Understanding the sorption process in natural zeolite and bentonite is necessary for effective utilization of these minerals as nutrient adsorbents and on the other side for controlling release of plant nutrients. This research was undertaken to characterize the ability of natural zeolite and bentonite minerals to adsorb and release zinc and manganese. The potentials for sorption of these ions were evaluated by applying the Langmuir and Freundlich equations. The results showed that Langmuir constant [maximum adsorption (b mmol kg-1)] of both Zn and Mn were for bentonite > zeolite While the [binding strength values (k in L.mmol-1)] for zeolite > bentonite      Zn in case of zeolite showed the lowest desorbed percentage particularly at high levels of sorbed Zn. Only, 74.7 % is readily extractable by DTPA after three successive extractions leaving, 25.3 % Zn retained by the mineral. In case of bentonite, 82.26 % of sorbed Zn is readily extractable by DTPA after three successive extractions leaving, 17.74 % Zn retained by the mineral. In case of Mn, 84.63% of Mn sorbed by zeolite is readily extractable by DTPA after three successive extractions leaving, 15.37% Mn retained by the mineral. In case of bentonite, 89.79 % of adsorbed Mn is readily extractable by DTPA after three successive extractions leaving, 10.21 % Mn retained by the mineral.      This finding may reflect clearly the possibility of using natural zeolite and bentonite as a slow release fertilizer for Zn and Mn and on the other hand preventing soil pollution with heavy metals.

Phytoextraction of heavy metal from contaminated soils is promising remediation technology.  In the present study, hyper-accumulator plants, indian mustard (Brassica juncea.( L) czern) and ryegrass (Lolium multiflorum Lam) have been used to remove the excess undesirable concentrations of zinc and copper from contaminated soil. Zinc and copper uptake have been enhanced by adding EDTA to the contaminated soil using two concentrations (2.5 and 7.5 mmol/Kg soil). Accumulation of Zn by the indian mustard shoots and roots under the effect of EDTA recorded 4 to 6 times as adsorbed by the control while less enhancement of Zn uptake was recorded by the ryegrass shoots and roots. On the other hand, Cu accumulation showed significant enhancing by the ryegrass shoot comparing to the indian mustard shoot at the both employed EDTA concentrations. The ryegrass roots gave enhanced Cu uptake at the EDTA conc. 7.5 mmol/Kg soil only while the indian mustard roots recorded an increasing in the Cu-uptake with the two EDTA concentrations

The beneficial effects of boron, zinc and active dry yeast on yield and fruit quality of Zaghloul date palm grown at the Experimental Orchard, Faculty of Agriculture, Assiut University, Egypt was studied during 2011, 2012 and 2013 seasons. The experiment was set up in a complete randomized block design with ten replicates each of one bunch. All treatments were sprayed two times after fruit set and one month later. The obtained results could be summarized as follow: -       Boron, zinc and active dry yeast sprays significantly increased the fruit retention percentage and bunch weight compared to the untreated ones. Yeast application was more effective compared with boron or zinc application. -       Spraying either yeast, boron or zinc at any studied concentration was accompanied with improving fruit quality in terms of significant increase in fruit weight, total soluble solids and sugar contents. No significant differences were detected between spraying with yeast at 250 or 500 ppm, 500 or 1000 ppm zinc, as well as, boron at 1000 or 2000 ppm. Moreover, active dry yeast spraying revealed the highest improvement in palm yield and fruit quality. However, it can be concluded that spraying either boric acid, zinc sulphate or active dry yeast twice after fruit set and one month later increased the palm yield and improved the fruit quality of Zaghloul date palm. Meanwhile, using dry yeast as more effective than both boric acid and zinc sulphate.

Understanding the sorption process in natural zeolite and bentonite is necessary for effective utilization of these minerals as nutrient adsorbents and on the other side for controlling release of plant nutrients. This research was undertaken to characterize the ability of natural zeolite and bentonite minerals to adsorb and release zinc and manganese. The potentials for sorption of these ions were evaluated by applying the Langmuir and Freundlich equations. The results showed that Langmuir constant (maximum adsorption (b mmol kg-1)) of both Zn and Mn were for bentonite zeolite While the [binding strength values (k in L.mmol1 for zeolite bentonite Zn in case of zeolite showed the lowest desorbed percentage particularly at high levels of sorbed Zn. Only, 74.7 % is readily extractable by DTPA after three successive extractions leaving, 25.3 % Zn retained by the mineral. In case of bentonite, 82.26 % of sorbed Zn is readily extractable by DTPA after three successive extractions leaving, 17.74 % Zn retained by the mineral. In case of Mn, 84.63% of Mn sorbed by zeolite is readily extractable by DTPA after three successive extractions leaving, 15.37% Mn retained by the mineral. In case of bentonite, 89.79 % of adsorbed Mn is readily extractable by DTPA after three successive extractions leaving, 10.21 % Mn retained by the mineral. This finding may reflect clearly the possibility of using natural zeolite and bentonite as a slow release fertilizer for Zn and Mn and on the other hand preventing soil pollution with heavy metals.

The interactions between dietary zinc, copper and iron and their effects on antioxidant enzymes activity [superoxide dismutase (SOD), catalase (CAT) and glutathione S-transferase (GST)] were examined. Fifty-four rats weighting approximately between 80-100 grams were divided into nine groups (E1- E9). Each group containing six rats was fed on basal diet with varying amount of Zn (2.5, 35 or 175 mg Zn/kg diet), Cu (1.2, 6.3, or 25 mg Cu/kg diet) and Fe (10, 50 or 230 mg Fe/kg diet). The second group (E2) was fed a diet defi-cient in all studied elements (2.5mg Zn, 1.2mg Cu, and 10mg Fe per 1 kg diet). The results of E2 showed a decrease in SOD and CAT activity and increase GST in plasma erythrocytes and tissues. Moreover, plasma thiobarbituric acid reactive sub-stances (TBARs) and hydrogen peroxide produc-tion in E2 were found to be higher than those in other groups. The high activity of lactic acid de-hydrogenase (LDH) in the plasma indicated that cell membrane damage was occurred. This dam-age was accompanied by elevation of lipid peroxi-dation and in the same time by reduction of SOD and CAT activity. Supplementation of basal diet with the different concentrations of studied miner-als led to improve the activity of antioxidants en-zymes (SOD and CAT) and decrease in TBARs and LDH activity.