动物尸体无害化处理物对油菜生长及重金属富集特征的影响

采用室内盆栽试验,以畜禽养殖场动物尸体无害化处理物为有机肥,研究了单施化肥(NPK)、化肥+单倍有机肥(NPK+M)、化肥+倍量有机肥(NPK+2M)三种施肥方式对油菜生长、叶片生理特性及植株和土壤中重金属积累的影响,探讨施用动物尸体无害化处理物在蔬菜种植方面的安全性。结果表明:与NPK处理相比,NPK+M和NPK+2M处理可显著提高油菜地上部干重50.53%~221.05%(P0.05);同时,NPK+2M处理还可使油菜中叶绿素含量(SPAD)及净光合速率(Pn)显著提高22.85%和21.98%(P0.05);NPK+2M处理条件下三种主要抗氧化酶超氧化物歧化酶(SOD)、过氧化氢酶(CAT)和过氧化物酶(POD)的活性均达到最高,同时膜脂过氧化产物丙二醛(MDA)含量较NPK处理显著降低(P0.05)。与NPK相比,NPK+M和NPK+2M处理土壤中Cr、Cu、Cd、Pb的浓度均出现不同程度的增加,其中NPK+2M处理条件下Cr、Cd元素含量与NPK处理相比有了显著提高(P0.05),而Cu、Pb元素含量与NPK处理相比无显著差异(P0.05),NPK+2M处理土壤中Cr、Cu、Cd、Pb含量远低于《土壤环境质量标准》(GB 15618—1995)中Ⅱ类土壤污染物限量标准。NPK+2M处理的油菜植株地上部、地下部重金属含量与NPK处理相比均无显著增加(P0.05),其地上部Cr、Cd和Pb含量远低于《食品安全国家标准》(GB 2762—2012)对新鲜蔬菜中重金属污染物含量的限制。

Effects of organic manure from animal carcasses on Brassiacampestris L. growth and soil heavy metal accumulation

A pot experiment was conducted to explore the feasibility of applying harmlessly-treated animal carcass manure from livestock and poultry farms to vegetable cultivation. The growth of Brassiacampestris L. and soil heavy metal content were measured under three different treatments, including chemical fertilizer(NPK) only, combined chemical fertilizer plus manure(NPK+M), and combined chemical fertilizer plus double manure(NPK+2M). Results showed that both NPK+M and NPK+2M significantly increased shoot dry weight by 50.53%~221.05%, compared with NPK(P<0.05). In NPK+2M treatment, relative chlorophyll content(SPAD) in fresh leaves and leaf net photosynthetic rate significantly increased by 22.85% and 21.98%, respectively, as compared with NPK treatment(P<0.05). Activities of superoxide dismutase(SOD), catalase(CAT), and peroxidase(POD) were found to be the highest, meanwhile maloaldehyde(MDA) was lowest in NPK+2M treatment. Compared with NPK, both NPK+M and NPK+2M increased soil Cr, Cu, Cd and Pb concentrations, but Cu and Pb content was not different between NPK+2M and NPK treatment(P<0.05). However, the content of heavy metals in NPK+2M was far lower than the class II limits of the soil environment quality standards. In addition, the heavy metal content in Brassiacampestris L. aboveground and belowground parts in NPK+2M showed no significant increases, compared to NPK treatment(P >0.05), and the Cr, Cd and Pb content in the aboveground part was much lower than the National Food Standards for vegetables. These results would shed light on the safe use of harmlessly-treated animal carcasses.