【作者】 邱桃玉；

【导师】 周建斌；

【作者基本信息】 西北农林科技大学 ， 农业资源综合利用， 2011， 硕士

【摘要】 以作物秸秆和畜禽粪便等农业废弃物发展农村沼气工程是保护农村环境以及提高资源利用效率的一条有效途径。本研究在分析新疆维吾尔自治区农村沼气发展现状、趋势和存在问题的基础上,针对户用沼气原料短缺和产气量低2个主要限制和影响沼气应用推广的因素,以新疆维吾尔自治区常见的玉米秸秆和小麦秸秆,以及养殖较多的牛、羊粪便为发酵原料,在实验室条件下研究了纯秸秆不同前处理的发酵特性,秸秆配合牛羊粪便实地户用沼气池发酵特性,以及发酵残余物沼液、沼渣在温室大棚蔬菜施肥,南疆绿洲棉花喷施沼液对防治病虫害效果等综合应用方面的研究。得到以下主要结论:(1)室内自然温度发酵前提下,在保持相同发酵浓度、碳氮比的条件下,用绿秸灵和沼液前处理玉米秸秆和小麦秸秆均能产生沼气,玉米秸秆用沼液前处理和小麦秸秆用绿秸灵前处理产气量没有显著性差异。因此在绿秸灵获得困难的条件下,完全可以用发酵正常的沼液前处理秸秆1周后入池,沼液与物料比为1:1较为适宜。产气量多的处理,相应的甲烷含量也比较高,气体也比较纯。但总体来看,甲烷的浓度偏低,最高的只有50%。尤其是不做任何前处理的小麦对照处理甲烷含量仅为37%。(2)户用沼气池利用秸秆替代粪便发酵生产沼气是一条可行的途径,但是在玉米及小麦秸秆入池前必须进行前处理,包括粉碎、添加绿秸灵和N肥、浸湿堆沤等,且启动时间及产气高峰均较纯粪便原料长,即产气较慢,高峰期推迟了15天左右;秸秆与粪便不同配比原料所产沼气量存在差别,秸秆所占的比例过大或过小均不利于发酵产气,仅从总产气量、TS(总固体)产气率及甲烷含量等参数考虑,以50%秸秆+50%粪便为最佳原料配比。则在生产上应提倡秸秆与粪便各占一半的原料配比,发酵产气效率相对较高;纯秸秆原料虽然产气的持续时间长达6个月,但启动时间较长,产气量及TS产气率不如与粪便混合原料,尤其是沼气中的甲烷含量较低,因此,在新疆以养殖业为主的农牧区,应提倡玉米、小麦秸秆与牛、羊等家畜粪便混合原料生产沼气。(3)在北疆地区种植蔬菜,施用沼渣作底肥可以显著地提高土壤有机质、碱解N、速效P的含量,土壤速效钾的变化不明显;沼肥与化肥配合施用可显著提高蔬菜的产量及品质,在保持等量化肥的前提下,蔬菜产量随着沼渣用量的增加,白菜和豆角的最高产量分别比纯施化肥的对照高出38%和69%。此外,施用沼肥还增加了蔬菜中VC含量;在生长期连续喷施三次沼液与喷施农药的处理相比,喷施沼液能够防治豆角病虫害的发生;喷施沼液能够降低蔬菜中农残和硝酸盐的含量,农残值显著地低于喷施农药的处理,综合比较蔬菜的产量、品质和农残以及土壤性状,在设置的10个施肥处理中,以白菜处理4和豆角处理4为最佳方案,即叶菜类:尿素300、三料300、硫酸钾60 kg/hm~2,配施沼渣30000 kg/hm~2;茄果类:尿素225、三料400、硫酸钾75 kg/hm~2,配施沼渣30000 kg/hm~2。(4)南疆绿洲棉产区,由于不同沼气池发酵原料不同,发酵时间不同,所含的微量元素有差异,所以实际生产中进行沼液喷施时,要根据沼液情况,棉花生长期确定合理浓度,配以适当清水。四个处理中以50%浓度沼液喷施最佳,棉花长势好、铃数最多,75%浓度沼液喷施次之。更多还原

