Praiya Rashki; halime piri; Eisa khammari
Abstract
In this study, the effect of different levels of irrigation water and potassium fertilizer on Roselle was investigated. The experiment was conducted using split plot design with four levels of irrigation water (I1, I2, I3 and I4 equivalent to 40%, 60%, 80%, and 100% crop water requirement) and three ...
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In this study, the effect of different levels of irrigation water and potassium fertilizer on Roselle was investigated. The experiment was conducted using split plot design with four levels of irrigation water (I1, I2, I3 and I4 equivalent to 40%, 60%, 80%, and 100% crop water requirement) and three levels of potassium (K1, K2 and K3 equivalent 50%, 75%, and 100% potassium requirement) as sub-plot. At the end of experiment, quantitative parameters of plant including height, weight and number of capsules, dry yield, and water use efficiency were measured. Also, qualitative parameters including anthocyanin, protein, and carbohydrate content were measured to investigate the effects of water stress and fertilizer on Roselle quality. The results showed that the simple effects of irrigation water and potassium fertilizer were significant (P <0.01) on all measured parameters. The highest yield was obtained from 100% potassium fertilizer treatments and 80% water requirement. The highest water use efficiency was obtained in 60% water requirement plus 100% potassium fertilizer application, but no significant difference was found between 60% and 80% water requirement. The anthocyanin, protein, and carbohydrate contents increased with decreasing irrigation water depth to 60% of plant water requirement and decreasing potassium fertilizer application. However, there was no significant difference between 50% and 75% K fertilizer application. Therefore, due to the water status of the region and the reduction in water resources, application of 80% water requirement reduces water consumption and 75% potassium fertilizer increases quality and mitigates effect of drought stress in Roselle.
halime piri; Abolfazl Bameri
Abstract
In this research, the effect of different levels of irrigation water, nitrogen fertilizer, and cow manure on garlic was investigated. The experiments were carried out in a split-spilt plot design, with four levels of irrigation water depths (40%, 60%, 80% and 100% of the plant water requirement) in the ...
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In this research, the effect of different levels of irrigation water, nitrogen fertilizer, and cow manure on garlic was investigated. The experiments were carried out in a split-spilt plot design, with four levels of irrigation water depths (40%, 60%, 80% and 100% of the plant water requirement) in the main plots, three levels of nitrogen (50, 75 and 100% nitrogen) in the sub- plots, and three levels of manure (25, 32.5 and 50 ton/ha cow manure) in the sub-plots. Nitrogen was applied in two stages and cow manure in one stage before planting. At the end of the experiment, parameters such as plant height, weight, and number of garlic, yield, and irrigation water productivities were measured. The results showed that the effects of irrigation water, nitrogen fertilizer, and manure were significant (p< 1% and <5%) on all parameters. The highest yield was obtained from 100% fertilizer application and 100% water requirement, but no significant effect was observed between treatments of 100 and 80% of water requirement. The highest amount of irrigation water utilization was obtained at irrigation level of 60% and fertilizer level of 100% (1.48 kg/m3/ha). In this regard, there was no significant difference between treatments of 60% and 80% of water requirements. The amount of allicin was reduced by reducing irrigation water and reducing fertilizer use. Increasing nitrogen fertilizer up to 75% of fertilizer requirement, amounting to 150 kg/ha, resulted in increase of allicin, but higher amounts resulted in decrease of allicin content. Therefore, due to shortage of water in the region, irrigation of this crop can be done with 80% of the plant's water requirement, without a significant effect on the yield.
halime piri
Abstract
In order to study the effects of different levels of irrigation, nitrogen fertilizer, and irrigation methods on yield and yield components of onions, a factorial split plot experiment was conducted in a randomized complete block design with three replications for two years at a research farm in ...
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In order to study the effects of different levels of irrigation, nitrogen fertilizer, and irrigation methods on yield and yield components of onions, a factorial split plot experiment was conducted in a randomized complete block design with three replications for two years at a research farm in Zahak, Iran. Fertilizer treatments were included four levels of nitrogen fertilizer of from urea fertilizer (130, 97.5, 65 and 32.5 kg/ha). Onion seedlings were planted in 2014 and 2015 and irrigation was carried out in the form of surface gravity irrigation, surface drip irrigation and subsurface drip irrigation. The highest yield and water productivity were obtained in the subsurface drip irrigation system (28.42 ton/ha and 5.9 kg/m3/ha) and the least in surface irrigation (19 ton/ha and 33.3 kg/m3/ha). Reducing the amount of nitrogen fertilizer to less than plant requirement reduced the yield of bulbs and the efficiency of onions. The highest yield and water productivity were observed in 100% nitrogen application (31.59 ton/ha and 4.75 kg/m3/ha) and the lowest was in 25% nitrogen fertilizer treatment (16.12 ton/ha and 2.67 kg/m3/ha).The effect of irrigation water on the yield of onion tubers and its efficiency showed that decreasing the depth of irrigation water to values lower than the water requirement of the plant decreases yield and efficiency, but, no significant effect was observed between treatments 100% and 75% of the plant water requirement. Therefore, according to the results, due to the lack of water in the region, irrigation of this plant can be done with 75% of the plant water requirement, without a significant effect on the yield. Also, due to the high production potential in subsurface drip irrigation and reduction of evapotranspiration, this irrigation method could be used for onions in the region. The best treatment for nitrogen fertilizer use is the 100% nitrogen fertilizer requirement, especially in water tension. Considering the contamination of subsurface waters due to the excessive use of nitrogen fertilizers and the prevention of nitrate accumulation in the bulbs, it seems that using drip irrigation improves nitrogen fertilizer management.