بررسی اثر کودهای ازته و پتاسیمی بر تحمل به تنش خشکی و خواص کمی و کیفی گندم دیم

In order to study the effect of nitrogen and potassium fertilizers on quality and grain yield of rain fed wheat and evaluation of its on wheat drought stress, experiment were carried out with four levels of nitrogen as(N0, N30, N60 and N90) kg/ha N and four levels of potassium as(K0,K30, K60 and K90) Kg/ha K2O with three replications on rain fed as factorial experiment based on randomized complete block design in two different watering regims, consist of (C1:Rain fed and C2:Supplemental irrigation in requirement phonological stages)at research station of Ghamloo during 2004-2006. Half of nitrogen and potassium fertilizers from urea and potassium chloride resources were used in autumn. Remain of urea and potassium chloride were used in spring before the first rain as side dressing in tillering stage. Seeds were planted from Azar2 variety with density of 150kg/ha. Soil moister content was measured at different phonological stages.Water requirement was calculated based on soil moistur content. Then irrigation was done two stages consist of flowering and grain filling. Leaf samples were collected from flag leaves at spike stage. Then nitrogen and potassium concentration were measured. Wheat was harvested by experimental combine. Then grain yield, straw yield and TWK was determined. Nitrogen and potassium concentration in grain was measured. In order to evaluation of effect of nitrogen and potassium fertilizers on drought stress tolerance and Stress Susceptibility and tolerance indexes such as SSI, STI, K1STI and K2STI and other physiological index was calculated. Results of complete analysis variance of effects of different rates of nitrogen and potassium in two moisture conditions on quality and quantity rain fed wheat showed that the effect of nitrogen fertilizer on grain yield were significant, but these effects on straw yield, nitrogen concentration in flag leaf, grain and seed protein content weren't significant. Effects of different rates of nitrogen fertilizer on TKW were significant at 1% and 5% levels in rain fed and supplemental irrigation conditions respectively. Effects of different rates of potassium fertilizer in two different watering regimes on x Member of Scientific Staff at Soil and Water Research Department of Agricultural and Natural Resources Research Center of Kurdisan Created with Print2PDF. To remove this line, buy a license at: http://www.software602.com/ grain yield, straw yield, and TKW, potassium and nitrogen concentration in flag leaf weren't significantly different. Effects of different rates of potassium fertilizer on nitrogen concentration in seed were significant at 1% level, but in two moisture conditions these effects were not significant on potassium concentration. Effects of nitrogen and potassium fertilizers interaction on seed protein contents were significant at 1% level in rain fed condition, but these effects weren't significant in supplemental irrigation condition. In rain fed condition, comparison of mean of grain yield of N30, N60 and N90 treatments relative check had increased grain yield about 315 ,468 and 593 Kg/ha respectively so that, it was significant at 1% level. In supplemental irrigation condition, comparison of mean of grain yield at N30, N60 and N90 relative check had increased grain yield about 440, 818 and 1018 Kg/ha respectively that it was significant at 1% level. These results also showed that STI, K1STI and K2STI indexes increased by increasing of nitrogen fertilizer in two years, so that by increasing of nitrogen the stress drought tolerance of rain fed wheat was increased. Based on K2STI and K1STI indexes at the first and second year respectively, potassium fertilizer application as alone without nitrogen was increased the stress drought tolerance of rain fed wheat only at rate of 60 kg/ha. Also results show that the effects of potassium fertilizers on the stress drought tolerance of rain fed wheat were concerned with soil moisture condition. As main point, positive effect of potassium application on increasing the stress drought tolerance of rain fed wheat was superior in drought stress condition relative to optimal moisture condition. In the first year treatment of N60K90 treatment was the best fertilizer compound, but in the second year, treatment of N90K60 was the best fertilizer compound. Study of indexes show that fertilizer requirement for potassium was more than nitrogen fertilizer in optimal moisture condition, but fertilizer requirement was higher for nitrogen than potassium fertilizer in drought stress.

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گندم ها ، کود های شیمیایی ، تنش خشکی ، عملکرد زراعی