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Response of soil exchangeable and crop potassium concentrations to variable fertilizer and cropping regimes in long‐term field experiments on different soil types
Author(s) -
Andersson S.,
Simonsson M.,
Mattsson L.,
Edwards A. C.,
ÖBorn I.
Publication year - 2007
Publication title -
soil use and management
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.709
H-Index - 81
eISSN - 1475-2743
pISSN - 0266-0032
DOI - 10.1111/j.1475-2743.2006.00058.x
Subject(s) - loam , fertilizer , agronomy , soil water , topsoil , arable land , environmental science , crop rotation , manure , soil science , chemistry , crop , ecology , biology , agriculture
Abstract 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 ∼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.