Buğdayda Kadmiyumun Toksiklik Sınırının Belirlenmesi ve Bazı Ekstraksiyon Yöntemlerinin Karşılaştırılması

OZETBu arastirmada, agir metal ve potansiyel toksik bir element olan kadmiyumun(Cd) bitkiye toksik oldugu seviyeleri toprakta ve bitkide belirlemeye calisilmistir. Bu amacla ekim oncesi topraga 0, 5, 15, 30 ve 45 mg/kg seviyelerinde Cd uygulamasi yapilmistir. Deneme killi ve killi tinli bunyeli iki farkli bunyeli toprakta ve sera kosullarinda yurutulmustur. Elde edilen sonuclara gore, topraga uygulanan kadmiyum bugdaya toksik olmus ve topraga uygulanan kadmiyum  miktari arttikca bugdayin kuru agirligi azalmistir. En yuksek bugday kuru agirligi kontrol konusundan alinirken, en dusuk ise 45 ppm (mg/kg) Cd uygulamasindan elde edilmistir. Artan duzeylerde uygulama ile bitki verimi azalirken, kadmiyumun bitki bunyesindeki miktari ise artmistir. Bugdayin ust aksamindaki Cd miktari ile kuru agirlik arasindaki iliski de incelenmis ve bitkiye toksik olan Cd duzeyi belirlenmistir. Bu calismada ayrica topraga uygulanan kadmiyumun topraktan geri ekstraksiyonu ile Cd belirlemesi de yapilmis ve bazi ekstraksiyon yontemleri karsilastirilmistir. Kadmiyum uygulamasi yapilan topraklardan DTPA; EDDHA, Amonyum Asetat (pH4 ve pH7), Nitrik Asit ve EDTA yontemleri ile ekstraksiyonlar yapilarak toprakta Cd belirlenmistir. Kadmiyumun topraktan ekstraksiyonunda bu yontemlerden bazilari zayif kalmis, yani topraktan dusuk miktarda Cd ekstrakte etmistir. Bazi yontemler ise topraga ilave edilen miktari geri verecek seviyede etkili bulunmustur. DETERMINATION OF TOXICITY LIMITS OF CADMIUM FOR WHEAT AND COMPARISON OF SOME EXTRACTION METHODSABSTRACTStudy aims at determining plant-toxicity levels of Cd which is potentially a toxic heavy metal, in soil and plant. For this purpose 0, 5, 15, 30 and 45 ppm Cd were applied to soil before sowing. Experiments were conducted in greenhouse condition, and the experimental materials were clay loam and clay-textured soils. Results showed that soil applied Cd doses have toxic impact on wheat. When the quantity of soil applied Cd was increased, dry weight of wheat diminished substantially. Highest yield was obtained in control treatments, lowest yield was observed in soil applied Cd of 45 ppm. Increased application of Cd resulted in decline in yield, whereas concentration in plant structure showed in increase. The relation between Cd concentration in the upper parts of the plant and dry weight was examined, and toxic concentration was recorded. Additionally, Cd assessment was performed by using reverse extraction of Cd from soil as well, and some extraction methods were compared. Compared extraction methods include; DTPA, EDDHA, EDTA, Ammonium Acetate (pH7and pH 4.8) and Nitric acid. While few methods can found to be insufficient in extracted Cd from soil, hence, low quantity of Cd was extracted, some others was observed to be efficient as tor ender the quantity that was added to soil.