Catalogo Articoli (Spogli Riviste)


Potassium content in soil, uptake in plants and the potassium balance in three European long-term field experiments
Blake, L; Mercik, S; Koerschens, M; Goulding, KWT; Stempen, S; Weigel, A; Poulton, PR; Powlson, DS;
ICAR Rothamsted, Dept Soil Sci, Harpenden AL5 2JQ, Herts, England ICAR Rothamsted Harpenden Herts England AL5 2JQ n AL5 2JQ, Herts, England Agr Univ Warsaw, Dept Agr Chem, Warsaw, Poland Agr Univ Warsaw Warsaw Poland niv Warsaw, Dept Agr Chem, Warsaw, Poland Environm Res Ctr, Dept Soil Sci, Bad Lauchstaedt, Germany Environm Res Ctr Bad Lauchstaedt Germany Sci, Bad Lauchstaedt, Germany
Titolo Testata:
fascicolo: 1-2, volume: 216, anno: 1999,
pagine: 1 - 14
fertilizer; long-term experiments; nutrient uptake; potassium balance; potassium dynamics; soil potassium;
Tipo documento:
Settore Disciplinare:
Agriculture,Biology & Environmental Sciences
Indirizzi per estratti:
Indirizzo: Blake, L ICAR Rothamsted, Dept Soil Sci, Harpenden AL5 2JQ, Herts, EnglandICAR Rothamsted Harpenden Herts England AL5 2JQ , Herts, England
L. Blake et al., "Potassium content in soil, uptake in plants and the potassium balance in three European long-term field experiments", PLANT SOIL, 216(1-2), 1999, pp. 1-14


This study quantitatively assesses the fate of K derived from mineral fertilizers and organic manures and the effective K balance in three long-term field experiments at Rothamsted (UK), Bad Lauchstaedt (Germany) and Skierniewice (Poland). Plant availability, uptake and the overall utilization of Kover the last 30 years (1965-1996) are discussed and related to soil K Availability Indices determined by the standard methods used in each of the three countries. In addition, to provide a standard comparison of the three sites, Exchangeable K (1 M NH4OAc) and Non-exchangeable K (K extracted by boiling with 1 M HNO3) were measured on one recent (1995) set of soil samples. Plant availability and utilization of K was partly related to clay content, but more closely to the cation exchange surfaces associated with both mineral and organic constituents and also, at Rothamsted, to the capacity of clay minerals to fix K. The recovery rate of K from mineral fertilizer by crops did not exceed 62%. Fertilizers were least effective in the most strongly K fixing soil at Rothamsted (44% maximum) and most effective in the soil with the highest cation exchange capacity (CEC) at Bad Lauchstaedt (62%),where the greater quantity of exchange sites appear to be associated with humic material. Recoveries of K from farmyard manure (FYM) varied from 22-117% (values of >100% indicating subsoil uptake or the release of reserves). Deficiencies of N, P and Mg in some treatments decreased the effectivenessof applied K and may have caused increased leaching of K from the plough layer. FYM was generally more effective than mineral fertilizer where mineral N and P were not applied because these nutrients were effectively supplied in the manure. But the effectiveness of mineral K fertilizer decreased when applied in combination with FYM because FYM was the preferred source of K. Where FYM application increased the CEC of soils, this also improved K utilization but only where K was not extensively leached or fixed.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 22/09/20 alle ore 13:49:25