Turan Veysel
Department of Soil Science and Plant Nutrition, Faculty of Agriculture, Bingöl University, Bingöl, Turkey.
Int J Phytoremediation. 2022;24(2):166-176. doi: 10.1080/15226514.2021.1929826. Epub 2021 May 30.
The presence of Ni above the permissible limit in agriculture soils poses negative effects on soil health, crop quality, and crop productivity. Surprisingly, the usage of various organic and inorganic amendments can reduce Ni mobility in the soil and its distribution in the crops. A pot experiment was conducted to elucidate the effects of olive pulp biochar (BR), calcite (CAL), and wheat straw (WS), as sole amendments and their mixtures of 50:50 ratio, added to Ni polluted soil on Ni mobility in the soil, Ni immobilization index (Ni - IMi), soil enzymatic activities, Ni distribution in parts of chili plant, Ni translocation factor and bioaccumulation factor in fruit, plant growth parameters and oxidative stress encountered by the plants. Outcomes of this pot experiment revealed that amendments raised soil pH, improved soil enzymatic activities, values of Ni - IMi, while significantly reduced bioavailable Ni fraction in the post-harvest soil. However, the highest activities of acid phosphatase, urease, catalase, and dehydrogenase by 50, 70, 239, and 111%, respectively, improvement in Ni - IMi up to 60% while 60% reduction in the bioavailable Ni fraction was observed in BR + CAL treatment, compared to control was noted. Among all amendments, the top most reduction in Ni concentrations in shoots, roots, fruit, Translocation Factor (TF), and Bioaccumulation Factor (BAF) values of fruit by 72%, 36%, 86%, 72%, and 86%, in BR + CAL treatment, compared to control. Moreover, the plants growing on BR + CAL amended Ni contaminated soil showed the topmost improvement in plant phonological parameters while encountered the least oxidative stress. Such findings refer to the prospective usage of BR + CAL at 50:50 ratio than BR, CAL, WS alone, and BR + WS as well as WS + CAL for reducing Ni mobility in the soil, improving Ni - IMi, soil enzymatic activities, plant phonological and oxidative stress while reducing Ni distribution in plant parts. In this experiment, it was hypothesized that amending Ni polluted soil with olive pulp biochar (BR), CAL, and WS as alone soil amendments and their combinations at 50:50 ratios can reduce Ni bioavailability in soil, Ni distribution in chili plant and oxidative stress encountered by the plants. Moreover, these amendments may improve, soil enzymatic activities, Ni immobilization index, plant phenological traits. Therefore, it was aimed to undertake useful scientific planning and research, to restore and rehabilitate the dwellings, biological resources and to minimize the sufferings of the peoples in nutrient-poor Ni contaminated soils, by improving soil health and chili productivity.
农业土壤中镍含量超过允许限度会对土壤健康、作物品质和作物生产力产生负面影响。令人惊讶的是，使用各种有机和无机改良剂可以降低镍在土壤中的迁移性及其在作物中的分布。进行了一项盆栽试验，以阐明橄榄果肉生物炭（BR）、方解石（CAL）和小麦秸秆（WS）作为单一改良剂及其50:50比例的混合物添加到镍污染土壤中对土壤中镍迁移性、镍固定指数（Ni-IMi）、土壤酶活性、辣椒植株各部位镍分布、果实中镍转运因子和生物累积因子、植物生长参数以及植物所遭遇的氧化应激的影响。该盆栽试验结果表明，改良剂提高了土壤pH值，改善了土壤酶活性和Ni-IMi值，同时显著降低了收获后土壤中生物可利用镍的含量。然而，与对照相比，BR + CAL处理中酸性磷酸酶、脲酶、过氧化氢酶和脱氢酶的活性分别最高提高了50%、70%、239%和111%，Ni-IMi提高了60%，而生物可利用镍含量降低了60%。在所有改良剂中，与对照相比，BR + CAL处理中地上部、根部、果实中镍浓度、转运因子（TF）和果实生物累积因子（BAF）值分别降低了72%、36%、86%、72%和86%。此外，生长在BR + CAL改良的镍污染土壤上的植株在植物物候参数方面改善最为显著，同时遭遇的氧化应激最小。这些发现表明，50:50比例的BR + CAL比单独的BR、CAL、WS以及BR + WS和WS + CAL在降低土壤中镍迁移性、提高Ni-IMi、土壤酶活性、植物物候和氧化应激以及减少植物各部位镍分布方面更具前景。在本试验中，假设用橄榄果肉生物炭（BR）、CAL和WS作为单独的土壤改良剂及其50:50比例的组合来改良镍污染土壤，可以降低土壤中镍的生物有效性、减少镍在辣椒植株中的分布以及植物所遭遇的氧化应激。此外，这些改良剂可能会改善土壤酶活性、镍固定指数和植物物候性状。因此，旨在通过改善土壤健康和辣椒生产力，进行有益的科学规划和研究，以恢复和修复住所、生物资源，并最大限度减少生活在营养贫瘠的镍污染土壤中的人们的痛苦。
