导　　师： 吕家珑;徐明岗

学科专业： 090301

授予学位： 硕士

作　　者： ;

机构地区： 西北农林科技大学

摘　　要： 本试验通过对我国典型农田土壤-黑土、灰漠土、褐土、灌漠土、黑垆土、潮土、塿土、紫色土、黄棕壤、红壤和水稻土上15～28年16个点的长期不同施肥下土壤氮素含量相关数据进行统计分析,以阐明长期不同施肥下土壤氮素含量的时间演变特征及空间差异,为氮肥合理施用提供理论依据。获得的主要结果与结论如下: 1.长期不同施肥处理下土壤氮素含量随时间变化情况不同。长期不施肥/(CK/),北方旱地土壤全氮和碱解氮含量随时间显著下降,年均分别减少0.009 g·kg~/(-1/)和1.07 mg·kg~/(-1/);施用增量氮磷钾+增量有机肥/(NPKM+/),土壤全氮和碱解氮含量随时间显著上升,年均分别增加0.030 g·kg~/(-1/)和2.33 mg·kg~/(-1/);单施氮肥/(N/)、氮磷配施/(NP/)、氮钾配施/(NK/)、氮磷钾配施/(NPK/)、常量氮磷钾+常量有机肥/(NPKM/)和常量氮磷钾+秸秆还田/(NPKS/)处理下氮素含量变化不大。 南方土壤全氮含量在CK、N、NK和NPKS处理下随时间显著下降,年均分别减少0.017、0.014、0.015和0.029 g·kg~/(-1/);在NP、NPK、NPKM和NPKM+处理下变化不大;碱解氮含量在CK、NP、NK和NPKS处理下随时间也呈现显著下降趋势,年均分别减少1.43、1.26、2.10和3.13 mg·kg~/(-1/);而在N、NPK、NPKM和NPKM+处理下变化不大。 不施氮肥会导致土壤氮素肥力降低,施用化肥和配施常量有机物质能够维持北方土壤氮素肥力,高施氮和有机肥条件下北方旱地土壤氮素容易累积;偏施氮肥和氮磷钾配施秸秆还田时,南方土壤氮素肥力降低,氮磷钾配施及其配施有机肥则能够维持其氮素含量稳定。 2.不同的施肥措施下土壤氮素含量不同。北方土壤在NPKM+、NPKM和NPKS处理下,土壤全氮平均含量较不施肥处理分别净高39.9/%、26.9/%和14.1/%,土壤碱解氮平均含量较不施肥处理分别净高44.4/%、32.8/%和26.1/%;NPK处理次之,为11.7/%和14.3/%。南方土壤在NPKM+和NPKM处理下,全氮平均含量较不施肥处理均净高23.6/%,碱解氮平均含量分别净高23.4/%和21.0/%;NPK和NPKS处理全氮平均含量分别净高14.6/%和13.7/%;NK处理碱解氮平均含量净高14.6/%。 3.不同施肥处理对不同类型土壤的氮素含量影响不同。施肥对我国南方土壤氮素含量的影响远没有对北方旱地的影响那么明显,对我国北方土壤碱解氮含量的影响没有对全氮含量影响明显。 4.施肥对不同类型土壤氮素含量影响不同,北方土壤:施肥对塿土和潮土影响最明显,其次是灌漠土、褐土、灰漠土和公主岭黑土。南方土壤:施肥对水旱轮作的紫色土、黄棕壤的影响最明显,对红壤和水稻土的影响较小。 5.不同施肥处理下土壤全氮含量和碱解氮含量之间的相关关系均达到极显著正相关。土壤全氮含量每增加1.00 g·kg~/(-1/),北方土壤碱解氮含量在NPKS处理下增加量最低,仅为51.2 mg·kg~/(-1/),NPK处理下增加量最高,达到了107.7 mg·kg~/(-1/)。南方土壤碱解氮含量在单施氮肥处理时增加量最小,仅为57.3 mg·kg~/(-1/),其次是NPKS处理,NK处理增加量最大,达到了87.9 mg·kg~/(-1/)。 Statistical analysis on Nitrogen/(N/)contents and relevant data of Black soil, Gray desert soil, Fluvo-aquic soil, Irrigated desert soil, Black clay soil, Aquic soil, Lou soil, Red soil, Purple soil, Yellow brown soil and Paddy soil was conducted in order to understand the change in the N temporal evolution and spatial variability under the long-term fertilization, which could provide information for guiding the rational fertilization in future for the country. The main results were as follows: 1. Soil N content had different change with the time under long-term different fertilization. Soil total nitrogen /(STN/) content and soil alkali-hydrolyzable nitrogen /(SAN/) content of northern soil decreased significantly, with an average annual reduction of 0.009 g.kg~/(-1/) and 1.07 mg.kg~/(-1/) under no fertilization /(CK/) treatment; the long-term application increase NPK fertilizer + increase manure /(NPKM+/), the annual average increased 0.030 g.kg~/(-1/) and 2.33 mg.kg~/(-1/); the soil N contents of N, NP, NK, NPK, NPKM and NPKS treatments changed little. In Southern soil, under the CK, N, NK and NPKS treatments, STN decreased significantly, average annual decreased 0.017, 