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

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。

Cadmium security analysis of different organic materials and passivators under ryegrass-Guimu 1 hybrid rotation in soils with low Cd environmental capacity

To investigate the influences of different organic manures, passivators and their combinations on cadmium 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 3.19×10⁵ and 2.74×10⁵ 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. Application 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 organic 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 passivators such as lime when using Cd-containing organic manures to produce forage under ryegrass-Guimu 1 hybrid rotation in low environmental capacity soils.