جستجوی مقالات مرتبط با کلیدواژه "جذب نیتروژن" در نشریات گروه "باغبانی"

To investigate the effects of common bean (Phaseolus vulgaris) and its residuals on agromorphological traits, yield, and qualitative characteristics of dragonhead (Dracocephalum kotschyi Boiss.) under intercropping conditions, and finally to evaluate the usefulness of intercropping compared to the monoculture of dragonhead, an experiment was conducted in a randomized complete blocks design with three replications at the research farm of Bu-Ali Sina University in Hamedan during growing seasons of 2018 and 2019. Experimental treatments included the additive intercropping of 0, 20 and 40% bean with dragonhead. The bean residuals were remained at the farm in the first year to determine its effects on quantitative and qualitative yield of dragonhead in the second year. Based on the results, the intercropping improved the agromorphological traits and yield of dragonhead compared to the control (dragonhead monoculture). The results showed that in the intercropping of 20% bean, the percentage and yield of essential oil, the phenol content, and the antioxidant percentage of dragonhead were higher than the control treatment, but flavonoids content was higher in the control. The results in the study of effects of bean residuals on the quantitative and qualitative traits of dragonhead in the second year showed that the meet of dragonhead needs in terms of nutrients like nitrogen increased its quantitative and qualitative yield compared to the control treatment. The relative yield of dragonhead was higher than bean, which indicated the profitability of dragonhead from intercropping with bean. In fact, the indices of land equivalent ratio (LER), competitive ratio (CR), and aggressivity (AG) showed the usefulness of dragonhead intercropping. Overall, the additive intercropping of 20% bean with dragonhead was identified as the superior treatment and can be used by farmers for organic production of dragonhead.

In this research the interaction effects of NaCl and nitrogen concentrations, on some physiological, biochemical, and growth characteristics of three olive (Olea europaea L.) cultivars (Abou-Satal, Arbequina and Conservolia) were investigated. The experiment was conducted as factorial with four NaCl levels (0, 40, 80, and 160 mM) along with three (NH4)2SO4  levels (0, 200, and 400 mg L-1) based on a completely randomized blocks design with three replications. Salinity had a statistically significant negative effect on responses considered, although the severity of the effect varied among cultivars. High concentration of salinity decreased the plant height, leaf number, root and leaf K/Na ratio, N absorption and concentration of root and leaf, K, Ca, Mg and P both of root and leaf while increased the root and leaf Na and Cl concentration. Increasing N levels to 200 mg L-1 has improved the plant height and leaf number. At 200 mg L-1 N concentration, Na, Cl and Ca root and leaf were decreased whereas, K/Na ratio, N absorption and concentration also K, Mg and P of root and leaf were increased. It can be concluded that under salinity condition increasing N concentration up to 200 mg L-1 in salt sensitive cultivars to salinity is favorite in counteracting the adverse effects of salinity but the further increase of N concentration (400 mg L-1) may be ineffective or harmful for the growth of olive plants. In this experiment, investigation cultivars responses to salinity showed that cv. Abou-Satal is a highly resistant at highest salinity level (160 mg L-1), also cv. Arbequina is semi-sensitive and cv. Conservolia is a sensitive to salinity condition.