【作者】 解丽娟；

【导师】 王伯仁； 徐明岗；

【作者基本信息】 中国农业科学院 ， 土壤学， 2011， 硕士

【摘要】 为了探明我国典型农田土壤长期不同施肥下有机碳与全氮的剖面分布特征,本研究以五种不同气候区典型农田土壤(黑土、灰漠土、塿土、红壤、潮土)进行不同施肥长期定位试验,监测分析了1m深剖面包括五个层次的土壤有机碳与全氮含量,并系统总结了有机碳与全氮的时间、空间分布特征,为我国土壤肥力提升、农业可持续发展提高理论依据。主要结果与结论如下:(1)在不同土壤中随着土壤深度的增加土壤有机碳不断降低,在40-100cm土层之间降幅逐渐减小。黑土有机无机配施处理(NPKM、NPKM2)的0-40cm土层有机碳含量在施肥年限内表现为在后十年增高趋势;塿土与灰漠土在施肥年限内有机肥配施化肥处理的0-40cm土壤有机碳含量随着施肥年限的增长而增加。在0-40cm内,所有土壤类型的系统碳投入量与有机碳变化量呈显著的正相关关系,且有机肥的固碳效率大于秸秆还田处理。施肥20年后,与CK相比, NPKM、NPKM2均可提高土壤0-40cm有机碳含量,但增幅差异较大,其中在0-20cm土层中NPKM、NPKM2处理有机碳增幅分别达到29.0%-109.7%和49.4%-183.1%,它们在不同土壤的增幅表现为从西到东、从南到北依次增幅依次变大,即灰漠土>塿土>红壤>潮土>黑土,NPKM2还提高了灰漠土、塿土、潮土40-60cm的有机碳含量。NPKS除黑土外其余土壤均提高了0-20cm有机碳含量,增幅在21.9%-69.1%,它们在不同土壤的增幅表现为塿土>潮土>红壤>灰漠土,NPKS还提高了黑土、塿土、潮土20-40cm的有机碳,增幅为18.8%-63.1%。CK0处理0-20cm土壤有机碳均显著增加,增幅为20.8%-55.7%,它们在不同土壤的增幅为红壤>塿土>灰漠土>潮土>黑土,CK0还提高了塿土20-40cm与红壤20-60cm的有机碳。长期施用化肥(N、NK、PK)不利于有机碳的增加,其余施用化肥处理(NPK、NP)处理可以提高塿土、红壤、潮土的0-20cm有机碳含量,增幅在21.3%-33.8%。(2)在不同土壤中随着土壤深度的增加土壤全氮不断降低,在40-100cm土层之间降幅逐渐减小。全氮含量随时间的变化与有机碳变化相似。施肥20年后,与CK相比,NPKM、NPKM2均可以显著提高土壤0-40cm全氮含量,0-20cm常量与高量增幅分别为32.0%-106.2%与54.7%-206.3%,它们在不同土壤的增幅表现为灰漠土>塿土>潮土>红壤>黑土;20-40cm常量与高量增幅分别为15.0%-143.6%与33.6%-306.3%,它们在不同土壤中的增幅表现为灰漠土>黑土>潮土>红壤>塿土。由于氮素淋溶作用,20-100cm土层中,黑土、塿土、红壤、潮土所有处理全氮均有不同程度提高,但增幅小于0-40cm。(3)施肥11(12)年后,与CK相比,黑土、塿土碳氮比(C/N)无明显变化,灰漠土不同处理碳氮比有升有降,未表现出规律性变化。在施肥20年年限内,黑土、塿土随着施肥年限的增加土壤C/N提高,灰漠土随着施肥年限的增加C/N降低。所有土壤的C/N在0-80cm内随着土壤深度的增加而降低,80-100cm与60-80cm相比又有所升高。施肥20年后黑土、灰漠土C/N无显著性变化。与CK相比氮肥(N)与氮钾(NK)降低了塿土与红壤的0-20cm土壤C/N,其余处理耕层均有所升高。NPKM2提高了潮土中耕层C/N。各土壤耕层C/N在8.72-11.0,它们在不同土壤中的碳氮比表现为潮土>黑土>灰漠土>塿土>红壤。更多还原

