Presentation witzenhausen nov2009

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Quality of cattle manure

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Presentation witzenhausen nov2009

  1. 1. Cattle diet composition and fertilizer value of excreta Egbert A. Lantinga Group of Biological Farming Systems Department of Plant Sciences [email_address]
  2. 2. <ul><li>Cattle dung </li></ul><ul><li>Cattle slurry </li></ul><ul><li>Phytotoxicity: lab vs. field experiments </li></ul><ul><li>Long(er)-term effects </li></ul>Outline
  3. 3. <ul><li>Influence of feeding strategy on growth and rejection </li></ul><ul><li>of herbage around dung pats and their decomposition </li></ul><ul><li>Continously grazed pasture </li></ul><ul><li>Experimental period: 6 weeks </li></ul><ul><li>Artificial dung pats (2.5 kg fresh dung; Ø 31 cm; height 9 cm) </li></ul><ul><li>Dung from 4 diverging cattle farms </li></ul>(Bosker, Hoekstra & Lantinga, 2002) CATTLE DUNG
  4. 6. Grass cages 4 grass cages
  5. 7. Results: Index factors (column mean=100) Index factors Cage: undisturbed DM yield ( Ø 64 cm) R1: DM yield within grazed dung area R2: DM yield around grazed dung area PDD: % dung disappeared (+ straw)
  6. 10. Cattle slurry <ul><li>Low C/N-ratio + high N min -content: </li></ul><ul><li>- phytotoxic effects on herbage? (ammonia, salts, heavy metals, biogenic amines, phenolic compounds) </li></ul><ul><li>- herbage rejection by grazing cattle? (volatile fatty acids, ammonia and volatile amines) </li></ul><ul><li>Experiments: </li></ul><ul><li>- bio-assay (germination of cress seeds) </li></ul><ul><li>- field trial (herbage N recovery and </li></ul><ul><li>grazing behaviour: change in sward height in manured plots) </li></ul>(Reijs, Meijer, Bakker and Lantinga, 2003)
  7. 11. Roughages in cattle diets <ul><li>Grazed Grass Maize Wheat Wheat </li></ul><ul><li>grass silage silage silage straw </li></ul><ul><li>APMlac + - - + + </li></ul><ul><li>OSK + - - - - </li></ul><ul><li>APMdry - + - + + </li></ul><ul><li>MAR + + + - - </li></ul>
  8. 12. Bio-assay: Germination index (ammonia)
  9. 13. Bio-assay: Germination index (salinity)
  10. 14. Bio-assay: Germination index (copper)
  11. 15. Bio-assay: Germination index(phenol)
  12. 16. Bio-assay: Germination index <ul><li>Phytotoxic effect: MAR > APMlac > OSK > APMdry </li></ul><ul><li>Slurry C/N ratio: 10 9 14 16 </li></ul><ul><li>Germination inhibiting effects: </li></ul><ul><li>1. NH 3 /NH 4 + </li></ul><ul><li>2. salinity (electronic conductivity) </li></ul><ul><li>3. Cu (weak) </li></ul><ul><li>4. Phenol (no) </li></ul>
  13. 17. Grazing behaviour: Change in Herbage Height (CHH; cm) after one week (no fertilizer effects!) <ul><li>Ranking order </li></ul><ul><li>0 N > APMdry > OSK > APMlac > MAR </li></ul><ul><li>-1.4 -0.4 -0.2 -0.1 +0.6 </li></ul><ul><li>Positively and significantly correlated with slurry NH 3 /NH 4 + -N content (R 2 = 0.98) </li></ul>
  14. 18. Fertilizer value (growth period 5 weeks) straw in diets -> 0 N
  15. 19. Bio-assay phytotoxicity and field slurry quality <ul><li>Ranking order: the slurry with the greatest phytotoxicity (lab) showed highest herbage yield after five weeks (field)! </li></ul><ul><li>Buffering capacity soil </li></ul><ul><li>Sensitivity differences between roots of cress seedlings and established grass root systems </li></ul><ul><li>Straw (C/N-ratio ~ 80): temporary N-immobilization </li></ul>
  16. 20. Longer term fertilizer effects: one year <ul><li>Field experiment: effects different diets on N utilization from cattle slurry </li></ul><ul><li>MFE (mineral fertilizer equivalent; %) </li></ul><ul><li>= 100 * EFR / total slurry-N </li></ul><ul><li>EFR = equivalent fertilizer N response (i.e. amount of mineral fertilizer N needed to attain the same N yield as with slurry) </li></ul><ul><li>Two grassland fields on sand: NEW and OLD (age 5 vs ~50 years); OLD field higher groundwater level -> higher denitrification losses (wet spring) </li></ul>(Reijs, Sonneveld, S Ø rensen, Schils, Groot and Lantinga, 2007)
  17. 21. NEW OLD O O O O O: 50% straw
  18. 22. Long-term soil quality effects (200 years) Initial and equilibrium topsoil characteristics after long-term applications (180 kg N ha -1 yr -1 ) of two extreme slurries (C:N total 14.5 vs. 26.3) Model: FarmDances (J.C.J. Groot, WUR)
  19. 23. Long-term soil quality effects (200 years)
  20. 24. <ul><li>Inclusion of chopped straw in cattle diets (~5% on DM basis): herbage rejection grazing cattle ↓; dung decomposition rate ↑; temporary immobilization slurry N min -> short-term (one year) N fertilizing effect ~ 0 </li></ul><ul><li>Lab bio-assays with cress seeds are not realistic to assess phytotoxity of slurry for the field situation </li></ul><ul><li>Compensation of reduced first year’s N availability of slurry with high C:N total ratio’s will take some decades (gradually increasing soil N delivery due to N accumulation) </li></ul>CONCLUSIONS

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