【作者】 张志华；

【导师】 陈为峰；

【作者基本信息】 山东农业大学 ， 土壤学， 2010， 硕士

【摘要】 本文通过盆栽试验研究了污水及再生水的不同灌溉方式对苜蓿生长、品质及土壤的影响,共设置七个处理:清水灌溉(Q)、污水灌溉(W)、再生水灌溉(Z)、污清混灌(W+Q)、污清轮灌(W/Q)、再清混灌(Z+Q)、再清轮灌(Z/Q),结果表明:相对于清水灌溉,再生水及污水灌溉可增加苜蓿的株高及产草量,但在灌溉初期对苜蓿叶面积有抑制作用,长期引用未经处理的污水灌溉不利于苜蓿根系的生长。第一次刈割时各灌溉处理间K含量差异不显著,第二次刈割时污灌、再生水灌溉处理与清水灌溉相比苜蓿K含量分别增加了33.05%和40.68%,第三次刈割时分别增加了12.90%和23.39%。污水及再生水灌溉处理苜蓿Ca含量在第一次刈割时显著高于清水灌溉,但在第二、三次刈割时均低于清水灌溉。再生水的各处理均不利于苜蓿对Fe元素的吸收,污水的各处理对Fe元素的吸收则表现为先促进后抑制的趋势;污水、再生水灌溉能够增加苜蓿体内Cu含量。污水及再生水灌溉不利于苜蓿可溶性糖的积累,但采用混灌及轮灌方式则可显著增加可溶性糖含量。污水灌溉会显著增加苜蓿体内Pb含量,再生水灌溉下Pb含量略微高于清水灌溉,二者之间差异不显著。污水、再生水及其混灌、轮灌处理与清水灌溉相比均会造成重金属Cd积累,污水的各灌溉处理积累程度较各再生水灌溉处理严重。虽然污水灌溉、再生水灌溉等处理能够造成Pb、Cd积累,但其含量仍低于国家标准限量值(GB 13078-2001)。与清水灌溉相比,污水及再生水灌溉处理能显著降低土壤pH值,增加EC值,污水的影响效果比再生水显著。第一次刈割时各灌溉水质处理对土壤无机氮含量影响不明显,第二次刈割时污灌、再生水灌溉处理与清水灌溉相比土壤无机氮含量分别增加了63.59%和35.02%,第三次刈割时分别增加了82.18%和30.72%。污水灌溉下土壤Pb含量在第三次刈割时显著高于其他处理,各再生水灌溉处理在三次刈割中与清水灌溉间的差异不显著。与清水灌溉相比,污灌处理土壤Cd含量在三次刈割中分别增加了33%、117.65%和138.89%,再生水灌溉在三次刈割中分别增加了13.33%、64.71%和61.11%。土壤重金属污染评价表明,在本试验期间内各灌溉水质处理未引起土壤Pb污染,但未经处理的污水灌溉处理造成了土壤Cd污染。本研究认为未经处理的污水不宜用作灌溉,但采用混灌与轮灌方式可适当减缓其不利效应;再生水可作为苜蓿的灌溉用水,但其长期效应仍需进一步深入研究。更多还原

【Abstract】 Pot experiments were conducted to study the effects of different irrigation methods using sewage and reclaimed water on the Alfalfa’s growth, quality and soil environment. Seven treatments were set up: fresh water(Q) irrigation, sewage(W) irrigation, reclaimed(Z) water irrigation, sewage mixed (W+Q) and rotational (W/Q) irrigation with fresh water and reclaimed water mixed (Z+Q) and rotational (Z/Q) irrigation with fresh water.The results indicated that sewage and reclaimed water increased stem length and yield compared with fresh water, but inhibited Alfalfa leaf area in early irrigation. Sewage irrigation also inhibited Alfalfa root growth. Effects of irrigation water quality treatments on Alfalfa K content was not remarkable at the first clipping, but W and Z irrigation showed higher K content than Q irrigation by 33.05% and 40.68% at the second clipping, and by 12.90% and 23.39% at the third clipping. Compared with Q irrigation, W and Z irrigation significantly increased Alfalfa Ca contents at the first clipping, however at the second and third clipping, W and Z irrigation treatments were lower than Q irrigation in Alfalfa Ca contents. The three reclaimed water treatments (Z, Z+Q and Z/Q) restrained alfalfa’s Fe content, and the sewage treatments(W, W+Q, W/Q) promoted the absorption of Fe at the first, but then inhabited; sewage and reclaimed water irrigation increased Cu content of alfalfa.W and Z irrigation were disadvantageous to the alfalfa’s soluble sugar accumulation, but using mixed and rotational irrigation methods increased soluble sugar contents significantly; Pb content in alfalfa was significantly increased under W irrigation , though Z irrigation promoted accumulation of Pb,there was no obvious difference between Z and Q irrigation; The six sewage and reclaimed water treatments(W, Z, W+Q,W/Q,Z+QZ/Q) caused alfalfa Cd accumulation compared with Q irrigation, and the accumulation degree under three sewage treatments was more severe than the three reclaimed water treatments. Although sewage and reclaimed water irrigation caused Pb, Cd accumulation, Pb and Cd contents in Alfalfa were lower thancontamination threshold of National Sanitation Standard (GB 13078-2001).Compared with fresh water (Q) irrigation, sewage (W) and reclaimedwater (Z)irrigation decreased soil pH and increased soil EC , and the influenceof W irrigation was more effective than Z irrigation. Effect of irrigation waterquality treatments on soil inorganic nitrogen was not obvious at the firstclipping, but compared with Q irrigation, W and Z irrigation increased soilinorganic nitrogen contents by 63.59 and 35.02% at the second clipping, andincreased by 82.18% and 30.72% at the third clipping. W irrigationsignificantly increased Pb contents of soil at the third clipping. In threeclippings, the difference between three reclaimed water (Z, Z+Q and Z/Q)irrigation and Q irrigation was not significant. Compared with Q irrigation, Wirrigation increased soil Cd contents in three clippings by 33%, 117.65% and138.89% and Z irrigation increased by 13.33%, 64.71% and 61.11%.Evaluation of heavy metal pollution in soils indicated that during theexperiment, all treatments didn’t cause soil pollution by Pb, but soil waspolluted by Cd under sewage irrigation. Accordingly, sewage shouldn’t beused for irrigation, but after mixed or rotational with fresh water, it canproperly decrease the adverse effects; reclaimed water can be used as a sourceof irrigation in Alfalfa growth for a short period of time and their long-termeffect should be concerned.更多还原