济南小清河污水灌溉对玉米早期生长发育及其某些生理指标影响的研究

【作者】 李兆智；

【导师】 苗明升；

【作者基本信息】 山东师范大学 ， 环境科学， 2006， 硕士

【摘要】 人类对于污水的利用由来已久,早在公元前雅典就开始了污水灌溉,大面积的利用污水进行灌溉在世界各地已有近百年的历史。我国的污水灌溉始于上世纪四五十年代,由于我国水资源紧缺,所以污水灌溉得到了迅速发展,目前天津、北京、石家庄、济南、沈阳等地都成为全国著名的污灌区。城市污水经处理达标后再用于农田灌溉是污水资源化和污水净化的有效途径。一方面由于土壤的自然净化能力,对污水残留毒物进一步净化、解毒,减轻了污水对环境的危害;另一方面由于污水中含有大量的营养物质被植物吸收,又促进了农业生产;同时,污水得以重复利用,还缓解了我国水资源紧张的问题。但是由于我国的污灌技术还比较落后,相应的政策法规不够健全,特别是在污灌过程中对水质的要求不严格,因而污灌常常会引发一系列问题,其中主要的就是污灌对作物生长发育的不良影响。不少污灌区直接用未经任何处理的污水浇灌作物、蔬菜,势必对作物的生长发育、生理指标、品质等产生影响。对此国内外已有不少的研究,但是不同研究的结果不尽相同,这主要是由于污灌水的水质不同造成的。不同地区的污灌水来源不同,处理程度不一,因此进入农田的水质状况差异较大,对作物的影响也有差别。小清河污灌始于1956年,据今已有50年历史,现在济南小清河沿岸污灌已较为普遍。由于大量的生活污水和工业废水的排入,使近年来小清河污染较严重,而沿岸农民多是直接从小清河引用未经处理的水进行农业灌溉,因此,对作物的生长发育及生理代谢会有一定的影响,本工作即对小清河污水灌溉对作物产生的影响进行探讨。以前对于污水灌溉的研究大多集中在小麦和水稻两种作物,对玉米的研究极少,所以我们以玉米为材料,采用盆栽的方法,用不同浓度的污水进行处理,系统研究了小清河济南段污水灌溉对玉米早期生长发育及一些生理代谢指标、根尖细胞学等的影响,得出以下结论:1)低浓度的污水处理可以促进玉米种子萌发的速度,100%浓度组的污水处理抑制其萌发速度,但不同浓度的污水处理对玉米最终的萌发率影响不大。2)各浓度的污水对于玉米早期的生长发育基本都有促进作用,其促进作用随更多还原

【Abstract】 Sewage has been used for an age. For example, Athens had used sewage to irrigatecrops B.C. and it is almost a hundred years to sewage for large acreage over the world. Inour country, sewage was also used to irrigate crops from forties or fifties in the lastcentury, and sewage irrigation gets a rapid development due to the shortage of waterresource. At present, Tianjin, Beijing, Shijiazhuang, Jinan and Shenyang are the famoussewage irrigation regions.It is an effective method to make use of the municipal sewage which has beentreated to some extent for the irrigation of agricultural land. For one side, it can depurateand detoxicate the remains of poisons and diminish the pollution of sewage due toedaphic clarifying capacity. For another, it also promotes agricultural production as aresult of nutritious substance contained in the sewage absorbed by plants, and thismethod can also relieve the problem of water resource scarcity by recycle. But sewageirrigation in our country lags in technology, and corresponding policies and codes are notenough healthy, especially requisition of water quality is not rigorous in sewage irrigation,which usually bring about a series of problem. The main problem among them is theadverse effect of sewage irrigation on the growth and development of crops.Sewage used directly to irrigate crops without any treatment certainly will affectcrop’s growth and development, physiologic index and character. Some researches havebeen reported about that both here and abroad. But the researches are different from eachother, perhaps it is due to the different water quality in different regions, which givedifferent effects on the crops.It is about fifty years since sewage irrigation from Jinan Xiaoqing river began in1956, and now becomes very common along the river. Recently, however, Xiaoqing riveris somewhat severely polluted because of domestic sewage and industrial wastewater.Farmers directly draw water from the river without any treatment to irrigate their cropsso that the development and physiological metabolism of crops may be affected to someextent. This study is to research and discuss the effects of sewage irrigation formXiaoqing river on the crops.The former researches about the effect of sewage irrigation mainly focused on twocrops, that are wheat and rice, however, there are few reports on maize. We use maize asresearch materials and, though potted method, systematically study the effect of differentconcentration sewage of Jinan Xiaoqing river on the early growth, physiologicalmetabolism index and root tip cells of maize. The main results are followed:1. Light concentration sewage can promote the sprouting of maize and 100%concentration sewage can inhibit the sprouting of maize, but final sprouting ratio is lessaffected.2. All concentration sewage can promote maize’s growth and development. But with theincrease of sewage’s concentration, the promotion enhances at first and then descendsgradually. But it works as inhibitor when we irrigate maize with high concentrationsewage from the Xiaoqing river.3. The chlorophylla content of maize leaf descends gradually when maize are irrigatedwith sewage and the chlorophylla a is especially sensitive. The value of chlorophylla band chlorophylla a/b descends gradually when maize are irrigated with pure sewage,and it is harmful to the photosynthesis of maize.4. They are significant signs about whether plants are destroyed or the damaged degreethat permeability of plasma membrane and content of MDA. Our researches indicate thatthe content of MDA obviously increased in leaves of maize and the plasma membranepermeability augmented, and we draw a conclusion that maize’s physiological functionsare damaged when maize are treated with sewage.5. POD in the active oxygen elimination system of maize leaves descend after 50%concentration sewage irrigation from Xiaoqing river, but CAT does not descendapparently. Both descend gradually when irrigated with pure sewage. Active oxygenelimination system is damaged due to POD activity descending, which leads toaccumulation of active oxygen and do harm to maize.6. micronucleus tests of maize’s root tip indicate that sewage irrigation can obviouslyincrease maize’s root tip micronucleus ratio, which have genetical toxicity to maize.Analytic results on water quality contamination index show that 50% concentrationsewage from Xiaoqing river belongs to light contamination and 100% concentrationsewage belongs to heavy contamination.Thus it can be seen, water in Xiaoqing river is polluted severely and can not be useddirectly to irrigate agricultural lands. Sewage from Xiaoqing river without any treatmentdoes little harm to maize’s early growth and development seen from exterior figure, butits physiological function is damaged obviously, which must affect the maize’s laterdevelopment, output and quality of production. Low concentration water from Xiaoqingriver is less contaminated and its harm to maize’s physiology is little, which to someextent can promote growth and development. So we suggest that sewage from Xiaoqingriver should be combined with clear water to irrigate crops or rotation irrigation be taken.更多还原