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. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija

E. Nádasy-M. Nádasy: 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 Opatija

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

5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija E. Nádasy-M. Nádasy: 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 medium high 2500 > very high

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

5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija E. Nádasy-M. Nádasy: 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

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

Effect of nitrogen fertilization on lettuce varieties Methods  pot experiment in green house  four replications  Ramann brown forest soil  varieties: Kobak, Május királya, 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. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija

Nitrate concentration of different lettuce varieties influenced by N- fertilizer doses N-treatments mg /kg soil mg NO 3 /kg fresh mass kobak május királya great leaks E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers LSD5%:227

Effect of nitrogen and water supply on lettuce Methods  pot experiment in green house  four replications  Ramann brown forest soil  variety: Balaton zöld  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. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija

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

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

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

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. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP Opatija  0, 100, 200, 300 mg N/kg soil as ―ammonium-nitrate ―ammonium nitrate+calcium- carbonate (Pétisó) ―carbamide ―calcium-nitrate (Kalcinol)

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

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 Opatija E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers

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