فهرست مطالب اردشیر طاهری نژاد

Camelina (Camelina sativa L.) is a plant with oil seeds suitable for rainfed cultivation. In this situation, the use of appropriate amounts of sulfur and nitrogen fertilizers play an important role in plant growth. Therefore, an experiment was carried out in factorial based on a completely randomized design in order to investigate the effect of these fertilizers on the growth of Camelina var. Sohail in three replications in 2021-2022. The factors included sulfur (0, 50, 100 and 150 kgha-1) from bentonite sulfur source and nitrogen (0, 40, 80 and 120 kgha-1) from urea source. The values of root volume and length, no. pods plant-1 and no. seeds pod-1 increased with the use of sulfur, but there was no significant difference between 100 and 150 kgha-1 of sulfur. The highest values of root volume, root height, root dry weight, allometric coefficient, shoot dry matter, seed yield, no. pod plant-1, no. seeds pod-1, 1000-seeds weight and the water use efficiency were obtained using 120 kg ha-1 of nitrogen. It increased root dry weight, grain yield and WUE by 55, 43 and 49% compared to the control, respectively. The interaction effects between the treatments on leaf area, root surface and plant height traits were significant. The highest amount of these traits was in sulfur and nitrogen treatments 150 and 120 kgha-1, respectively. In general, the results showed that in rainfed conditions, increasing the amount of nitrogen fertilizer increased root growth, seed yield and water use efficiency, but sulfur fertilizer had no significant effect.

Nitrogen is a vital and important element for the plant and is available by chemical or biological process. The contribution of nitrogen fertilizer to performance improvement in various studies has been reported to be between 30-50%. Koocheki et al. (2017) reported that the levels of nitrogen fertilizers used in experiments for wheat in the range of 20-250 kg.ha-1 increased wheat yield by 2477 kg.ha-1 compared to control treatment. Biodegradable fertilizers (especially Azotobacter) has been reported positive because they have great potential to improve the nutrition of plants and replace chemical fertilizers, and can minimize or completely eliminate the use of chemical fertilizers and reduce environmental hazards, improve soil structure in cereal, dissolve phosphate and increase growth via absorption of mineral elements. Azotobacter, one of the most reputed free-living bacteria that stabilizes nitrogen in the air, which by using different mechanisms, increases the production of auxin hormone and the development of the plant's root system (increasing root area with more growth), and ultimately helps increase the yield of crops and orchards. The amount of nitrogen consolidated by 20 to 40 kg.ha-1 per year is estimated for cereals such as wheat, corn, sorghum, millet and rice, with a yield increase of 7-12% and a maximum of 39% in these plants.

This experiment was conducted on irrigated barley (Hordeum vulgar v. Bahman) in a farm in the Songhor town, Kermanshah Province, as factorial based on completely randomized block design (CRBD) with three replications during 2014-2015. Factors including Azotobacter chroococcum (0, 100 and 200 g.ha-1) and nitrogen fertilizer from urea source (0, 50, 100, 150 and 200 kg.ha-1). In this test were studied LAI, number of tillers, shoot dry weight, hectoliter weight, protein content, biological yield, grain yield, harvest index, number of spikes.m-2, number of seeds per plant and thousand-seed weight traits. Sowing date was 19 November, 2014. Azotobacters used as inoculate with seed treatment and urea fertilizer at planting time just one-third and two-thirds were stem elongation.

Analysis of variance showed that the effects of azotobacter and nitrogen as well as interactions between them were significant on all traits. The maximum amount LAI, tillers, shoot dry weight, hectoliter weight, protein content (12.5%), biological yield, harvest index, number of spikes, number of grains per spike, thousand seed weight and grain yield (871 g m-2) were obtained in treated with 200 g.ha-1Azotobacter and 200 kg.ha-1 N With the increase the amount of inputs also increased attribute values. Considering the cost of the inputs and amount of grain yield and protein, the consumption of 100 g.ha-1Azotobacter and 100 kg.ha-1 N about 834 g.m-2 and 26%, respectively, had the most economic output and did not significantly different with maximum consumption of them. Generally, the results showed that the effect of industrial nitrogen on all traits was more than Azotobacter, but optimal use of biological and chemical fertilizers combined treatment with low doses (100 g inoculated with 100 kg.ha-1 N), also had the significant and positive effect on morphological traits and yield. So it may be partly replaced urea fertilizer consumption with Azotobacter.

The results of this experiment showed that the highest grain yield (871 g.m-2) was obtained from the combined application of 200 g.ha-1 biomass with 200 kg.ha-1 N. In general, with increasing amount of nitrogen from type of urea, the grain yield was between 20 and 71% and the grain protein content was between 20 and 32%, but with the increase of azotobacter (alone), the grain yield increased between 17 and 42%, and the grain protein was between 5 and 10 Percentage.

While Azetobacter bacteria in the rhizosphere, in addition to providing a part of the nitrogen will be production of crop growth promoting, root growth and yield. Acording to this, two experiments were in order to the effects of Azotobacter and nitrogen carried out on irrigated barley (Bahman variety) on root and shoot growth at booting stage (experiment 1) and root and shoot growth and also grain yield at ripening stage (experiment 2) in pot condition in Songhor town (cold area), Kermanshah Province as a factorial in based a completely randomized design (CRD) with three replications during 2014-2015. Factors included Azotobacter chroococcum (0, 100 and 200 g ha-1) and nitrogen fertilizer (0, 50, 100, 150 and 200 kg ha-1) from urea source. Analysis of variance showed that the effects of Azotobacter and nitrogen as well as interactions between them on all traits at two experiments were significant. The maximum of root traits, shoot dry weight and grain yield (21.77 g pot-1) at booting (experiment 1) and maturity stages (experiment 2) obtained at Azotobacter (200 g ha-1) and Nitrogen (200 kg ha-1) and declined amount of traits with decreased amount of treatments. But, this grain yield was not significant difference with Azotobacter (100 g ha-1) and nitrogen (100 kg ha-1) treatment (20.85 g pot-1). Generally, the results of this test showed that the consumption of 100 g ha-1 Azotobacter has been saved about 100 kg ha-1 nitrogen and reduced bio-environmental problemes.