1、Revisiting potassium

Potassium-induced benefits on crop yield and soil fertility are dependent on availability of soil indigenous K supply across wheat, maize, and rice production systems. To optimize K fertilization management, K fertilization should be prioritized for wheat and maize but not for rice.

2、Considering the Effects of Potassium on Manganese and Soil Fertility

Excessive potassium can also adversely affect nutrient availability, including the tie-up of boron and blocking of adequate manganese uptake from the soil.

3、(PDF) Effects of Agricultural Potassium Fertilizer Application on Soil

This review examines the impact and regulatory mechanisms of potassium fertilizer on the soil carbon cycle, discussing how potassium fertilizer affects soil carbon storage and flow...

4、Effect of Phosphorus and Potassium Fertilizers Application on Soil

At Assosa, a field experiment was conducted to determine how soil chemical characteristics and accumulation of phosphorus and potassium in potato tissue responded to phosphorus and potassium fertilizers application.

5、The Importance of Potassium (K) in Agricultural Soils

Where adequate levels K are not applied annually based on soil test results as either organic or fertilizer K, soil K levels will drop rapidly depending on soil type and K removals.

The potassium paradox: Implications for soil fertility, crop production

Contrary to the inculcated perception of KCl as a qualitative commodity, more than 1400 field trials predominately documented a detrimental effect of this fertilizer on the quality of major food, feed and fiber crops, with serious implications for soil productivity and human health.

What Does Potassium Do in Soil?

Soil erosion can occur when potassium and other fertilizers are not incorporated into the soil, leading to soil loss and decreased fertility. To minimize these risks, it’s essential to follow recommended application rates, timing, and soil testing protocols.

Soil potassium regulation by changes in potassium balance and iron and

Southern China’s paddy soils are poor in potassium (K) and rich in iron (Fe) and aluminum (Al) oxides, both of which are affected by fertilizer application. However, the response of soil K budget to long-term K fertilization and Fe and Al oxides remains unclear, especially in the subsurface horizons in different soil types.

P and K “fixation” in the soil: What you need to know

Fixation generally refers to the tendency for nutrients to become “tied up” in the soil and therefore less available to the crop. This happens when nutrients react with the soil, or ions in the soil solution, forming compounds or holding onto nutrients very tightly.

Fertilization with Phosphorus, Potassium, and Other Nutrients

Most soil P and K are not available to plants. Reactions involved in their cycle in the soil imply that a significant fraction of applied P and K is not absorbed by the crop. P and K fertilizer management should minimize the transformation of applied nutrients to nonavailable forms and maximize crop absorption.

Potassium fertilizer is a critical agricultural input that enhances plant growth rates and improves crop quality. if potassium fertilizer loses its effectiveness in the soil, plant development can be severely hindered. Below, we explain in detail why potassium fertilizer may fail to work properly in soil and how to address this issue.

Understanding Potassium Fertilizer

Potassium fertilizer contains elemental potassium, which primarily serves to replenish deficiencies of this essential nutrient in plants. Potassium plays a vital role in numerous physiological processes within plants, including photosynthesis, respiration, cell division, and overall growth. Thus, potassium fertilizer is indispensable for healthy plant development.

Reasons for Potassium Fertilizer Failure in Soil

The ineffectiveness of potassium fertilizer in soil can be attributed to the following factors:

1. Insufficient Soil Potassium Content: If the soil lacks adequate potassium, fertilizer efficacy diminishes. Plants require significant potassium uptake to sustain normal growth, and soil deficiencies directly limit their access to this critical nutrient.

2. Excessive Soil Potassium Ion Concentration: Overly high levels of potassium ions in the soil can toxicity plants, inhibiting growth. Excess potassium disrupts nutrient balance and harms root function.

3. Competitive Uptake by Other Ions: Soil ions such as calcium (Ca²⁺) and magnesium (Mg²⁺) may compete with potassium (K⁺) for uptake by plant roots. This competition reduces the availability of potassium to plants, weakening fertilizer effects.

4. Poor Decomposition of Soil Organic Matter: Incomplete decomposition of organic matter can "lock" potassium in the soil, rendering it unusable by plants. Organic acids released during decomposition may alter potassium speciation, making it less accessible.

5. Microbial Activity in Soil: High microbial activity can deplete soil potassium as microbes convert it into other forms (e.g., through metabolic processes). This reduces the amount of potassium available for plant absorption.

Solutions to Prevent Potassium Fertilizer Failure

To mitigate these issues, consider the following strategies:

1. Increase Soil Potassium Content: Apply potassium fertilizers or improve soil fertility with organic amendments (e.g., humic acid, green manure) to boost available potassium.

2. Adjust Soil pH: Optimize soil pH to reduce ion competition. For example, applying lime or ammonium sulfate can balance pH levels and enhance potassium availability.

3. Improve Soil Aeration: Enhancing soil structure through deep tillage or loosening increases oxygen flow, which supports beneficial microbial activity and potassium cycling.

4. Control Soil Temperature: High temperatures accelerate potassium oxidation, reducing its availability. Use shading or water spraying to moderate soil temperature and minimize losses.

5. Optimize Fertilization Timing: Apply potassium fertilizer during peak plant growth stages to align with demand. Tailor application methods based on soil fertility and crop requirements.

Potassium fertilizer failure in soil arises from a combination of factors, including low soil potassium, ion competition, microbial activity, and environmental conditions. By increasing soil potassium, adjusting pH, improving aeration, managing temperature, and timing fertilization correctly, farmers can maximize potassium fertilizer efficiency and ensure robust plant growth. Addressing these challenges holistically helps unlock the full potential of potassium for agricultural productivity.