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Sammanfattning

Annual potassium (K) balances have been calculated over a 40-year period for five field experiments located on varying parent materials (from loamy sand to clay) in south and central Sweden. Each experiment consisted of a number of K fertilizer regimes and was divided into two crop rotations, mixed arable/livestock (I) and arable only (II). Annual calculations were based on data for K inputs through manure and fertilizer, and outputs in crop removal. Plots receiving no K fertilizer showed negative K balances which ranged from 30 to 65 kg ha(-1) year(-1) in rotation I, compared with 10-26 kg ha(-1) year(-1) for rotation II. On sandy loam and clay soils, the K yield of nil K plots (rotation I) increased significantly with time during the experimental period indicating increasing release of K from soil minerals, uptake from deeper soil horizons and/or depletion of exchangeable soil K (K-ex). Significant depletion of K-ex in the topsoil was only found in the loamy sand indicating a K supply from internal sources in the sandy loam and clay soils. On silty clay and clay soils, a grass/clover ley K concentration of similar to 2% (dry weight) was maintained during the 40-year study period on the nil K plots, but on the sandy loam, loam and loamy sand, herbage concentrations were generally less than 2% K.

Nyckelord

long-term field experiments; potassium fertilizers; exchangeable soil potassium; potassium balance; grass/clover ley potassium concentration

Publicerad i

Soil Use and Management
2007, volym: 23, nummer: 1, sidor: 45949
Utgivare: BLACKWELL PUBLISHING

SLU författare

  • Andersson, Stefan

    • Institutionen för markvetenskap, Sveriges lantbruksuniversitet

  • Mattsson, Lennart

    • Institutionen för markvetenskap, Sveriges lantbruksuniversitet

  • Öborn, Ingrid

    • Institutionen för markvetenskap, Sveriges lantbruksuniversitet

UKÄ forskningsämne

Jordbruksvetenskap

Publikationens identifierare

  • DOI: https://doi.org/10.1111/j.1475-2743.2006.00058.x

Permanent länk till denna sida (URI)

https://res.slu.se/id/publ/15246