Investigation of the Effect of Different Silicon Levels on Growth and Yield Characteristics of Quinoa Under Various Irrigation Regimes

Document Type : Research Paper

Authors

• Mohammad Azimi Gandomani ¹
• Mostafa Alinaghizadeh ²

¹ Department of Agriculture, Faculty of Technical and Engineering, Payame Noor University, Tehran, Iran. E-mail: Mohammad.Azimi@pnu.ac.ir

² Department of Agriculture, Faculty of Technical and Engineering, Payame Noor University, Tehran, Iran. E-mail: Alinaghizadeh62@pnu.ac.ir

Abstract

Keywords

• biological yield
• morpho-physiological traits
• panicle
• Water use efficiency
• yield index

Main Subjects

• ..

EXTENDED ABSTRACT

Introduction

Quinoa, recognized for its high nutritional value and resilience to adverse environmental conditions, has garnered significant attention from researchers and farmers alike. However, water scarcity and drought remain major challenges in cultivating and producing this plant in arid and semi-arid regions. The use of mineral elements such as silicon, known for its positive effects on enhancing tolerance to environmental stress, improving plant growth, and optimizing performance under water-limited conditions, has been proposed as an effective strategy. In this context, investigating the impact of different silicon levels on the growth and yield characteristics of quinoa under various irrigation regimes can provide valuable insights into optimal water resource management and the use of supplemental nutrients to enhance agricultural productivity.

Materials and Methods

 This study aimed to investigate the morpho-physiological and yield responses of quinoa to silicon fertilization under drought stress conditions at the research farm of Payame Noor University, Gandoman Center, located in Chaharmahal and Bakhtiari province during the 2023-2024 growing season. The experiment was conducted as a split-plot design within a randomized complete block design with three replications. Irrigation was applied at four levels in the main plots (40%, 60%, 80%, and 100% of field capacity), and silicon fertilization was applied at four levels (0, 1, 2, and 3 liters per hectare) in the subplots. To apply drought stress, field capacity was first determined. For this, a 2 × 2 m plot was prepared and filled completely with water. It was then covered with plastic to ensure full saturation of the soil. After 24 hours, when water in the larger soil pores was removed by gravity, the plastic was removed, and a soil sample was taken. The sample was weighed and then dried in an oven at 105°C for 24 hours. The sample was reweighed to calculate the evaporated moisture. The product Totale Silício®, manufactured by Fertiláqua in Brazil, was used as the source of silicon. This product contains 750 grams of SiO2 and 45 grams of K2O per liter, and is a liquid suspension with a density of 1.20 grams per liter. Silicon fertilizer was applied in liquid form according to the experimental treatments. Data analysis was performed using SAS software version 9.4, and means were compared using LSD test at the 5% significance level. Graphs were created using Excel software.

Results and Discussion

The results showed that the highest plant height (105.5 cm), 1000-seed weight (3.28 g), grain yield (1868 kg. ha-1), and biological yield (4690 kg. ha-1) were achieved with 100% field capacity and 3 liters per hectare of silicon. Additionally, the highest harvest index (52.1%) was observed with 60% field capacity and 1 liter of silicon, while the highest water use efficiency (1.14 kg.m³) was recorded with 40% field capacity and 3 liters per hectare of silicon. In the 100% field capacity irrigation regime, the grain yield with 3 liters per hectare of silicon was 3%, 15%, and 49% higher compared to treatments with 2 liters, 1 liter, and no silicon, respectively. In the 40% field capacity irrigation regime, this increase for different silicon treatments compared to the maximum and minimum levels was 2%, 11%, and 89%, respectively. Furthermore, comparing grain yield between the 100% and 40% field capacity irrigation levels showed increases of 49%, 48%, 45%, and 90% for 0, 1, 2, and 3 liters of silicon per hectare, respectively. Silicon improved traits at all irrigation levels, but had a more positive effect on leaf area index, number of seeds per panicle, and water use efficiency at the 40% irrigation level compared to the 100% field capacity irrigation treatment.

Conclusion

The results of this experiment generally indicated that water scarcity reduces growth characteristics, yield, and nutrient content in quinoa leaves. In contrast, silicon fertilization mitigated the negative effects of drought. At all irrigation levels, silicon fertilization improved various plant traits, particularly leaf area index, number of seeds per panicle, leaf phosphorus, leaf nitrogen, and water use efficiency. This improvement was more pronounced at the 40% field capacity irrigation level compared to the 100% field capacity irrigation treatment. Overall, while quinoa shows relative drought resistance, the best performance for this plant was observed under 100% field capacity irrigation with 3 liters per hectare of silicon. With the application of 3 liters of silicon per hectare, quinoa production has significantly increased, resulting in a net profit of 267,600,000 IRR higher compared to when silicon is not applied.

Author Contributions

1 and 2: All authors contributed equally to the conceptualization of the article and writing of the original and subsequent drafts.

Data Availability Statement

Data available on request from the authors.

Acknowledgements

The funding for this research was provided by the budget allocation for project No. 6190/09/11/D/400, approved by the Research Council of Payame Noor University, for which we hereby express our gratitude.

Ethical considerations

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

Conflict of interest

The author declares no conflict of interest.