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Title: Radium-226 and calcium uptake by crops grown in mixtures of sand and cay tailings from phosphate mining

Journal Article · · Journal of Environmental Quality
 [1];  [2]; ;  [3]
  1. Univ. of Hawaii, Hilo, HI (United States)
  2. Univ. of Florida, Gainesville, FL (United States)
  3. Bromwell & Carrier, Lakeland, FL (United States)

Radium-226 is a naturally occurring radionuclide found in reclaimed clay and sand tailing from phosphate mining. Field studies were conducted to investigate the effects of sand/clay ratio (SCR), Ca supplement and organic amendments on the {sup 226}Ra concentration in turnip, banana pepper, cabbage, yellow squash, mustard, and alfalfa. For vegetables, treatment effects included SCR (2:1, 4:1, 6:1, and 8:1), phosphogypsum (PG) 0,22, and 134 Mg ha{sup {minus}1}, and peat 0,100, and 200 Mg ha{sup {minus}1}. For alfalfa grown in a 1:1 SCR mixture, treatments included organic amendments (control, peat, sewage slude, sawdust, composted sewage sludge, composted garbage and humate) applied at 44.8 Mg ha{sup {minus}1} (2.2 Mg ha{sup {minus}1} for humate). Plant {sup 226}Ra concentration tended to be higher in the 4:1 than in the 2:1 SCR mix but this depended on the crop an d the season. Organic amendments and PG had no effect (p<0.05) on the {sup 226}Ra concentration in vegetables and alfalfa. Mean {sup 226}Ra concentration in plant tissues ranged from 3.4 Bq kg{sup {minus}1} in banana pepper fruit to 31.1 Bq kg{sup {minus}1}. A quadratic relationship based on 631 observations was observed between {sup 226}Ra and Ca concentration in plant tissues. The {sup 226}Ra/Ca ratio in plant tissues ranged from 0.85 to 2.13 kBq {sup 226}Ra kg{sup {minus}1} Ca and decreased with increasing plant {sup 226}Ra. Results indicated that wide differences in plant {sup 226}Ca concentration were related more to differences in plant Ca levels than to soil factors. 21 refs., 1 fig., 6 tabs.

Sponsoring Organization:
USDOE
OSTI ID:
263099
Report Number(s):
CONF-9101175-; ISSN 0047-2425; TRN: 96:002035-0006
Journal Information:
Journal of Environmental Quality, Vol. 23, Issue 4; Conference: National symposium on naturally occurring radionuclides in agricultural products, Orlando, FL (United States), 24-25 Jan 1991; Other Information: PBD: Jul-Aug 1994
Country of Publication:
United States
Language:
English