Document Type : Research Paper

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Introduction

Soil degradation is considered one of the major global environmental challenges, with significant impacts on agricultural productivity, food security, and human health. The application of organic fertilizers is recognized as an effective strategy to improve the physical, chemical, and biological properties of soil, thereby enhancing agricultural sustainability. In this regard, compounds such as Zargreen, Molasses, and Vinasse, due to their rich content of essential nutrients, organic matter, and bioactive compounds, can improve soil fertility, stimulate plant growth, and increase crop yield. On the other hand, common bean (Phaseolus vulgaris L.) is one of the main sources of plant-based protein and holds a prominent position in cropping systems across different regions of Iran, including the Hidaj area of Zanjan province. This study was conducted to evaluate the combined effects of industrially-derived organic fertilizers on the growth, grain yield, and nutrient status of common bean in this region.

Material and Methods

This study was conducted in the summer of 2024 at the research farm of Royan Bazr Danesh knowledge-based company in Hidaj (Zanjan Province) using a randomized complete block design (RCBD) with 13 treatments and three replications. Soil samples were collected from a 0–30 cm depth before planting, and the chemical properties of the organic fertilizers were analyzed using standard methods. White bean (cv. Hidaj) was sown on July 10, and irrigation was performed using a drip system. Each experimental plot measured 5 m² and consisted of three rows, each 2.5 meters long. Treatments included various combinations of liquid organic fertilizers Zargreen, Molasses, and Vinasse, applied individually or in mixtures at different ratios 100–0–0 (Z1), 75–25–0 (Z2), 75–0–25 (Z3), 50–25–25 (Z4), 0–100–0 (M5), 25–75–0 (M6), 0–75–25 (M7), 25–50–25 (M8), 0–0–100 (V9), 25–0–75 (V10), 0–25–75 (V11), 25–25–50 (V12), and 0–0–0 (C13). Fertilizers were applied in two splits (August 19 and September 8) at a total rate of 90 liters per hectare.

Results and Discussion

The results indicated that different organic fertilizer treatments had a significant effect on growth features, yield, and nutrient uptake in white bean. The highest plant height (66.87 cm) and maximum dry weight of stem and leaves (23.02 g) were observed in the treatments with pure Zargreen (100-0-0) and the combination (75-25-0), respectively. The (75-25-0) treatment also showed the highest number of seeds per pod (30% increase compared to the control), 100-seed weight (10.97% increase), and grain yield (4680 kg/ha, 26.18% increase compared to the control). In contrast, the pure vinasse treatment (0-0-100) had the lowest values in most traits and negatively affected plant growth. In terms of nutrient content, the highest nitrogen concentration was observed in the (25-75-0) treatment (0.91%), and the highest iron concentration was found in the (75-25-0) treatment (117.37 µg/g dry matter). The combination of Zargreen and Molasses, due to their rich content of organic nitrogen, amino acids, carbohydrates, and microbial-stimulating properties, enhanced nutrient uptake and improved plant growth and yield. Conversely, the application of pure vinasse, due to its high salinity and nutrient imbalance, led to reduced water and nutrient absorption and ultimately suppressed plant growth.

Conclusions

The results showed that the combined application of organic fertilizers Zargreen and Molasses had a significant positive effect on the growth, yield, and nutrient uptake of white bean. Treatments containing Zargreen, especially (100-0-0), (75-25-0), and (25-75-0), produced the best improvements in plant height, dry weight, pod seed number, and grain yield. These combinations enhanced nutrient uptake by supplying amino acids, organic nitrogen, and soluble carbohydrates, which improved microbial activity and soil properties. In contrast, the sole use of Vinasse led to reduced growth and yield due to its high salinity and nutrient imbalance. Therefore, the Zargreen and Molasses combination is recommended as an effective strategy for sustainable agriculture and improved plant nutrition, whereas using Vinasse alone at high doses is not advisable and should be applied in controlled amounts combined with other organic fertilizers. These findings highlight the importance of selecting the proper combination and ratio of organic fertilizers for nutrient management and sustainable crop production.

Author Contributions

Conceptualization, E. G. and M. B.; methodology, E. G. and M. B.; software, E. G.; validation, E. G. and M. B.; formal analysis, E. G. and M. B.; investigation, E. G.; resources, E. G. and M. B.; data curation, E. G.; writing—original draft preparation, E. G. and M. B.; writing—review and editing, E. G., M. B., A. H., M. P. and S. A.; visualization, E. G. and M. B.; supervision, M. B.; project administration, M. B., A. H., M. P. and S. A.; funding acquisition, E. G. and M. B.

All authors have read and agreed to the published version of the manuscript.

Data Availability Statement

The data supporting the findings of this study are available in the manuscript. If the study did not report any data, you might add “Not applicable” here.

Acknowledgements

The authors would like to thank Zanjan Universities and Farhikhtegan Zarnam Research & Industrial Group for providing all the needed facilities.

Ethical considerations

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

Conflict of interest

The author declares no conflict of interest.