外加氮源在Cd超标菜地上的应用效果  

Effects of nitrogen addition on above-standard Cd-contaminated soils in vegetable fields

作　　者：王艳红[1] 唐明灯[1] 李盟军[1] 艾绍英[1] 姚建武[1] 罗英健[1] 余丹妮[1] 

机构地区：[1]广东省农业科学院农业资源与环境研究所/农业部南方植物营养与肥料重点实验室/广东省养分资源循环利用与耕地保育重点实验室,广州510640

出　　处：《中国生态农业学报》2016年第2期218-225,共8页Chinese Journal of Eco-Agriculture

基　　金：广东省科技计划项目(2012A030700010);广州市科技计划项目(2014Y2-00521)资助~~

摘　　要：探讨外加氮源对Cd超标菜地不同叶菜吸收Cd及土壤Cd有效性的影响,以明确施氮对土壤Cd的影响效应,并试图对不同氮源的应用效果进行综合评价,为合理利用氮肥来降低叶菜Cd含量提供参考。在Cd含量为0.628 mg·kg?1的Cd超标菜地上,试验研究了氮用量水平为150 kg·hm?2时,4种氮肥(尿素、硝酸钙、硝酸铵、碳酸氢铵)对矮脚葵扇黑叶白菜(Brassica chinensis L.)和白梗尖叶苋菜(Amaranthus mangostanus L.)Cd含量、品质及土壤Cd有效性的效应。结果表明,田间条件下,与不施氮处理相比,4种氮肥均不同程度地增加了Cd超标菜地上2种叶菜产量,降低了其地上部和根系Cd含量。4种氮肥中,尿素对白梗尖叶苋菜的增产效果最好,增产幅度达47.5%;碳酸氢铵对葵扇黑叶白菜的增产效果最好,增幅达59.7%;硝酸钙降低2种叶菜地上部和根系Cd含量的效果均优于其他氮肥,该处理的白梗尖叶苋菜地上部和根系Cd含量分别比对照降低41.6%和24.1%,葵扇黑叶白菜降低32.2%和25.9%。4种氮源对2种叶菜地上部Cd吸收总量、NO3?-N、NO2?-N、维生素C及可溶性糖含量等的影响各异,对土壤p H和DTPA-Cd含量影响也不同。其中,硝酸铵处理的土壤p H分别比对照降低0.12和0.25个单位,而土壤DTPA-Cd含量则显著增加15.3%和14.6%;碳酸氢铵处理则呈相反变化趋势。综合评价结果显示,4种氮肥的综合加权平均值均高于对照处理,以硝酸钙相对最高,表明硝酸钙在Cd超标菜地上的综合应用效果相对最好。因此,在Cd超标土壤上,硝酸钙可作为优选氮源使用。The aim of this study was to explore the effects of nitrogen application on Cd uptake by different kinds of leafy vegetables and on soil available cadmium（Cd） content in above-standard Cd-contaminated soils in vegetable fields. The study also comprehensively evaluated the effects of different nitrogen sources application with the aim of developing strategies to reduce Cd concentration in leafy vegetables by managing the application of nitrogen fertilizers. The experiment was carried out in an above-standard Cd-contaminated vegetable soil to investigate the effects of urea [CO（NH2）2], calcium nitrate[Ca（NO3）2], ammonium nitrate（NH4NO3） and ammonium bicarbonate（NH4HCO3） on yield, quality, Cd content, nitrogen content of two kinds of leafy vegetables — Brassica chinensis L.（BC） and Amaranthus mangostanus L.（AM）. Soil DTPA-Cd content and p H as well as comprehensive effects of nitrogen addition on two vegetables were also investigated. The resultsshowed that all nitrogen sources increased yields and decreased Cd contents in both shoot and root systems of the two leafy vegetables. Furthermore, the highest increase of BC yield（59.7%） was caused by NH4HCO3 treatment, while the largest increase of AM yield（47.5%） was caused by CO（NH2）2 treatment, respectively, compared with control. However, the lowest Cd contents in two kinds of leafy vegetables were observed under Ca（NO3）2 treatment among all nitrogen treatments. Ca（NO3）2decreased Cd content by 41.6% and 24.2%, respectively, in AM shoot and root, by 32.2% and 25.9%, respectively, in BC shoot and root. Moreover, the total content of Cd, nitrate, nitrite, Vitamin C and soluble sugar in the shoot system of the two kinds of leafy vegetables varied with the application of different nitrogen resources. Also similar variances were noted for the changes in soil p H and DTPA-Cd content. NH4NO3 application decreased soil p H by 0.12 and 0.25 and increased soil DTPA-Cd content by 15.3% and 14.6%, respectively, in AM and BC. Howeve

关 键 词：氮源 菜地 Cd超标土壤 叶菜 土壤Cd有效性 

分 类 号：X53[环境科学与工程—环境工程]