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| Keller, Martina; Oberson, Astrid; Annaheim, Kathrin E.; Tamburini, Federica; Mäder, Paul; Mayer, Jochen; Frossard, Emmanuel; Bünemann, Else K.. |
| Lower P-input levels in organic than conventional farming can decrease soil total and available P, which can potentially be resupplied from soil organic P. We studied the effect of 30 y of conventional and organic farming on soil P forms, focussing especially on organic P. Soil samples (0–20 cm) were taken in a field experiment with a nonfertilized control, two organic systems receiving P inputs as animal manure, and two conventional systems receiving only mineral P or mineral P and manure. Soils were analyzed for total, inorganic, organic, and microbial P, by sequential P fractionation and by enzyme additions to alkaline soil extracts. Samples taken prior to starting the experiment were also analyzed. Average annual P balances ranged from –20 to +5 kg... |
| Tipo: Journal paper |
Palavras-chave: Soil quality; Crop husbandry. |
| Ano: 2012 |
URL: http://orgprints.org/21783/1/keller-etal-2012-JPlantNutrSoilSci-Vol175-p385-393.pdf |
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