【作者】 王立民；

【导师】 王宏燕；

【作者基本信息】 东北农业大学 ， 农业生态学， 2008， 硕士

【摘要】 本课题研究松嫩平原退化黑土（由于人为掠夺性的生产方式,使黑土层犁底层加厚,耕层变浅,土壤结构性差,土壤板结,容重增大,孔隙减少,持水量降低,保水保肥性能减弱）在不同培肥处理下,与氮素转化有关的土壤功能细菌（自生固氮细菌、氨化细菌、硝化细菌、反硝化细菌）和土壤酶（脲酶、过氧化氢酶）的变化规律,进而分析对土壤氮素转化的功能如自生固氮作用强度、氨化作用强度、硝化作用强度和反硝化作用强度的动态影响,以及对硝态氮不同土层淋溶和植物收获的氮素输出量的影响,从而对土壤中氮素转化机理进行深入的理论研究,为生产实践中科学合理的利用土壤氮素和指导氮素肥料的施用提供科学依据,为保护黑土资源、减少农业非点型污染等提供科学参考。本试验得出的主要结论有:1.不同培肥处理对土壤自生固氮细菌、土壤氨化细菌、硝化细菌、反硝化细菌影响差异显著。施用农肥处理能促进土壤自生固氮细菌的生长,单独施用化肥对氨化细菌影响不大,而对反硝化细菌生长有一定的促进作用。单独施用农肥、农肥化肥配合施用提高了土壤自生固氮细菌、土壤中氨化细菌、硝化细菌及反硝化细菌数量。2.不同培肥处理对土壤自生固氮作用强度、土壤氨化作用强度、硝化作用强度、反硝化作用强度影响均达到显著水平。各培肥处理对自生固氮作用强度均产生抑制作用,农肥处理抑制的作用较大。农肥的单独施用及农肥化肥配比施用均可提高土壤氨化作用强度,纯化肥的施用一定程度上降低了土壤氨化作用强度。农肥化肥单独施用及配比施用对硝化作用强度具有促进作用。对反硝化作用强度影响最大的是化肥单独施用处理,化肥能增强反硝化作用强度。3.脲酶活性在花期达到最大值,在大豆整个生育期,各培肥处理中化肥低量处理和农肥处理能更好的提高脲酶活性;在施入等量氮素的前提下,低氮素含量处理的过氧化氢酶活性高于高氮素含量处理;农肥施用处理的过氧化氢酶活性高于化肥施用处理。4.土壤pH值、土壤含水量对与土壤氮素转化有关的细菌及生化作用强度都有一定的影响。pH的升高促进了氨化细菌的生长却抑制了反硝化细菌的生长。土壤温度和氨化细菌呈正相关,在一定的温度范围内温度的升高促进了氨化细菌的生长繁殖,土壤氨化细菌可产生氨化作用。5.各培肥处理的NO₃^--N淋溶量显著高于对照,差异显著。与对照相比化肥处理的NO₃^--N淋溶量高于农肥处理。在施用等量氮素条件下,农肥施用处理的淋失率要远远小于化肥施用处理,化肥处理的氮素损失较农肥施用处理多。6.土壤NO₃^--N含量与土壤NO₃^--N淋溶量有直接的关系,NO₃^--N淋溶量随着土壤NO₃^--N含量增加而增加,30cm深度土壤NO₃^--N含量与硝氮淋溶量的相关系数为r=0.726,60cm深度土壤NO₃^--N含量与硝氮淋溶量的相关系数为r=0.836**,可以看出与对照相比各施用处理均能使土壤中氮素的淋溶量增加,以化肥处理的淋溶量增加最多,损失量也是最大的,而农肥处理和农化配比使用处理能有效的减少氮素的淋失。7.各培肥处理提高了大豆植株中的氮素含量,提高最显著的为农肥高量施用处理,,其次为农肥低量施用处理和化肥高量施用处理,再次为农化等量施用处理,提高最少的为化肥低量施用处理,说明农肥处理能够增加植物中的氮素含量。8.不施肥的土壤生态系统就是一个自然的生态系统,它的氮素输入主要来自于大气固氮,因此对照处理自生固氮作用强度高于其他施肥处理。其固氮的量与作物吸收利用、土壤中挥发淋溶的氮相比,是很少的,最终导致土壤氮素的缺乏,而农肥、化肥的施用能够有效地增加土壤氮库储量。更多还原