0.014, 0.015 and 0.029 g.kg~/(-1/); under NP, NPK, NPKM and NPKM+ treatments, STN changed little; SAN contents under CK, NP, NK and NPKS treatments also had remarkable declining trends, with average annual reduction of 1.43, 1.26, 2.10, and 3.13 mg.kg~/(-1/); But N, NPK, NPKM and the NPKM+ treatments, SAN contents changed little. Therefore, it can be inferred that no fertilizer will cause the decrease of soil N fertility, application of the chemical fertilizer and matched manure could maintain the soil N fertility, soil N content easily accumulated under high-nitrogen fertilizer and organic manure in northern soil; the soil N fertility decreased under partial N fertilizer and straw treatments, NPK fertilizer with organic fertilizer could maintain its N content stability in southern soil. 2. The soil N content was different under different applied fertilizer measure. Under NPKM+、NPKM and NPKS treatments, the STN average contents were higher 39.9/%, 26.9/% and 14.1/% than CK treatment’s, SAN average contents were higher 44.4/%, 32.8/% and 26.1/%; NPK treatment followed by 11.7/% and 14.3/% in northern soil. STN average contents of NPKM+ and NPKM treatments were higher 23.6/% than CK treatment’s, and SAN average content were higher 23.4/% and 21.0/%; NPK and NPKS treatments, STN average content were higher 14.6/% and 13.7/%; the SAN average content of NK treatment were higher14.6/% in southern soil. 3. Different fertilization treatments had different effect on the N content of different types of soil. The impact of fertilization to the N content of southern soil was less obvious than northern soil, to SAN was less than STN in northern soil. 4. The N content of different types of soil had been different affected by fertilization. In northern soil: fertilization had the significant effect on Aquic soil and Lou soil, followed by Irrigated desert soil, Gray desert soil, Fluvo-aquic soil and Black soil /(GZL/); in southern soil: fertilization had the significant effect on Water-Dry rotation of Purple soil and Yellow-brown soil, followed by Red soil and Paddy soil. 5. The correlation between STN content and SAN content were significant positive correlation under different fertilization. With the STN content increased 1.00 g.kg~/(-1/), the SAN of NPKS treatment increased to be lowest, was only 51.2 mg.kg~/(-1/), the NPK treatment increased highest, had achieved 107.7 mg.kg~/(-1/) in northern soil; the SAN content of N treatment increased to be smallest, was only 57.3 mg.kg~/(-1/), next was the NPKS treatment, the NK treatment with the largest increase, had achieved 87.9 mg.kg~/(-1/).

关 键 词： 长期施肥 土壤全氮 土壤碱解氮 典型土壤

分 类 号： [S158]

领　　域： [农业科学] [农业科学]