【作者】 田育军；

【导师】 胡恒觉；

【作者基本信息】 甘肃农业大学 ， 作物栽培学与耕作学， 2000， 博士

【摘要】 选用中国农业大学昌平长期定位试验站14年鸡粪与化肥不同施肥处理的土壤（N₀P₀、N₀P₀M、N₁P₀、N₁P₀M、N₂P₀、N₂P₀M、N₀P₂、N₀P₂M、N₁P₂、N₁P₂M、N₂P₂、N₂P₂M、N₂P₂K、N₂P₂KM），首先研究了烘干温度（40、60、80和105℃）、浸提温度（40、60和80℃）与浸提时间（0.5，1，1.5，2，4，6，8和10小时）对土壤中铵态氮、硝态氮和易矿化有机态氮测定的影响；通过温室盆栽试验研究了土壤易矿化有机态氮和微生物态氮的生物有效性以及长期不同施肥处理对土壤微生物态氮含量的影响；通过¹⁵N示踪试验研究了不同土壤N库条件下肥料¹⁵N的交互作用；并通过室内培养试验研究了硝化抑制剂对土壤N素转化的影响。其结果如下： 烘干温度为40、60、80和105℃时，土壤可侵提有机氮含量随烘干温度的升高而增加；各烘干温度下所测得的土壤有机氮与小麦植物吸氮量的决定系数分别为（r²）0.0835、0.0689、0.7862和0.7661，其中80℃和105℃的相关性达显著水平（p＜0.05）。浸提温度80℃时，2小时内可浸提有机氮的数量随浸提时间的延长而增加，2小时后趋于稳定；浸提温度80℃时所测得的土壤有机氮与小麦植株吸氮量的决定系数达显著水平（r²=0.7755）。烘干温度和浸提温度对铵态氮、硝态氮的影响基本一致，即随着温度的升高，铵态氮含量上升，硝态氮含量稍有下降。 对14个土壤处理在不施肥或只施磷、钾肥的生物试验条件下土壤供氮潜力的研究表明：无论是以基础土样还是以生物试验前后土壤各氮素的变化量来衡量土壤的供氮能力，均只有硝态氮和总氮能很好地反应土壤的供氮情况，其决定系数达显著水平（p＜0.05），r²分别为0.7174、0.6758、0.7737、0.7376、0.7261和0.6570；有机肥、氮、磷、钾肥对土壤氮库的作用研究表明， 有机肥有明显的培肥地力的作用，施有机肥的处理与相对应的无 机肥处理相比，其硝态氮、有机氮和总氮的变化量达显著差异水 平bo．05厂 氮肥的施用对提高土壤的硝态氮、总氮有明显的促 进作用k狈．05厂 而磷肥的施用，仅在高氮或施用有机肥的处理 有促进作用，低氮或不施肥的处理却表现为负作用关系。钾肥与 氮、磷和有机肥的配合施用，可提高土壤的供氮能力；小麦植株 的生物量、吸氮量与原土壤施氮水平的高低、有机肥的施用与否 成—一对应关系。经多元回归分析，与土壤各氮素的基础含量或 种植小麦前后的变化量均达显著或极显著正相关关系，其诀定系 数分别 为 r；‘＝0．5355，r、‘＝0．6170 r。’＝0．7041。‘＝0．7261， I’sz＝0．6852，r6z＝0．7963。 对14个处理土壤的微生物态氮含量在小麦播前、收获后的变 化情况，以及土壤微生物氮作为土壤供氮指标的可行性的研究表 明：土壤的微生物氮含量明显受土壤的施肥方式影响，有机肥的 影响力最为显著，达显著差异水平bo．05厂 随着氮、磷化肥施 肥量的增加，微生物态氮也增加趋势，且处理间多数能达显著差 异水平加O．05入但收苗后的土壤微生物态氮量均无明显性差异。 经相关分析，播前土壤微生物态氮含量与作物产量、吸氮量有显 著正相关，决定系数分别为（r‘）0．7165和 0．6978。 选择昌平长期定位试验中，二个施氮水平以及施用和不施用 有机肥的土壤四种（N。P，N。P、M、N、P。N、P，M）所进行的历N示踪试验 结果表明：就植株吸收的总氮，在试验初期无差异，而到中后期 则表现出明显差异O狈．05人 就植株吸收的肥料氮，在试验初期， 原不施氮的明显高于施氮的无机肥处理土壤，但中、后期则相反。 植株吸收的土壤氮，除第三周的与同期植株吸收的肥料氮趋势相 反外，而第四、五周的均与同期植株吸收的肥料氮趋势一致；长 期施和不施有机肥，对小麦植株吸收外源氮有明显影响b狈．05厂 2 J 但主要体现在施低氮化肥处理间，而高氮处理间则无差异；全期 试验结果均表明，小麦植株吸收的肥料氮主要集中在植株的地上 部；在计算植株对肥料氮的利用率时，差减法高于‘叫示踪法的计 算结果；试验结果显示，外源氮的施入，对长期不同施肥处理的 土壤氮，均存在正激发（起爆）效应。 选用队POM和N＊两个长期不同施肥处理上壤，研究施入尿素 后，土壤对尿素氮转化及其对施入硝化抑制剂DCD的抑制作用的 影响。结果表明：加入DCD能维持较长时间相对较高浓度的按态 氮。从而推迟硝态氮高峰值的来临；长期不同施肥处理土壤，就DCD更多还原

