Calcium, magnesium, and potassium uptake by crested wheatgrass grown on calcareous soils
Title:
Calcium, magnesium, and potassium uptake by crested wheatgrass grown on calcareous soils
Author:
Robbins, C. W. Mayland, H. F.
Appeared in:
Communications in soil science and plant analysis
Paging:
Volume 24 (1993) nr. 9-10 pages 915-926
Year:
1993-06
Contents:
Forage intake with potassium/(calcium + magnesium) [K/(Mg + Ca)] values in excess of 2.2 are associated with grass tetany and Mg deficiencies in ruminants. This study was conducted to determine the degree to which forage K and Mg concentrations and K/(Ca + Mg) ratios could be predicted from soil bicarbonate (HCO3) extractable phosphate-phosphorus (PO4-P), and saturation extract Ca, Mg, K, sodium (Na), and nitrate-nitrogen (NO3-N) concentrations. Crested wheatgrass (Agropyron spp) strains and cultivars representing four ploidy levels were grown in the greenhouse on eight calcareous soils with different saturation extract Ca, Mg, K and K/Mg ratios. The plants were harvested three times. Soil solution K/(Ca + Mg) and K/Mg ratios were the only measured soil parameters that showed a consistent correlation with plant K/(Ca + Mg) ratios. Bicarbonate extractable soil P was positively related to plant P and K uptake in the first harvest, but was not related in the second and third harvests nor was soil P related to plant Ca or Mg content. There was a tendency for the higher ploidy level entries to have higher plant K/(Ca + Mg) ratios. It was concluded that soil K/(Ca + Mg) ratios can be used to predict relative forage K/(Ca + Mg) ratios for grasses grown under similar conditions.
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