Soil boron and selenium removal by three plant species

Abstract

High concentrations of boron (B) and selenium (Se) naturally found in the environment are detrimental to sustainable agriculture in the western USA. Greenhouse pot experiments were conducted to study B and Se uptake in three different plant species; Brassica juncea (L.) Czern (wild brown mustard), Festuca arundinacea Schreb. L. (tall fescue), and Brassica napus (canola) were grown in soil containing naturally occurring concentrations of 3.00 mg extractable B kg-1 and 1.17 mg total Se kg-1 soil. During the growing season, four intermediate harvests were performed on wild mustard and tall fescue. Final harvest I consisted of harvesting wild mustard, canola, and clipping tall fescue. Final harvest II consisted of harvesting wild mustard, which had been planted in soil in which wild mustard was previously grown, and harvesting previously clipped tall fescue. The greatest total amount of above ground biomass and below surface biomass was produced by tall fescue. Plants were separated into shoots and roots, weighed, and plant tissues were analyzed for total B and Se. The highest concentrations of tissue B were recovered in shoots of wild mustard and canola at final harvest I, while roots from tall rescue contained the highest concentrations of B irrespective of the harvest. Tissue Se concentrations were similar in all plants species. Soils were analyzed for residual B and Se. Extractable soil B concentrations at harvest times were lowered no less than 32% and total Se no less than 24% for all three species. The planting of wild mustard, canola, or tall fescue can reduce water-extractable B and total Se in the soil.

Boron accumulation in Puccinellia frigida, an extremely tolerant and promising species for boron phytoremediation

“…Aydın and Çakır, 2009;Bañuelos et al, 1993aBañuelos et al, , 1993bDel-Campo Marín and Oron, 2007;Santos et al, 2010;Tassi et al, 2011). Bañuelos et al (1993a) found that Indian mustard (Brassica juncea), tall fescue (Festuca arundinacea), bird's-foot trefoil (Lotus corniculatus), and kenaf (Hibiscus cannibinus) reduced extractable soil boron by 52% in field experiments.…”

“…The most common treatment practice is leaching (Leyshon and Jame, 1993), but this presents several limitations: (1) large volumes of water are required (Bingham et al, 1972), restricting its application in arid and semiarid regions; (2) removal is often incomplete, i.e., only the soluble fraction is removed, which leaves the sorbed fraction that can recharge the soil solution later (Peryea et al, 1985); and (3) soils must have good drainage capacity (Nable et al, 1997). In addition, the collection of the boron-enriched leachate is necessary to prevent contamination of adjacent sites (Bañuelos et al, 1993b). Another treatment method is to replace the surface soil with soil that has low boron levels; however, this treatment is expensive and the boron from subsurface layers can migrate and recharge the overlying non-contaminated soil (Nable et al, 1997).…”

Metal Ions and Plant Nutrition

“…Greenhouse pot experiments were conducted to study B uptake by different plant species, Brassica juncea (L.) Czern (wild brown mustard), Festuca arundinacea Schreb. L. (tall fescue), and Brassica napus (canola) (Banuelos et al, 1993). Results showed that the greatest total amount of above ground biomass and below surface biomass was produced by tall fescue and the highest concentrations of tissue B were from roots of tall fescue.…”

“…Generally, Se content in plants increases with the level of Se available and decreases with the sulphur supply. Se concentrations in plant tissues were found to be similar in three different plant species: Brassica juncea (L.) Czern (wild brown mustard), Festuca arundinacea Schreb L. (tall fescue) and Brassica napus (canola) when these were grown in soil containing naturally occurring concentrations of 1.77 mg total Se kg-' in greenhouse pot experiments (Banuelos et al, 1993).…”

Phytoremediation of Contaminated Water and Soil

“…Selenium phytoremediation as phytoextraction (17) and "phytovolatilization" (18) have both been explored. More recently, transgenic plants have been shown to reduce Hg from the more hazardous ionic and methylated forms to Hg(0), which is then volatilized (19).…”