镉污染稻区油菜-中稻替代双季稻种植的可行性研究

Study on the Feasibility of Alternative Planting of Rapeseed-Middle Rice to Double Cropping Rice in Cadmium Polluted Rice Area

为了探讨镉污染稻区油菜-中稻替代双季稻种植的可行性,在湖南省湘潭县中度镉污染稻田开展大田试验,研究了油菜-中稻与双季稻模式下的作物生育进程、产量、经济效益与镉含量。结果表明,双季稻、油菜-中稻均能在10月20日前成熟;双季稻早、晚稻产量分别为5233.7和6298.3kg/hm^(2),油菜和中稻产量分别为1875.5和7531.0kg/hm^(2),中稻产量较早、晚稻产量分别提高43.9%和19.6%;与双季稻模式相比,油菜-中稻模式成本降低13.5%,产值提高2.1%,纯收入提高42.6%,总纯收入与劳动力比值升高38.5%;早、中、晚稻根、茎、叶和籽粒等器官镉含量差异明显,均表现为晚稻>中稻>早稻的趋势;糙米镉含量在0.43~0.82mg/kg之间,油菜籽镉含量为0.11mg/kg。综合种植季节、产量、经济效益和籽粒镉含量来看,油菜-中稻模式可作为镉污染双季稻区替代双季稻的种植模式。

To explore the feasibility of alternative planting of rapeseed-middle rice mode for double-cropping rice mode in cadmium-contaminated rice area,a field experiment was carried out to study the growing process,yield,economic benefit,and cadmium(Cd)content between rapeseed-middle rice and double cropping rice mode in paddy field with moderate cadmium pollution in Xiangtan,Hunan province.The results showed that both double cropping rice and rapeseed-middle rice could be harvested before October 20 th.The yield of early rice and late rice were 5233.7 and 6298.3 kg/ha,respectively,and the yield of rapeseed and middle rice were 1875.5 and 7531.0 kg/ha,respectively.The yield of middle rice was 43.9%and 19.6%higher than that of early rice and late rice,respectively.Compared with double cropping rice,the total cost of rapeseed-middle rice decreased by 13.5%,the total output value increased by 2.1%,the total net income increased by 42.6%,and the ratio of total net income to number of labours increased by 38.5%.The Cd contents in roots,stems,leaves,and grains existed clear difference among early,middle,and late rice,which showed the trend of late rice>middle rice>early rice.The Cd content of unpolished rice was between 0.43-0.82 mg/kg,and the Cd content of rapeseed was 0.11 mg/kg.In terms of planting season,yield,economic benefit,and Cd content in grains,the rapeseed-middle rice mode could be used as an alternative planting mode for double cropping rice in the double cropping rice area polluted by Cd.