1、pH Management and Plant Nutrition: Fertilizers

You will learn why water-soluble fertilizers are classified as acidic, neutral, or basic based on their fertilizer reaction in the substrate. Finally, with the information given in this article, you should be able to decide for yourself which fertilizers will work best for your growing conditions.

2、Thoughts on acidification of soils by nitrogen and sulfur fertilizers

Irrigation of acid-loving crops with alkaline water can raise pH and cause micronutrient deficiencies. Diseases like citrus greening (Huanglongbing) are more severe at higher soil pH values.

3、Manage pH using water 2017 Sponsors soluble fertilizers

Fertilizer acidity and basicity (lowers pH) or basic (raises pH) reaction in the media. You cannot tell how a fertilizer will react and affect media pH by measuring the pH

Effect of fertilizer potential acidity and nitrogen form on the pH

The potential of a water soluble fertilizer (WSF) to raise or lower substrate-pH is estimated in calcium carbonate equivalents (CCE) of acidity or basicity per unit mass of fertilizer.

Which Fertilizers Produce Acidity in Soil? A Scientific Approach with

Understanding which fertilizers lower soil pH can help farmers and gardeners manage soil conditions more effectively. This article explores which fertilizers produce soil acidity, how they work, and which Olimpum fertilizers are most suitable for acidifying soils.

(PDF) Fertilizer Use and Soil Acidity

Abstract and Figures soil fertility and the uses of fertilizer on acidity is explained. Soil acidity and nitrogen fertilizers (modified from (Davidson 1987)).

Fertilizers and Soil Acidity

The form of sulfur fertilizer added to soil can affect soil acidity, principally through the release of H⁺ ions by the addition of elemental S (S⁰) or thiosulfate (S₂O3²⁻, in ammonium thiosulfate – ATS) (Figure 3).

Soil Acidity: Causes

Rainfall is considered a natural cause of acidity because as water moves down through the soil profile, it has a slow but persistent acidifying affect. Weak acids are produced in the soil when plant residues and organic matter decompose.

Cause and Effects of Soil Acidity

The use of fertilizers, especially those supplying nitrogen, has often been blamed as a cause of soil acidity. Acidity is produced when ammonium containing materials are transformed to nitrate in the soil.

Inherent Factors Affecting Soil pH

In warm, humid environments, soil pH decreases over time through acidification due to leaching from high amounts of rainfall. In dry environments where weathering and leaching are less intense, soil pH may be neutral or alkaline.

Water-soluble fertilizers (WSF) are a highly efficient and eco-friendly agricultural practice, capable of providing essential nutrients to plants. users may occasionally encounter issues where the fertilizer exhibits acidity. The following sections explain the primary causes of this phenomenon:

1. Raw Material Quality Issues

• WSF formulations typically include inorganic salts such as nitrates, phosphates, and potassium compounds. Contamination during production or oxidation reactions during storage can introduce acidity.
• Certain raw materials may contain organic substances (e.g., sugars, fats), which decompose under high temperatures, releasing acidic gases that contribute to acidity.

2. Production Process Flaws

• Improper use of catalysts or additives during manufacturing may alter the chemical composition, affecting pH balance.
• Poor control over temperature, pressure, or reaction conditions during production can also induce acidity.

3. Storage Condition Problems

• High humidity, unsuitable temperatures, or poor packaging sealing can cause moisture loss, leading to precipitation of acidic components.
• Prolonged storage may trigger oxidation of organic matter, releasing acidic gases and further lowering pH.

4. Improper Application

• Excessive application or mixing WSF with alkaline soils can disrupt pH balance.
• Irrigation water containing calcium ions or other alkaline substances may neutralize or alter the fertilizer’s acidity.

5. Microbial Activity

• Soil microorganisms (e.g., bacteria, fungi) decompose organic matter, producing acidic byproducts that affect soil pH.
• If WSF contains such microorganisms, they may continue breaking down organics post-application, influencing soil acidity.

Solutions to Mitigate Acidity

1. Select high-quality raw materials to avoid contamination.
2. Optimize production processes, ensuring proper environmental controls to minimize pH shifts.
3. Improve storage conditions by maintaining ideal humidity/temperature and using airtight packaging.
4. Apply WSF judiciously—avoid overuse, and combine with complementary fertilizers to stabilize soil pH.
5. Regularly test soil pH and adjust fertilizer types/doses to maintain balance.
6. Enhance soil management practices to boost microbial activity and nutrient recycling.

acidity in water-soluble fertilizers arises from multiple factors, including raw materials, production methods, storage, application practices, and biological activity. Addressing these through rigorous quality control, optimized handling, and scientific soil management can prevent acidity issues and ensure fertilizer efficacy.