秸秆改良农田土壤中氮磷形态分布及玉米生长发育特征

发布时间：2018-02-25 15:38

  本文关键词： 秸秆改良 农田土壤 吸附 淋溶 形态 玉米生长发育　出处：《吉林大学》2016年博士论文　论文类型：学位论文

【摘要】：随着我国农业的快速发展,化肥施用量逐年递增,目前我国单位面积化肥用量已远远超过世界平均水平。大量施用化肥带来了诸多生态和环境问题,肥料利用率低导致环境污染的现象已经越来越明显。秸秆是农业生产系统中重要的生物质资源,其中含有大量的有机质、氮、磷、钾以及微量营养元素,如果将秸秆资源合理利用,对提高农业的可持续生产能力将具有十分重要的作用。秸秆还田技术能够将秸秆中植物生长所需要的部分营养元素归还到土壤中,减小土壤养分的耗竭程度,这是直接利用秸秆资源的有效途径。目前,我国对秸秆还田技术的应用已有大量研究,但对于不同施肥模式下秸秆还田后对土壤氮和磷形态以及玉米生长发育的影响缺乏系统研究。本文以辽河源头区耕地土壤为研究对象,通过对秸秆性能的表征、秸秆改良土壤的吸附和淋溶实验、盆栽试验和田间试验,研究传统施肥模式和测土配方施肥模式下,将破碎秸秆、腐熟秸秆、0.5%秸秆炭(炭/土)、1.0%秸秆炭和2.0%秸秆炭分别还田后对土壤氮磷形态和玉米生长特征的影响,以期为利用秸秆还田有效控制面源污染提供理论依据。(1)电镜扫描结果表明,破碎秸秆表面比较粗糙,秸秆纤维清晰可见,腐熟秸秆表面比破碎秸秆规则、有序,秸秆炭表面粗糙、孔壁被烧蚀;傅里叶红外光谱图解析结果表明,破碎秸秆、腐熟秸秆和秸秆炭均含有酚羟基或醇羟基及含磷官能团。(2)模拟吸附实验结果表明,不同处理的秸秆添加土壤对铵态氮吸附速率和吸附量大小均为秸秆炭破碎秸秆腐熟秸秆;对磷酸根吸附速率和吸附量大小均为秸秆炭破碎秸秆,腐熟秸秆对磷酸根负吸附。Freundlich方程能更好的描述铵态氮和磷酸根的吸附热力学过程,吸附动力学都符合伪二阶动力学方程。(3)模拟淋溶实验结果表明,秸秆不同处理方式处理的土壤对硝态氮比铵态氮更容易淋失,水溶性磷变化较小;不同处理的秸秆添加土壤对土壤氮磷的淋失阻控作用大小为秸秆炭破碎秸秆腐熟秸秆,增强土壤对氮磷的吸附能力的秸秆炭处理,可以减少土壤氮磷的淋失量。(4)盆栽试验和田间试验结果表明,对于传统施肥模式和测土配方施肥模式秸秆炭处理能增加土壤铵态氮、硝态氮、速效氮和全氮的含量,随秸秆炭添加量增加而增加,最高添加时(2.0%秸秆炭处理)增加更明显;腐熟秸秆和破碎秸秆对铵态氮、硝态氮、速效氮和全氮的影响不明显;不同处理的秸秆能增加土壤水溶性磷和速效磷含量,但土壤全磷量下降。田间试验结果表明,传统施肥模式下,0-20cm土层中秋季的土壤速效氮、铵态氮、硝态氮含量高于春季;测土配方施肥模式下,0-20cm土层中春季的土壤速效氮、铵态氮和硝态氮含量高于秋季;不同施肥模式下0-40cm土层中秋季的土壤全氮含量高于春季。测土配方施肥模式下在0-0.25mm和0.25-0.5mm粒径中土壤全氮含量高,0.25-0.5mm和0.5-1mm粒径中土壤全磷含量高。(5)在不同施肥模式下,秸秆不同处理方式对玉米株高促进作用的顺序为:2.0%秸秆炭1.0%秸秆炭0.5%秸秆炭腐熟秸秆破碎秸秆;秸秆炭处理均能提高玉米的叶宽;在传统施肥模式和测土配方施肥模式下,盆栽试验秸秆不同处理单穗籽粒重提高4%-8%,田间试验单穗籽粒重提高5%-7%;秸秆炭处理都能提高玉米产量(P0.05)。综上,在测土配方施肥模式下秸秆炭对减少土壤氮磷的流失及促进玉米生长发育有积极作用,揭示了秸秆炭对土壤氮磷形态分布的影响机制,研究结果对于指导辽河源头区合理施肥、有效控制面源污染具有重要意义。
[Abstract]:With the rapid development of our country agriculture, fertilizer consumption increased year by year, China's per unit area of chemical fertilizer has far exceeded the average level of the world. A large number of chemical fertilizers has brought many ecological and environmental problems, low fertilizer utilization rate leads to environmental pollution phenomenon is more and more obvious. The straw is an important biomass resource in agricultural production system. Which contains organic matter, large amounts of nitrogen, phosphorus, potassium and trace elements, if the rational use of straw resources, will play a very important role to increase the production capacity of sustainable agriculture. Straw also field technique can be part of nutrient elements in straw plant growth to return to the soil, reduce soil nutrient depletion degree this is the effective way of direct utilization of straw resources. At present, the existing of straw returning technology application in our country a lot of research, but for under different fertilization patterns The effects of straw application on soil nitrogen and phosphorus form and the growth of maize. The lack of arable soil in Liaohe River Basin as the research object, through the characterization of straw properties, adsorption and leaching experiment of straw modified soil, pot experiment and field experiment research of traditional fertilization and fertilization mode. The crushed straw, rotten straw, 0.5% straw charcoal (carbon / soil), 1% straw carbon and 2% straw charcoal respectively after returning on the growth characteristics of nitrogen and phosphorus in soil and maize, in order to provide theoretical basis for the use of straw to effectively control non-point source pollution. (1) SEM results showed that straw crushing the surface is rough, straw fiber is clearly visible, rotten straw straw surface than broken rules, orderly, straw carbon surface roughness, the hole wall is ablated; Fourier transform infrared spectra analysis results show that the broken straw compost 绉哥�嗗拰绉哥�嗙偔鍧囧惈鏈夐厷缇熷熀鎴栭唶缇熷熀鍙婂惈纾峰畼鑳藉洟.(2)妯℃嫙鍚搁檮瀹為獙缁撴灉琛ㄦ槑,涓嶅悓澶勭悊鐨勭Ц绉嗘坊鍔犲湡澹ゅ�归摰妫�

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