly fixed to the clay particles so that the roots cannot contact them.

This is usually easy to determine. When the pH value of the soil is acidic, it lacks several other minerals and nutrients, and the plant does not grow well. Soil testing is the only way to determine if your soil structure lacks calcium.

Extremely sandy soils may also result in calcium deficiency because of the lack of clay particles that can be used to bind calcium. It is unlikely that anyone will grow garden crops in this sandy soil. In acid and sandy soils, nutrient availability is generally low. The possibility of trying to grow is very low in both cases.

4.1 Lime soil

Although this is rare, there may be excessive calcium in some soils. The soil with high calcium carbonate content is called calcareous soil. The pH value of these soils is higher than 8.0, which will not significantly hinder the healthy growth of plants. It is worth noting that calcium is not the cause of the increase in pH. Carbonate in lime is the cause of the increase in soil pH, not calcium, which is often blamed.

  1. Treatment of calcium deficiency

Proper irrigation is the key to solving most calcium deficiency in gardens. If calcium is lacking for some reason, there are many options that can help. However, foliar spraying will not repair the tip rot in tomatoes. This is because deficiency does not exist in leaves, but in fruits.

5.1 Soil pH

Calcareous lime and dolomite lime are two main modifiers used to improve soil pH value. In the case of calcium deficiency, the soil is already extremely acidic. Of all calcium fertilizers, calcium lime is usually the best, depending on the situation. Agricultural lime will increase the pH of soil.

Lime is calcium carbonate, and the carbonate in this molecule is responsible for increasing the soil pH value. Dolomite is similar, but contains magnesium rather than calcium. As previously mentioned, calcium is responsible for the structure and flocculation in the soil. Adding only dolomitic lime can increase the magnesium content.

Calcium based lime is added to acid soil at regular intervals to increase the proportion of calcium. Garden lime has many choices, including hydrated lime or burnt lime - all of which add calcium to the soil.

5.2 Soil improver of non agricultural lime

Gypsum is a common soil conditioner. This calcium sulfate containing modifier is often promoted as a way of decomposing clay. Calcium sulfate does not have this ability, but it is a good correction for adding sulfur and calcium to the soil without significantly changing the pH value.

Bone meal is made from ground bone, which is another common calcium fertilizer improver that gardeners can use. It is an organic fertilizer containing calcium and other nutrients. It consists of less nitrogen and more phosphorus (3-15-0NPK), rather than other fertilizers, which contain more nitrogen. Bone meal is often touted as a way to promote crop fruiting and flowering.

Wood ash has long been used to fertilize crops. Wood ash fertilizer comes from the remains of burning wood products. Hardwood ash contains a lot of calcium carbonate. If the soil is already at an acceptable pH, the application of excessive wood ash will cause the pH to be higher than the optimum pH value.

Calcium chloride or chlorine is an easily soluble option and is commonly used as a calcium fertilizer. However, I do not recommend using it as fertilizer because high concentrations of chlorine are harmful to plants. Using calcium chloride as a source of calcium is a bad idea, but when talking about calcium improvers, it is often touted as a viable option. Considering all the information and modification options, please select another option.

Similarly, calcium nitrate is an inorganic fertilizer used to add calcium to the soil. Calcium nitrate is composed of limestone, nitric acid and ammonia. Although this kind of fertilizer does add calcium to the soil, it is better to choose the fertilizer made of organic substances rather than the chemical substances that can flow away and change the soil pH more easily.

Other modifiers, such as calcium acetate, soft rock phosphate and colloidal phosphate, are available calcium modifiers. Some of these are contained in common fertilizer mixtures. Most are not developed for the primary supply of calcium, but they have additional benefits.

5.3 Eggshells and oyster shells

These two are often touted as fertilizers, which can be simply thrown into the garden like bone meal or wood ashes. Although egg shells and oyster shells do contain calcium, they can only be used for plants after being decomposed. Plants absorb calcium as cations, not through compounds. This means that calcium needs to be separated through reaction over time before it can be absorbed by roots and plant tissues.

This process takes time, so calcium is not available throughout the growing season. The ground eggshell degrades faster than the whole eggshell, but it still takes some time to decompose. Other organic amendments can add calcium to soil more quickly and effectively. However, you can add these to your garden to support the growth of the next season.

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Calcium is an important component of plant nutrition, which can promote strong growth, cell division, cell elongation and enzyme activation. In general, like many soil problems, calcium is distorted by many people on the Internet.

Eggshells are constantly being promoted as a solution to end rot. Although eggshells will not harm the garden in the end, they will not help immediately. Many of us apply garden lime to the soil, which will increase calcium, but the key is continuous and adequate watering.