The combined effect of nitrogen fertilizer and sowing season on response to water-limited stress in barley (Hordeum vulgareL.)

Abstract

A field experiment was carried out for over two seasons (autumn and spring) as a split–split plot scheme based on a randomized complete block design with three replications. The main plots included two irrigation levels of the maximum available water depletion (maximum allowable depletion (MAD)) of 55 and 85% as non-stress and drought-stress environments, respectively, and the subplot accommodated two levels of nitrogen (0 and 62.5 kg N/ha, urea fertilizer); also, 20 barley genotypes were assigned to the sub-subplots. The biplot analysis of both sowing seasons showed that grain yield (GY) had a high positive correlation with total biomass (TB), whereas it had a high negative correlation with proline and total soluble carbohydrate as drought-tolerance-determinant characteristics. The genotypes which had the lowest and highest GY ranked significantly (P ≤ 0.01) different with changing the sowing season under each irrigation level, indicating a larger plant interaction and non-stability in response to the season change (about two-fold), as compared to the change in the irrigation conditions. It could also be concluded that barley genotypes might experience a higher decrease in GY and sensitivity to water deficit in the autumn sowing season, as compared to the spring planting season, which was also intensified by nitrogen application. However, the response to nitrogen application depends on the plant genotype.

Responses of Two-Row and Six-Row Barley Genotypes to Elevated Carbon Dioxide Concentration and Water Stress

“…JMP (ver. 16) software was used to cluster genotypes and measure traits with heat mapping according to Ward's method [29].…”

“…The plant material used in this experiment consisted of four barley genotypes including Goharan and Mehr (six-row) and Behrokh and M9316 (two-row), which were selected based on a previous comprehensive field evaluation [16] (Table 1). The experiment was conducted using a split factorial-based randomized complete block design with three replications.…”

“…Sampling was performed at the stage of spike emergence on the leaves of five randomly selected plants on [13][14][15][16] May 2018, and harvesting of the plants was performed at the time of physiological maturation on 16-19 June 2018. The samples for shoot and root weight determination were collected from harvested plants.…”

Effect of Arbuscular Mycorrhizal Fungi on Nitrogen and Phosphorus Uptake Efficiency and Crop Productivity of Two-Rowed Barley under Different Crop Production Systems

“…As a result of nitrogen fertilization, plants during the vegetative phase were likely to grow at a faster rate [31]. When the nitrogen level of barley plants was increased, the plant height increased primarily because nitrogen stimulated metabolic activity, resulting in an increase in metabolites amount, which in turn resulted in internodes' elongation and increased plant height by enhancing the plant availability for nitrogen [32]. In light of the relatively high height of the barley plant, a significant high concentration of photosynthetic products was found, and the plant height correlated positively with total biomass yield (r = 0.788, p < 0.001; Figure 4).…”

“…Furthermore, in the present research, the leaf area index (LAI) was linearly related to seed production (r = 0.682, p < 0.001; Figure 4). As a result of increased photosynthesis, an increase in photosynthetic products was produced, which resulted in an increase in biomass and seed yield [32,41,47].…”