Van Mantgem P J, Wu L, Banuelos G S
Department of Environmental Horticulture, University of California, Davis, California, 95616, USA.
Ecotoxicol Environ Saf. 1996 Aug;34(3):228-38. doi: 10.1006/eesa.1996.0068.
A forage plant, tall fescue (Festuca arundinacea), and a selected field legume species, sour clover (Melilotus indica), were examined for their selenium (Se) bioextraction abilities in Se-laden soils under minimal management conditions. Natural vegetations in a 2-acre plot adjacent to the forage plots were also studied for Se accumulation comparisons. During the dry season, in the fall of 1994, the field plots were either irrigated weekly or without irrigation. No fertilization and weed control were applied. The plants were harvested in May 1995. There were considerable differences in the ability of Se uptake between the forage and the legume species and among the naturally established plant species; the amount of Se accumulated per land area was largely dependent on their respective biomass production. Comparing Se concentration between preplant and postharvest, there was a detectable reduction in the soil selenate, selenite, and water-extractable organic Se in the tall fescue and melilotus plots. The field irrigation provided more favorable conditions for bioextractions and dissipation of Se by the plants. However, the available soil Se only accounts for less than 10% of the total soil Se and no detectable reduction of total soil Se was found. This may be due to the large inventory and variation of Se concentrations in the field soils and therefore obscured the detectable differences. For practical considerations, the forage plants can be repeatedly harvested and used for rangelands of Se deficiency currently seen in some northern California counties.
对一种饲用植物高羊茅（Festuca arundinacea）和一种选定的田间豆科植物印度草木犀（Melilotus indica）在最少管理条件下对富硒土壤中硒的生物提取能力进行了研究。还对饲用植物地块相邻的一块2英亩土地上的天然植被进行了硒积累情况的比较研究。在1994年秋季旱季期间，田间地块每周进行灌溉或不进行灌溉。未施肥和除草。这些植物于1995年5月收获。饲用植物和豆科植物之间以及天然生长的植物物种之间在硒吸收能力上存在显著差异；每单位土地面积积累的硒量在很大程度上取决于它们各自的生物量产量。比较种植前和收获后土壤中的硒浓度，高羊茅和草木犀地块中的土壤硒酸盐、亚硒酸盐和水可提取有机硒有可检测到的减少。田间灌溉为植物生物提取和硒的消散提供了更有利的条件。然而，土壤中可利用的硒仅占土壤总硒的不到10%，且未发现土壤总硒有可检测到的减少。这可能是由于田间土壤中硒浓度的存量大且变化大，因此掩盖了可检测到的差异。出于实际考虑，这些饲用植物可以反复收获并用于目前在加利福尼亚州北部一些县出现的缺硒牧场。