【Abstract】 The paper studied the rules of functional bacteria diversification（self-nitrogen-fixation bacteria,ammonifying bacteria,nitrobacteria,denitrobacteria ） on the nitrogen transitions and soil enzyme transformation（urease,catalase） under the different fertilizer managements in agro-ecosystem of the black soil district in Songnen Plain and effects on the intensity of the spontaneous nitrogen fixation,the intensity of the process of ammonification,nitrification and denitrification in soils in order to further study the mechanism of nitrogen transition in soils,supply scientific basis on reasonable use of the nitrogen in soil and guidance for the nitrogenous fertilizer utilization in field practice and provide scientific reference for protecting black soil resource, reducing agricultural non-point pollution and producing the organic food.Main conclusions educed from this experiment were as follows:1.The effect of different fertilizing treatments on soil ammonifying bacteria,nitrobacteria, denitrobacteria was significant.The impact of separate fertilizer on ammonifying bacteria was not remarkable,but it could improve the growth of denitrobacteria.The manure application could improve the quantities of soil ammonifying bacteria,nitrobacteria and denitrobacteria.2.In the whole growing period,the effect of different fertilizing treatments on the soil ammonification intensity,the nitrification intensity and denitrification intensity was significant.The separate manure and fertilizer application and combining of manure and fertilizer could improve soil ammonification intensity,whereas the fertilizing application could decrease soil ammonification intensity.The separate manure and fertilizer application and combining of manure and fertilizer treatments play the role in promoting nitrification intensity.3.The separate manure and fertilizer application and combining of manure and fertilizer treatments could improve the soil urease activity and catalase activity.However,the impact on soil enzyme was different among them;the effect of manure application is higher than that of fertilizer on improving the soil caralase activity.4.Soil pH value,soil water content had definite impacts on the soil bacterium related with soil nitrogen transformation and biochemical intensity respectively.The higher pH value facilitated the growth of ammonifying bacterial,whereas restrained the quantities of denitrobacterial.5.NO₃^--N leaching under different treatments of manure and fertilizer application were significantly higher than that of comparison and had obvious differences.To compare with comparison,the rate of NO₃^--N leaching in the treatment of fertilizers was higher than the treatment of manure.Under the condition of equal amount of nitrogen,the rate of leaching loss in the treatment of manure was less than the treatment of fertilizers,whereas the loss of nitrogen in the treatment of nitrogen was more than the treatment of manure.6.The content of NO₃^--N in soil was relative directly to the content of NO₃^--N leaching.The rate of NO₃^--N leaching was increased with the content of NO₃^—N in soil.The relative coefficient was r = 0.726 with the content of NO₃^—N under 30cm depth in soil and Nitrate Leaching.The relative coefficient was r = 0.836^**with the content of NO₃^—N under 60cm depth in soil and Nitrate Leaching.We can draw that with the compare to comparison the different treatments of manure and fertilizer can increase the rate of nitrogen leaching in soil.The leaching under the fertilizer application treatment was the most and the rate of loss was maximal,whereas the treatments of mamure application and the treatments of mix mamure and fertilizer application can reduce effectively the loss of nitrogen.7.All of Manure and fertilizer applications increased the content of nitrogen in soybean plant, which was significantly increased under high fertilizer application,and in the next place was under low farming fertilizer application and the high manure,and again was under half of manure and half of fertilizer application,and was the lowest under low manure application.From it we can draw the conclusion the fertilizer application can increase the content of nigrogen in plant.8.Soil ecosystem with no fertilizers was an exhausted ecosystem,the input of nitrogen came mainly from nitrogen-fixation in the atmosphere,therefore the intensity of the spontaneous nitrogen fixation under control application was higer than other fertilizer application effectively.更多还原