Document Type : Research Paper
Authors
- Yaser Azimzadeh 1
- Mokhtar Dashadi 2
- Amin Namdari 3
- Arash Mohammadzadeh 1
- Mozhgan Tabrizivand Taheri 1
- Halimeh Razmi 1
1 Dryland Agricultural Research Institute, Agricultural Research, Education and Extension Organization (AREEO), Maragheh, Iran
2 Dryland Agricultural Research Sub-Institute, Agricultural Research, Education and Extension Organization (AREEO), Kermanshah, Iran
3 Kohgilooyeh and Boyer-Ahmad province Agricultural and Natural Resources Research and Education Center, Agricultural Research, Education and Extension Organization (AREEO), Gachsaran, Iran
Abstract
Introduction
Nitrogen, as an essential nutrient, plays a pivotal role in plant vegetative and reproductive processes, directly influencing the synthesis of proteins, chlorophyll, amino acids, and nucleic acids. However, plant response to nitrogen fertilizer is influenced by variables such as environmental conditions, soil physicochemical properties, and the genetic potential of different cultivars. Insufficient or excessive nitrogen application can lead to reduced crop yield. Therefore, evaluating the response of lentil cultivars to different urea fertilizer levels across various regions of Iran and determining their economic optimal rate can pave the way for optimizing fertilizer use and achieving sustainable yields.
Materials and Methods
To investigate the response of lentil cultivars to different urea fertilizer levels in rotation with wheat under rain-fed conditions, a split-plot experiment arranged in a randomized complete block design with three replications was conducted in three regions (Maragheh, Sararood, and Gachsaran) during the 2023-2024 growing season. Treatments included lentil cultivars (Sana and Bilesavar in Maragheh; Bilesavar and Line 09S8322-04 in Sararood; Sepehr and Gachsaran in Gachsaran) assigned to the main plots and nitrogen levels (0, 25, 50, 75, and 100 kg urea ha-1) assigned to the sub-plots. Spring sowing was performed using a three-row ASKE seeder. To complement the analysis of variance, regression relationships were evaluated by analyzing the associations between different levels of urea fertilizer (independent variable) and agronomic traits (dependent variable) using quadratic nonlinear regression models.
Results and Discussion
In all three regions, the response pattern of most traits to different urea levels was parabolic, indicating the existence of an optimal point for fertilizer application. In Maragheh, the maximum grain yield for cultivar Sana (766 kg ha-1) was achieved with 52 kg urea ha-1, and for Bilesavar (603 kg ha-1) with 49 kg urea ha-1. In Sararood, Line S83 reached a yield of 2456 kg ha-1 with 62 kg urea ha-1, and Bilesavar yielded 2288 kg ha⁻¹ with 53 kg urea ha-1. In Gachsaran, cultivars Gachsaran and Sepehr yielded 862 and 788 kg ha-1 with 57 and 68 kg urea ha-1, respectively. The economic optimal dose in Maragheh for Sana and Bilesavar was 50 and 47 kg urea ha-1, respectively; in Sararood for S83 and Bilesavar, it was 60 and 49 kg urea ha-1, respectively; and in Gachsaran for Gachsaran and Sepehr, it was 45 and 43 kg urea ha-1, respectively.
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