Department of Soil and Environmental Sciences, College of Agriculture, University of Sargodha, Sargodha, 40100, Pakistan.
Soil Chemistry Section, Ayyub Agriculture Research Institute, Faisalabad, Pakistan.
Environ Sci Pollut Res Int. 2019 Jun;26(17):17438-17449. doi: 10.1007/s11356-019-05141-x. Epub 2019 Apr 24.
Soil textural composition may be important to control arsenic (As) behavior in soil and movement to plant. Two independent parallel experiments comprising of five As levels (0, 50, 100, 150, and 200 mg As kg soil) and three soil textural types (sandy, loamy, and clayey) were designed for determining As fractionation in soils and its consequential effects on growth, yield, and physiological characteristics of sunflower (Helianthus annuus L.). Six As fractions, i.e., NHCl-extractable, NHF-extractable, NaOH-extractable, HSO-extractable, HO-extractable, and HNO-extractable, were determined. On an average, NHCl-extractable As (the most phytoavailable among the extracted fractions) was 48.9, 19.8, and 6.6% of the total As while the bioaccumulation factor for root ranged between 1.9 and 9.5, 1.8 and 4.4, and 0.8 and 2.1 for sandy, loamy, and clayey textured soils, respectively. There was an increase of 8.3, 5.6, and 6.0 times in malondialdehyde with a subsequent reduction in photosynthetic rate by 53.3, 42.7, and 38.0% and achene yield 90.0, 87.1, and 85.5% in sandy, loamy, and clayey textured soils, respectively at 200 mg As kg as compared with the control. Antioxidant enzyme activities were increased with increasing As addition, and maximum activities were found at 150 mg As kg, where catalase activities were 377.7, 341.6, and 292.0%; peroxidase 788.5, 758.6, and 737.0%; and superoxide dismutase 235.7, 191.8, and 177.2% higher in sandy, loamy, and clayey textured soils, respectively as compared with the control. In conclusion, As fractionation was markedly influenced by soil texture, and toxic effects of As on growth, yield and physiological characteristics of sunflower were maximum in sandy followed by loamy and clayey textured soils in descending order.
土壤质地组成可能对控制土壤中砷（As）的行为和向植物的迁移很重要。设计了两个独立的平行实验，包括五个砷水平（0、50、100、150 和 200mg As kg 土壤）和三种土壤质地类型（沙质、壤质和粘质），以确定土壤中砷的形态和其对向日葵生长、产量和生理特性的影响（Helianthus annuus L.）。测定了六种砷形态，即 NHCl 可提取态、NHF 可提取态、NaOH 可提取态、HSO 可提取态、HO 可提取态和 HNO 可提取态。平均而言，NHCl 可提取态砷（提取态中最具植物有效性的）占总砷的 48.9%、19.8%和 6.6%，根的生物积累因子分别为 1.9-9.5、1.8-4.4 和 0.8-2.1，分别为沙质、壤质和粘质土壤。与对照相比，在 200mg As kg 土壤中，丙二醛增加了 8.3、5.6 和 6.0 倍，光合速率分别降低了 53.3%、42.7%和 38.0%，瘦果产量分别降低了 90.0%、87.1%和 85.5%。抗氧化酶活性随着砷的增加而增加，在 150mg As kg 时达到最大值，其中过氧化氢酶活性分别为 377.7、341.6 和 292.0%；过氧化物酶为 788.5、758.6 和 737.0%；超氧化物歧化酶分别为 235.7、191.8 和 177.2%，分别高于沙质、壤质和粘质土壤。总之，砷的形态受土壤质地的显著影响，砷对向日葵生长、产量和生理特性的毒性效应在沙质土壤中最大，其次是壤质土壤，粘质土壤最小。
