The soil's part in integrated production. 4. New findings about reproducibility of analysis results | La part du sol dans la production integree. 4. Nouvelles observations sur la reproductibilite des resultats d'analyses de sol
2007
Neyroud, J.-A.,Station de recherche Agroscope Changins-Waedenswil ACW, Nyon (Switzerland) | Lischer, P. | Zimmermann, A.
During 17 years the stable and variable soil properties of about 800 plots belonging to farms cultivated according to the rules of the swiss integrated production were studied. Repeating the analyses showed that even supposedly stable properties like clay content or cation exchange capacity were strongly reacting to the heterogeneous nature of the soils. An analysis repeated after 5 years safely detects differences of 3-4% clay, 3.0 cmol+/kg CEC, 8% base saturation, 0.4% OM, 0.4 pH unit, 6 P-CO2 Indices, 1.8 mg K-CO2, 4.3 mg Mg-CaCl2, 30 mg P-AAEDTA and 70 mg K- or Mg- AAEDTA. Because of these rather high detection levels and of the uncertainty related to sampling conditions close to practical reality, no definite response can be given so far as to whether the IP improved soil condition. One may conclude that the IP regulations, combined with farmers" professional skills were able to maintain soil fertility at its actual good level. Massively reducing the PK input from commercial fertilizers did not yet result into corresponding decreases in soil tests results.
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