【Abstract】 This study was conducted at the long梩erm location test station of Chinese Agricultural University. The experimental soil samples (N0P0,N,P0, N2PQ, 2~ 2? 2K, NQPQM, 1~ N2PQM, NQP2M, N,P2M, N2P2M, N2P2K M)of which the chemical fertilizers and chicken dung have been applied for 14 years were used for the experiment. There are several influences factors on the N variations in the soil were studied. 1) The influences of oven temperature (400C, 600C, 800C and l050C), extracting temperature (400C, 600C and 800C) and extracting time (0. 5,1,1. 5, 2, 4, 6, 8 and 10 hours) on the levels of ammonia nitrogen(NII4~), nitric nitrogen(N03), easy mineralizing organic nitrogen(N梠rganic) were studied. 2) the pot cultivation method was used for the study of the influences of biological efficiency of N梠rganic, microbial nitrogen biomes(SMB桸) and different forms of fertilization on the level of SMB桸 in the soil were also studied in the experiment. 3) N? tracer technique was applied to study the interaction between soil N and Fertilizer N,and 4)green house cultivation experiment was carried out for investigation of the influences of inhibitor(DCD) on transition of soil nitrogen. Through studying the influence of different oven drying temperatures, extracting temperatures and times of 14 soils on ammonia nitrogen, nitric nitrogen, easy mineralizing organic nitrogen and its biological efficiency, The following results were attained: the quantity of soil extractable organic nitrogen increased with the increasing of oven drying temperature from 400C, 600C, 800C to 1050C. The results of multiple comparison were c,c,b and a(p<0.05). The determinant coeffiency (r2) of soil organic nitrogen and uptaking桸 of wheat plant were 0. 0835, 0. 0689, 0. 7862 and 0. 7661, respectively, only the correlation coefficiency was significant between the treatment of 800C and 1050C;At the extracting temperature of 800C, the organic nitrogen increased within the beginning 2 hours and went to stable late, the determinant coefficient of the quantity of soil nitrogen and uptaking桸 was significant(r2~0.7755).The above two ways had the same influence on 5 ammonia nitrogen and nitric nitrogen, that was with the increasing of temperature, quantity of ammonia nitrogen increased while nitric nitrogen抯 decreased. The study of soil nitrogen supply potentiality of 14 soil treatments under the biological experiment condition of supplying no fertilizer or only supplying phosphorous and potassium fertilizer showed that only nitric nitrogen and total nitrogen content could reflect the soil nitrogen supply capacity well when different kind of nitrogen forms in foundation soil sample or in soils of before and after the biological experiment were used to evaluate the nitrogen supply capacity, it determinant coefficient was significant(p<O.05) and r2 were 0.7174, 0.6758,0.7737,0.7376,0.7261 and 0.6570 respectively;The effect of applying manure, N,P and K fertilizers on the soil nitrogen pooi were that manure could enrich the soil obvious, and the nitric nitrogen, organic nitrogen and total nitrogen content increased significant (p<0.05)comparing with that only applying inorganic fertilizer; Applying nitrogen fertilizer could increased soil nitric nitrogen and total nitrogen significantly while applying phosphorous fertilizer increased them only in the treatments of high quantity nitrogen or manure更多还原