Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, 410125, China; University of Chinese Academy of Sciences, Beijing, 100049, China.
Key Laboratory for Agro-ecological Processes in Subtropical Region, Institute of Subtropical Agriculture, Chinese Academy of Sciences, Changsha, Hunan, 410125, China.
Environ Pollut. 2018 Aug;239:198-204. doi: 10.1016/j.envpol.2018.04.024. Epub 2018 Apr 11.
The research was conducted to investigate the accumulation, distribution and availability of Cd in paddy soil and their relation to Cd in rice plants under 30-year fertilization regimes. Six treatments were involved in the study: control without fertilization (CK), chemical fertilizer (NPK), high nitrogen chemical fertilizer (HN), rice straw incorporation (ST), low and high dosage of manure fertilizer (LM and HM). Total and DTPA extractable concentration of Cd (T-Cd and DTPA-Cd) in bulk soils (20 cm topsoil), profiles (0-60 cm) and aggregates (>2, 1-2, 0.5-1, 0.25-0.5, 0.053-0.25 and < 0.053 mm) were investigated. The Cd concentration in relevant rice plant (roots, stems, leaves, husks and grains) were also analyzed. Manure fertilizers caused T-Cd accumulation in bulk soil with a significant increase of 36.2% in LM and 81.2% in HM. Similar impacts of manure fertilizers were observed in DTPA-Cd in the bulk soil. Further, the HM generated a further accumulation in deeper soil layers, presenting a remarkable increase of T-Cd (28.3%-225%) in 10-40 cm and DTPA-Cd (116%-158%) in 10-30 cm profiles. Moreover, the continuous application of manure fertilizers enhanced the availability of Cd in all aggregate size classes with an increase of 17.3%-87.8% in DTPA-Cd. Organic fertilizers (LM, HM and ST) heightened the content of Cd (38.0%-152%) in all parts of rice plant. The accumulation of Cd in rice plants was directly affected by fertilization regimes and Cd availability in the 10-20 cm soil layers and 0.25-0.5 mm aggregates. In conclusion, long-term application of manures resulted in increasing availability of Cd in aggregates and in topsoil and subsoil layers, which accordingly enhanced the accumulation of Cd in rice plants.
这项研究旨在调查在 30 年施肥制度下，水稻土中 Cd 的积累、分布和有效性及其与水稻植株中 Cd 的关系。该研究涉及 6 种处理：不施肥对照（CK）、化肥（NPK）、高氮化肥（HN）、稻草还田（ST）、低剂量和高剂量有机肥（LM 和 HM）。研究了原状土（20cm 表土）、剖面（0-60cm）和团聚体（>2、1-2、0.5-1、0.25-0.5、<0.053-0.25 和<0.053mm）中 Cd 的总量和 DTPA 可提取浓度（T-Cd 和 DTPA-Cd）。还分析了相关水稻植株（根、茎、叶、壳和粒）中的 Cd 浓度。有机肥导致原状土中 T-Cd 积累，LM 和 HM 分别增加 36.2%和 81.2%。在原状土中 DTPA-Cd 也观察到类似的有机肥影响。此外，HM 在更深的土层中进一步积累，在 10-40cm 处 T-Cd（28.3%-225%）和 10-30cm 剖面处 DTPA-Cd（116%-158%）显著增加。此外，连续施用有机肥提高了所有团聚体粒径等级中 Cd 的有效性，DTPA-Cd 增加 17.3%-87.8%。有机肥料（LM、HM 和 ST）增加了水稻植株各部位的 Cd 含量（38.0%-152%）。施肥制度和 10-20cm 土壤层和 0.25-0.5mm 团聚体中 Cd 的有效性直接影响水稻植株中 Cd 的积累。总之，长期施用有机肥导致团聚体和表土及底土层中 Cd 的有效性增加，从而增加了水稻植株中 Cd 的积累。
