How to increase the acidity of soil (how to make the soil acidic)

Acidic Soil Introduction

Soil can be divided into acidic soil, neutral soil and alkaline soil.

To distinguish the acidity and alkalinity of soil, we usually use chemical methods to measure the pH value of the soil solution. Generally speaking, the pH value between 6.5 and 7.5 is neutral soil; below 6.5 is acidic soil; and above 7.5 is alkaline soil.

So acidic soil refers to soil with a pH value less than 6.5, among which a pH value <4.5 is extremely acidic, 4.5-5.5 is strongly acidic, 5.5-6.0 is acidic, and 6.0-6.5 is weakly acidic.

Since soil can be acidic, neutral or alkaline, some plants in nature prefer to grow in acidic soil, while others prefer to grow in alkaline soil. Most crops prefer neutral soil.

Crops such as cotton, wheat, corn, potatoes, sweet potatoes, and watermelons are suitable for growing in slightly acidic soil.

Other flowers and trees such as azalea, lily, heather, marigold, honeysuckle, cedar, oak, etc. also grow well in slightly acidic soil. There is also a fruit tree, blueberry, which prefers to grow in a strongly acidic soil with a pH value of 4.5-5.5.

Various crops that prefer slightly acidic soil tend to grow poorly in neutral or alkaline soil, so it is necessary to improve and adjust the soil acidity for these crops.

How to make the soil acidic?

1. We have found in agricultural production that if sulfur-based fertilizers, potassium sulfate-type compound fertilizers and water-soluble fertilizers are applied year after year , the soil will easily become acidic.

However, this process is relatively long and takes several years. If you want to achieve your goal in a short time, this method is not suitable. It can be used in daily crop planting to maintain acidity.

2. Use ferrous sulfate to quickly make the soil acidic

Ferrous sulfate, commonly known as green vitriol, is often used in agriculture to improve soil and adjust acidity. When green vitriol is applied to alkaline soil, it reacts chemically with calcium carbonate in the soil and releases carbon dioxide gas, which can make the soil looser.

The iron element in ferrous sulfate is an important element for plants to synthesize chlorophyll, and it is effective in improving nutrient deficiency symptoms such as yellow leaves at the top of crops.

  Ferrous sulfate improves soil pH quickly, but its effect is short-lived and requires frequent application.

3. Apply sulfur powder

The effect of sulfur on regulating soil acidity is very long-lasting and stable. Its working principle is that after sulfur is applied to the soil, it is oxidized by sulfur bacteria into sulfuric anhydride, which is then converted into sulfuric acid, which then plays a role in regulating acidity.

It has been reported that applying about 130 grams of sulfur powder per square meter of soil can reduce the soil pH value by about 1.

This process is also relatively slow and long-lasting. Generally speaking, after sulfur is applied to the soil, it takes 40-80 days for it to decompose and regulate the soil. Therefore, when using sulfur powder to regulate the soil, you need to reserve enough time in advance.

4. Apply more acidic peat, pine needle soil or mineral humic acid with high organic matter content.

Crop straw, leaf humus, and bark can also be used, but they must be fully decomposed before use. Simply changing the soil acidity by chemical methods can easily deteriorate the soil environment.

Applying peat, decomposed straw, etc. not only helps to lower the soil pH, but also increases soil organic matter, changes soil properties, makes the soil looser, more breathable, and more suitable for crop growth .