有机物料和钝化剂对低 Cd 环境容量土壤黑麦草与桂牧1号轮作的 Cd 安全分析

摘要

针对南方稻田土壤酸化、重金属 Cd 环境容量小，采用田间小区试验研究改制黑麦草－桂牧1号轮作模式下不同施肥和酸化调理对牧草质量安全的影响。结果表明，有机肥及其与石灰配施显著增加黑麦草与桂牧1号产量，总鲜重分别达3．19×105，2．74×105 kg／hm2，比单施化肥（对照）分别增产43．10％（P ＜0．05），22．73％（P ＜0．05），而石灰、赤泥、稻草等对黑麦草和桂牧1号产量无显著影响；石灰、赤泥、有机肥及有机肥与石灰配施皆能提高土壤 pH 值，降低土壤有效态 Cd 含量及其生物有效性；但有机肥、稻草的施用增加了土壤 Cd 残留。因此，应控制有机肥和稻草的 Cd 含量与用量，以确保土壤的安全可持续利用；同时，低 Cd 环境容量土壤施用含 Cd 有机物料不建议施用石灰等钝化剂，以促进南方牧草种植系统重金属循环减控。%To investigate the influences of different organic manures,passivators and their combinations on cad-mium content in forage,a field plot experiment was conducted under ryegrass-Guimu 1 hybrid rotation in south China,where the paddy soil is typically acidic and has low Cd environmental capacity.The results showed that the yields of ryegrass and Guimu 1 hybrid increased significantly by 43.1% and 22.7%,respectively,with the fresh weights reaching 3.19×10 5 and 2.74×10 5 kg/ha respectively,compared to that of the control after the application of organic fertilizers.Lime,red mud and rice straw exhibited no significant effects on yields.Appli-cation of lime,red mud,organic manures and organic manures combined with lime could increase the soil pH, decrease the soil available Cd content and restrain the bio-availability of Cd.However,the application of organ-ic manures increased the residue of Cd in soils.Therefore decreasing the input level of organic manures or using low Cd-content organic manures should ensure the sustainable use of soil.It is not recommended to add passi- vators such as lime when using Cd-containing organic manures to produce forage under ryegrass-Guimu 1 hy-brid rotation in low environmental capacity soils.