جستجوی مقالات مرتبط با کلیدواژه « fertilization » در نشریات گروه « زراعت »

In order to investigate the effect of water stress and the application of potassium sulfate fertilizer on some growth characteristics of "Zahedi" date palm tissue culture-derived plants, this research was conducted as a factorial experiment based on a Randomized Complete Block Design with three replications on 45 plants. Water stress at three levels (Irrigation to the amount of 100, 80 and 60% of cumulative evaporation from Class A evaporation pan) and potassium sulfate fertilizer at five levels (zero, foliar application 2 g L-1 and 4 g L-1, soil application 50 g and 100 g for each plant) were applied to the plants. At the end of the experiment, the growth characteristics including trunk circumference, number of leaves, length and width of leaves, number of leaflets, length and width of leaflets, fresh and dry weight of aerial parts were measured and subjected to statistical analysis. The results showed that the increase in water stress had a significant negative effect on all vegetative growth traits, while the application of potassium sulfate moderated the effects of water stress. At the highest level of water stress (Irrigation to the amount of 60% of the water requirement) without application of potassium, the fresh and dry weight of aerial parts was recorded at 590 and 243 g respectively, but with the soil application of 100 g potassium sulfate at the same level of water stress, the fresh and dry weight of aerial parts increased significantly to 706 and 346, respectively. In this research, the soil application of potassium sulfate fertilizer had better effects on the growth characteristics of date palm plants than the foliar application method. In all levels of water stress, the application of potassium sulfate fertilizer, especially in soil application of 100 g for each plant, increased vegetative growth and fresh and dry weight of the date palm plant and improved its resistance to water stress.

In order to investigate the effects of nitrogen rate and time of irrigation on the grain yield and grain yield components of wheat, one experimental as split plot was carried out as split plot design based on randomized complete block design with four replications in research farm of Aliabad Katoul Emam Khomeini agriculture high school during 2018-2019 and 2019-2020. Irrigation time was in main plot (no irrigation, irrigation at stage 33 zadoks, irrigation at stage 70 zadoks) and nitrogen rate was in sub plot (zero, 57.5 kg N/ha, 115 kg N/ha from urea source). Significant interaction wasn’t observed between irrigation treatments and nitrogen rates in almost all traits. The highest yield was obtained by using a supplementary irrigation in stage 70 of Zadox and consumption of 115 kg of pure nitrogen. Grain yield had a positive correlation with biological yield, spike length, spike weight, number of seeds per spike and seed weight per spike. Factor analysis revealed that the first two factors explained 74.5% of the total variation. The results of stepwise regression analysis showed that only the spike weight trait entered the model and alone justified 80.7% of the grain yield variation.

A two-year experiment (2017-2019) was conducted at Karaj, Iran, to investigate the effect of ammonium and potassium sulfates on the physiological traits and seed and oil yields of camelina under late-season deficit irrigation conditions. The experiment was carried out as a split plot-factorial in a randomized complete block design with three replicates and irrigation regimes (full irrigation, restricted irrigation from flowering and siliqueformation stages) as the main plots and a combination of ammonium sulfate (0, 25, 50, and 75 kg ha-1) and potassium sulfate (0, 25, 50, and 75 kg ha-1) fertilizers as the subplots. Leaf relative water content, canopy temperature, stomata resistance, proline, carbohydrate, chlorophyll and seed and oil yields were affected by the three-way interaction between irrigation regime, ammonium and potassium sulfates. Camelina seed and oil yields were 2470 and 833 kg ha-1 in full irrigation, 613 and 118 kg ha-1 in restricted irrigation from the flowering stage, and 1320 and 407 kg ha-1 in restricted irrigation from the silique formation stages, respectively. Application of ammonium and potassium sulfates increased seed and oil yields in all irrigation treatments. The maximum seed and oil yields were obtained from 75 kg ha-1 ammonium + 75 kg ha-1 potassium sulfates with the averages of 1950 and 643 kg ha-1, respectively. The results of this study suggest that the application of 75 kg ha-1 ammonium + 75 kg ha-1 potassium sulfates can improve the camelina seed and oil yields under full irrigation and late-season drought stress treatments.