The Effects of Different Organic Fertilizer Sources on Potassium Forms and MF and IR Indices in Different Soils

Document Type : Research Paper

Authors

• Fatemeh Alikhani ¹
• Sareh Nezami ²

¹ College of Agriculture, Soil Science Department. Razi University

² Soil Science and Engineering department, College of Agriculture, Razi University, Kermanshah, Iran

Abstract

Keywords

• Chicken manure
• exchangeable potassium
• mealworm frass
• structural potassium
• Vermicompost

Main Subjects

• ..

Introduction

Rapid population growth and the increasing demands of society, along with the intensive production of agricultural products in arid and semi-arid regions, have led to the depletion and reduced availability of potassium (K) in Iranian soils. Additionally, the excessive use of chemical fertilizers and poor management practices in the agricultural sector have resulted in a significant shortage of organic matter in the country's soils. A study was conducted to investigate the effects of different organic fertilizers on the forms of K in two soils with varying characteristics.

Methods

This study was conducted in the laboratory of the Soil Science and Engineering Department at the Agriculture and Natural Resources Campus of Razi University in 2024. Initially, two soil samples with varying physicochemical properties were collected from the Agricultural Campus of Razi University and the Miandarband region of Kermanshah. After transferring the samples to the laboratory, the soils were air-dried and passed through a 2 mm sieve. Next, fertilizer samples were prepared. Following this, the physical and chemical properties of both the soil and fertilizer samples were determined using standard methods. Six types of organic fertilizers—cattle manure, poultry manure, and sheep manure, municipal waste compost, vermicompost, and mealworm frass—were then added to the soil samples at a rate of 1.5%. After the organic fertilizers were incorporated into the soil, the samples were incubated under controlled conditions for 60 days at field capacity (FC) moisture and a temperature of 25 °C. During this incubation period, the samples were weighed regularly, and their moisture content was monitored. At the end of the incubation period, we measured the soluble, exchangeable, and non-exchangeable K, as well as the structural K, mobility factor (M_F), and reduced partition index (I_R) of K.

Results

The results indicated that the addition of various organic fertilizers significantly impacted the forms of K, as well as the M_F and I_R indices, in both types of soil at the 5% probability level. In Agricultural campus soil, the treatments with poultry manure showed the highest levels of soluble K (173.8 mg kg⁻¹), followed closely by mealworm frass (167 mg kg⁻¹). The highest levels of exchangeable K (542 mg kg⁻¹) were also found in the mealworm frass treatment, while the non-exchangeable K reached its peak with mealworm frass at 1130.60 mg kg⁻¹. Additionally, structural K was highest in the cattle manure treatment at 6580.06 mg kg⁻¹. In Meandarband soil, soluble K was again highest in the poultry manure treatments (303.5 mg kg⁻¹) and mealworm frass (296.66 mg kg⁻¹). The highest levels of exchangeable K (1343.66 mg kg⁻¹) were recorded in the mealworm frass treatment, while the non-exchangeable K peaked in the poutry manure treatment at 2326.66 mg kg⁻¹. For structural K, the mealworm frass treatment had the highest value at 7502 mg kg⁻¹. In Agricultural Campus soil, the highest M_F values were observed with the poultry treatment (8.90%), followed by the mealworm frass treatment (8.43%) and the cow treatment (8.36%). In Meandarband soil, the highest M_F value was found in the mealworm frass treatment (15.56%), followed by the sheep treatment (14.26%). The lowest I_R values in Agricultural Campus soil were observed for the mealworm frass treatment (0.87) and the poultry treatment (0.86). In Meandarband soil, the lowest I_R value was recorded in the poultry treatment (0.79).

Conclusion

Generally, the treatments using mealworm frass, poultry manure, sheep manure, and cattle manure showed the most positive effects on K levels. In contrast, municipal waste compost and vermicompost had a lesser impact. Further studies under greenhouse and field conditions, along with soil mineralogical investigations, are recommended for these fertilizers.

Funding

This research did not receive any specific grant from funding agencies in the public, commercial, or not-for-profit sectors.

Authorship contribution

Conceptualization, Sareh Nezami; methodology, Sareh Nezami and Fatemeh Alikhani; software, Sareh Nezami and Fatemeh Alihani; validation, Sareh Nezami; formal analysis, Sareh Nezami; investigation, Fatemeh Alikhani; resources, Fatemeh Alikhani; data curation, Sareh Nezami and Fatemeh Alikhani; writing—original draft preparation, Fatemeh Alikani; writing—review and editing, Sareh Nezami; visualization, Sareh Nezami and Fatemeh Alikhani; supervision, Sareh Nezami; project administration, Sareh Nezami. All authors have read and agreed to the published version of the manuscript

Declaration of Generative AI and AI-assisted technologies in the writing process

No artificial intelligence tools were used in the article writing process.

Data availability statement

Data is available upon request.

Acknowledgements

We would like to thank the Honorable Vice Chancellor for Research of Razi University for financial and moral support in carrying out this research.

Ethical considerations

The authors avoided data fabrication, falsification, plagiarism, and misconduct.

Conflict of interest

The author declares no conflict of interest.