【Abstract】 It is an efficient way to use crop straw and manure livestock or poultry and other agricultural residue to protect the rural environment and improve the efficiency of resources.Based on the analysis of the Xinjiang Uygur Autonomous Region’s rural biogas development status, trend and problems, the 2 main factors: Corn straw and wheat straw, and cattle, sheep faeces were used for the fermentation raw material. Pure straw after pretreatment was studied in the laboratory conditions .Straw and manure fermentation characteristics were studied in household biogas pool as well as biogas fermentation residue in greenhouse vegetable fertilization, South Xinjiang oasis cotton pest control effect of biogas slurry comprehensive research of application. The conclusions are as follows:(1)While keeping the same fermentation concentration, and the same ratio of carbon to nitrogen, under the indoor natural temperature, different pretreatment of adding biological agents to corn stalk and wheat straw and adding fermentation liquid to them both can produce biogas. The gas volume has no significant difference between biogas slurry pretreatment of corn straw and wheat straw with biological agents. Therefore when biological agents is difficult to get, we can use the normal fermentation biogas slurry to pre-treat straw about 1 week, keeping slurry and raw material ratio 1: 1 is more appropriate. The more the gas production, the relatively higher the methane content, and the purer the gas content .But on the whole, the methane concentration is low, the highest concentration of which only reach to 50%. Especially CK control of wheat straw, that is, without any pre-treatment, methane content is only 37%.(2)It was a feasible way to use straw instead of manure to produce marsh in the household gas pool, but pre-treatment of the corn and wheat straw must be well done, including crushing, adding biological agents and N fertilizer, wet stack retting and so on. The starting time and gas production peak were longer than the pure fecal material. That is gas production was slow, the peak was delayed about 15 days. Gas volume was different among different ratio of raw material treatments. Too large or too small straw proportion was both not conducive to fermentation. But considering the total gas production, TS (total solids) gas production rate and the methane content etc. parameters, 50% straw + 50% manure is the best ratio of raw materials. So half of the ratio of raw materials should be advocated in the production. Fermentation efficiency is relatively high; while pure straw raw materials can produce the gas up to 6 months, but it took too long time to startup. The gas production and TS gas production rate were not so good as manure mixed with raw materials, especially the low methane content of biogas. Therefore farming and stockbreeding area in Xinjiang, we should promote corn, wheat straw and cattle, sheep and other livestock manure mixed with the raw materials to produce biogas.(3)The vegetable cultivation in north XinJiang, applying biogas residue as fertilizer can remarkably increase soil organic matter, alkali solution N, available P content, yet soil available potassium did not increase significantly; The biogas manure and chemical fertilizer combined application could significantly increase the yield and quality of vegetables. While maintaining the same quantity of chemical fertilizer, vegetable yield increased with the increase of the biogas residue, cabbage and bean yield is respectively 38% and 69% higher than the pure chemical fertilizer ck. In addition, biogas fertilizer also increased VC content in vegetables; compared with spraying pesticides treatment during the growth period, continuous spraying three times biogas slurry can control beans pests; spraying biogas slurry was capable of reducing pesticide residues in vegetables and nitrate content, the pesticide residue value was significantly lower than the pesticide spraying treatment. Comprehensive comparison of vegetable yield, quality and pesticide residues and soil properties, Treatment 4 to Chinese cabbage and bean were both the best scheme, namely to the leafy: urea 300 kg/hm~2, Phosphate fertilizer 300 kg/hm~2, potassium sulfate 60kg/hm~2, 30000 kg/hm~2 of biogas fertilizer was the best scheme; while to the solanum: urea 225 kg/hm~2, Phosphate fertilizer 400 kg/hm~2, potassium sulfate 75 kg/hm~2, 30000 kg/hm~2 of biogas fertilizer was the best scheme.(4)In South Xinjiang oasis cotton area, due to the different raw materials and fermentation time of biogas pool, trace elements were also different, so during the actual production of biogas slurry spraying, we should use it according to circumstances, cotton growth period to determine the reasonable concentration, with the proper water. In this four treatments, 50% concentration of biogas slurry spraying was the best, cotton grew well, cotton bolls were more , 75% concentration of biogas slurry spraying was the second .更多还原