【Abstract】 In order to investigate profile distribution feature of organic carbon and total nitrogen in typical cropland of China under various kinds of long-term fertilization, black soil, grey desert soil, lou soil, red soil and fluvo-aquic soil were collected from different cropland of climatic region. Organic carbon and total nitrogen content in different five levels of soil profile with depth of 0-100cm were analyzed and characteristic of temporal and spatial distribution of organic carbon and total nitrogen was also summarized systemically, as provides important theoretical basis for soil fertility enhancement and sustainable agricultural development in China. The main results and conclusions were listed as follows.(1)Soil carbon content decreased gradually with increase of soil depth in various soil, and the magnitude of decrease in soil layers with depth of 40-100cm turn out to be less. Through the application of NPKM or NPKM2, organic carbon content in black soil with depth of 0-40cm showed a increasing trend in the last decade during fertilization age, while organic carbon content in lou soil and grey desert soil with the same depth range increased year by year during fertilization age. In all kinds of soil with depth of 0-40cm, carbon inputs were positively correlated to changes of organic carbon content in soil, and the carbon sequestration efficiency of organic fertilizer was greater than the straw treatment.After 20 years of fertilization, in contrast to CK, application of NPKM and NPKM2 can both increase organic carbon content with soil depth of 0-40cm, but the amplitudes of carbon content were changed in difference. In the soil with depth of 0-20cm, application of NPKM and NPKM2 increased the organic carbon content by 29.0%-109.7% and 49.4%-183.1% respectively. The amplitudes of carbon content showed a increasing trend in various soil from the west to the east and from the south to the north in China, or were in an order of grey desert soil>lou soil>red soil> fluvo-aquic soil>black soil. Application of NPKM2 also increased organic carbon content in grey desert soil, lou soil and fluvo-aquic soil with soil depth of 40-60cm. Application of NPKS increased organic carbon content in various soils except black soil with depth of 0-20cm. The amplitudes of carbon content were 21.9% -69.1%, and were in an order of lou soil>fluvo-aquic soil>red soil>grey desert soil. Application of NPKS also increased organic carbon content in black soil, lou soil and fluvo-aquic soil with depth of 20-40cm, and the amplitudes of carbon content were 18.8%-63.1%. CK0 treatment can increase organic carbon content significantly in soil with depth of 0-20cm, and the amplitudes of carbon content were 20.8%-55.7%, and the amplitudes were in an order of red soil>lou soil>grey desert soil> fluvo-aquic soil>black soil. CK0 treatment also increased organic carbon content in lou soil with depth of 20-40cm and red soil with depth of 20-60cm. Long-term application of N, NK and PK was not helpful to increase of carbon content in soil, but NPK and NP can improve carbon content in lou soil, red soil, and fluvo-aquic soil with depth of 0-20cm, and the amplitudes were 21.3%-33.8%.(2) Total nitrogen in various kinds of soil decrease gradually with increase of soil depth, and the magnitude of decrease in soil layers with depth of 40-100cm turn out to be less. The change of total nitrogen with fertilization age is similar to that of organic carbon content in soil. After 20 years of fertilization, Application of chemical fertilizers combined with manure(NPKM, NPKM2)can increase total nitrogen content with soil depth of 0-40cm remarkably. Application of NPKM and NPKM2 can increase carbon content with soil depth of 0-20cm by 32.0%-106.2% and 54.7%-206.3% respectively, and the amplitudes of carbon content in different soil were in an order of grey desert soil > lou soil > fluvo-aquic soil > red soil > black soil. The treatments of NPKM and NPKM2 can improve carbon content with soil depth of 20-40cm by 15.0%-143.6% and 33.6%-306.3% respectively, and the amplitudes of carbon content in different soil were in an order of grey desert soil > black soil > fluvo-aquic soil > red soil > lou soil. Due to nitrogen leaching, total nitrogen content in soil layers with depth of 20-100cm was improved differently by all treatments in black soil, lou soil, red soil and fluvo-aquic soil, but the increase amplitudes were lower than those in soil layers with depth of 0-40cm.(3) After 11 or 12 years of fertilization, carbon and nitrogen ratio (C/N) showed no obvious change in black soil and lou soil in contrast to control treatment (CK). Different treatments resulted in changes of C/N in grey desert soil, including rise and fall, therefore C/N in grey desert soil showed no regular change.During 20 years of fertilization, C/N in black soil and lou soil increased year by year with increasing fertilization age, but C/N in grey desert soil decreased gradually with increasing fertilization age. C/N in all soil decreased with increased soil depth among 0cm and 80cm, but surprisingly, C/N in soil with depth of 80-100cm was higher than that in soil with depth of 60-80cm. After 20 years of fertilization, C/N in black soil and grey desert soil showed no notable change. Compared with control treatment (CK), the treatments of N and NK decreased C/N in lou soil and red soil with depth of 0-20cm, but other treatments increased C/N in soil. Application of chemical fertilizers combined with manure (NPKM2) increased C/N in soil layers of fluvo-aquie soil. C/N in different soil layers was between 8.72 and 11.0, and the C/N in different soil were in an order of fluvo-aquic soil > black soil > grey desert soil > lou soil > red soil.更多还原