title: Testing the ability of plants to access potassium from framework silicate minerals.
abstract: The availability of K, essential for plant growth, from syenite (a silicate rock in which potassium feldspar is the dominant mineral; >90wt%), and phlogopite mica has been demonstrated using carefully designed plant growth pot experiments in which the only added source of K was the mineral of interest, with no loss of nutrients through drainage. Using pure quartz sand as a soil, both growth (increase in diameter) of leek plants and K-content of the plant material showed a dose-dependent positive response to the application (114-43000mgK/pot) of milled syenite with increases in plant diameter of 0.5-0.7mm/week, increasing with application rate. Phlogopite mica (114-6000mgK/pot) supported the highest observed increase in diameter (approx. 1mm/week) and plant K-content, both similar to that observed for a positive control (KCl). These experiments demonstrate that plants can obtain K for growth from milled syenite, in which feldspar is the dominant K-bearing mineral, and confirm previous observations that micas can be an effective source of K.
authors.affiliation: School of Civil Engineering & Geosciences, Newcastle University, NE1 7RU, Newcastle upon Tyne, UK. Electronic address: David.Manning@newcastle.ac.uk.
authors.forename: David A C
authors.initials: DAC
authors.lastname: Manning
authors.affiliation: School of Civil Engineering & Geosciences, Newcastle University, NE1 7RU, Newcastle upon Tyne, UK.
authors.forename: Joana
authors.initials: J
authors.lastname: Baptista
authors.affiliation: University Claude Bernard Lyon 1, 43 Boulevard du 11 Novembre 1918, 69100 Villeurbanne, France.
authors.forename: Mallely
authors.initials: M
authors.lastname: Sanchez Limon
authors.affiliation: School of Agriculture, Food and Rural Development, Newcastle University, NE1 7RU, Newcastle upon Tyne, UK.
authors.forename: Kirsten
authors.initials: K
authors.lastname: Brandt
keywords: Feldspar; Fertiliser; Mica; Mineral; Potassium; Silicate; Soil