Nitrogen fertilization

2. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 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 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

3. 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 2006. Opatija

4. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija Classification of vegetables on the basis of accumulated nitrate (Terbe et al., 1986)

5. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija Classification of the plants according to the nitrate content NO3 mg/kg fresh massNitrate content of the plant < 500 low 500-1500 medium 1500-2500 high 2500 > very high

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

7. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija 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

8. . Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 6400 5600 NH4NO3 Effect of N-fertilizers on nitrate content of pea leaves 4800 (NH4)2SO4 4000 mg/kg fresh mass Ca(NO3)2 3200 2400 1600 3 NO 800 0 0 40 80 160 320 640 N-treatments (mg N/kg soil) 6400 In blossom 5600 NH4NO3 4800 (NH4)2SO4 4000 6400 mg/kg fresh mass Ca(NO3)2 3200 5600 NH4NO3 2400 4800 (NH4)2SO4 1600 4000 3 mg/kg fresh mass NO 800 Ca(NO3)2 3200 0 2400 0 40 80 160 320 640 1600 3 N-treatments (mg N/kg soil) NO 800 At 4-6 leaf stage 0 0 40 80 160 320 640 N-treatments (mg N/kg soil) Atripening 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

9. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers Effect of nitrogen fertilization on lettuce varietiesMethods • 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 NH4NO3 • irrigation by weigh to 70% of MWHC • leaf samples were collected at 8 week age 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

10. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija Nitrate concentration of different lettuce varieties influenced by N- fertilizer doses 6000 5000 kobak LSD5%:227 május királya 4000 /kg fresh mass great leaks 3000 3 2000 mg NO 1000 0 0 100 400 800 N-treatments mg /kg soil

11. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers Effect of nitrogen and water supply on lettuceMethods • pot experiment in green house • four replications • Ramann brown forest soil • variety: Balaton zöld • 0, 100, 200, 300, 400 mg N/kg soil as NH4NO3 • irrigation by weigh to 40, 60, 80 % of MWHC • leaf samples were collected at 6 week age 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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

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

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

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

16. E. Nádasy-M. Nádasy: Some harmful or useful environmental effect of nitrogen fertilizers Mortality of cockchafer grub effected by Steinernema glaseri influenced by nitrogen fertilizers LSD5%:11,5 5th ALPS-ADRIA SCIENTIFIC WORKSHOP 2006. Opatija

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

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