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Nitrogen fertilization Essential to the optimal nutrient supply of the plants. Useful effects: more crop better quality Harmful effects: leaching to the groundwater or surface water get into the food chain as nitrate direct or indirect effect on animals living in the soil : changing pH and salinity of the soil, influences feeding of the pests E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers Transformation of nitrate in the plants and in the human organizm 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers Classification of vegetables on the basis of accumulated nitrate (Terbe et al., 1986)

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5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers Classification of the plants according to the nitrate content NO 3 mg/kg fresh mass Nitrate content of the plant < 500 low 500-1500medium 1500-2500high 2500 > very high

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5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers Maximum level of nitrate in vegetables in EU

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5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers Determinants of nitrate accumulation of plants Genetical factors:Environmental factors: - species and varieties of plant - characteristics of soil - stadium of growth - period and intensity of light - plant part - temperature - water supply Cultivation factors: Food-industrial processes -plant nutrition, mainly N -plant protection, pesticides -time of sowing and harvesting, growing period

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Effect of N-fertilizers on nitrate content of pea leaves At ripening In blossom At 4-6 leaf stage 0 800 1600 2400 3200 4000 4800 5600 6400 04080160320640 N-treatments (mg N/kg soil) NO 3 mg/kg fresh mass NH4NO3 (NH4)2SO4 Ca(NO3)2 0 800 1600 2400 3200 4000 4800 5600 6400 04080160320640 N-treatments (mg N/kg soil) NO 3 mg/kg fresh mass NH4NO3 (NH4)2SO4 Ca(NO3)2 0 800 1600 2400 3200 4000 4800 5600 6400 04080160320640 N-treatments (mg N/kg soil) NO 3 mg/kg fresh mass NH4NO3 (NH4)2SO4 Ca(NO3)2. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Effect of nitrogen fertilization on lettuce varieties Methods pot experiment in green house four replications Ramann brown forest soil varieties: Kobak, Mjus kirlya, Great lakes 0, 100, 400, 800 mg N/kg soil as NH 4 NO 3 irrigation by weigh to 70% of MWHC leaf samples were collected at 8 week age E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Nitrate concentration of different lettuce varieties influenced by N- fertilizer doses 0 1000 2000 3000 4000 5000 6000 0100400800 N-treatments mg /kg soil mg NO 3 /kg fresh mass kobak mjus kirlya great leaks E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers LSD5%:227

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Effect of nitrogen and water supply on lettuce Methods pot experiment in green house four replications Ramann brown forest soil variety: Balaton zld 0, 100, 200, 300, 400 mg N/kg soil as NH 4 NO 3 irrigation by weigh to 40, 60, 80 % of MWHC leaf samples were collected at 6 week age E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Effect of nitrogen and water supply on fresh mass of lettuce E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Effect of nitrogen and water supply on nitrogen concentration of lettuce E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Effect of N-fertilization and water supply on nitrate content of lettuce E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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Interaction between N-fertilization, cockchafer grub and entomophatogenic nematodes Methods Pot experiment in laboratory, 14 day period 4 cockchafer grub+1500 pieces of Steinernema glaseri/ pot E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija 0, 100, 200, 300 mg N/kg soil as ammonium-nitrate ammonium nitrate+calcium- carbonate (Ptis) carbamide calcium-nitrate (Kalcinol)

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Mortality of cockchafer grub effected by Steinernema glaseri influenced by nitrogen fertilizers E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija LSD 5% :11,5

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Conclusions We must keep away from overdosage of N- fertilizer in lettuce growing. It was established that we can decrease nitrate content of lettuce with optimal water supply. We must prefer genetically low nitrate storable varieties. N-fertilizers can effect on pests and nematodes living in the soil. N-fertilizers had not any negative effect on cockchafer grubs. Nematodes were more sensitive to fertilization. 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers

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Thank you for your attention! E. Ndasy-M. Ndasy: Some harmful or useful environmental effect of nitrogen fertilizers THANK YOU FOR YOUR ATTENTION! 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija