铵态氮肥和腐殖酸协同促进孔雀草对土壤中Cd的去除

为了提升孔雀草(Tagetes patula L.)对镉(Cd)污染土壤的修复潜力,通过田间试验,研究铵态氮肥和腐殖酸对孔雀草生长以及土壤中Cd去除的影响.结果表明,氮肥(N)与氮肥和腐殖酸联用处理(NHA)可显著提高孔雀草的生物量;与对照(CK)相比,NHA和N处理下孔雀草地上部生物量分别提高了 2.49倍和1.52倍(肥东土壤),提高了 2.28倍和1.74倍(长丰土壤).在孔雀草生长期间,氮肥和腐殖酸能够降低土壤pH值,尤其是NHA处理;NHA处理较CK处理在肥东和长丰土壤上pH值分别降低了 0.76和0.84个单位;腐殖酸处理(HA)能显著提高肥东与长丰土壤中DOC的含量.NHA和HA处理能显著促进孔雀草根系生长发育,改善孔雀草的根系形态特征.在肥东和长丰土壤中,与CK相比较,NHA处理土壤有效态Cd含量分别增加了 64.1％和53.1％,孔雀草Cd的累积量分别增加了 7.17倍和4.15倍;NHA处理的土壤Cd去除率最高,在肥东和长丰土壤上分别达到17.06％和14.08％.本研究表明在强化孔雀草修复重金属Cd污染土壤方面,铵态氮肥和腐殖酸的联用具有潜在应用前景.

Ammonium Nitrogen Fertilizer and Humic Acid Synergically Promote the Removal of Cd from Soil by Tagetes patula L.

In order to enhance the remediation potential of Tagetes patula L. on cadmium (Cd)-contaminated soil, field experiments were conducted to study the effects of ammonium nitrogen fertilizer (N) and humic acid (HA) on the growth of Tagetes patula L. and the removal of Cd from soil. The results showed that N treatment and the combined treatment of N and humic acid (NHA) significantly increased the biomass of the plants. Compared with that of the control (CK), the shoot biomass of the plants under NHA treatment increased by 2.49 times and 1.52 times in Feidong soil and 2.28 times and 1.74 times in Changfeng soil, respectively. The N and HA treatments, especially the NHA treatment, reduced the soil pH value during the growth period of the plant. The soil pH value in the NHA treatment decreased by 0.76 and 0.84 units in Feidong and Changfeng soils, respectively. The HA treatment significantly increased the DOC concentration in Feidong and Changfeng soils. The NHA and HA treatments significantly promoted the growth and development of the root system and improved the morphological characteristics of the plant. In the NHA treatment, the available Cd content increased by 64.1% and 53.1% in Feidong and Changfeng soils, respectively. The corresponding values in the accumulation of Cd in plants were 7.17 times and 4.15 times in Feidong and Changfeng soils, respectively. The maximum removal rates of Cd in Feidong and Changfeng soils were 17.06% and 14.08% under the NHA treatment, respectively. The results showed that the combination of ammonium nitrogen fertilizer and humic acid had a potential application prospect in enhancing the remediation of Cd-contaminated soil by Tagetes patula L.