潮土有机碳库及肥力特性对长期施肥的响应

发布时间：2018-03-25 02:25

本文选题：潮土　切入点：长期施肥　出处：《山东农业大学》2017年博士论文

【摘要】：农田土壤有机碳是衡量土壤肥力高低的重要指标之一,也是土壤碳库中最活跃的部分。施肥是农田土壤有机碳库及肥力质量变化特征的重要影响因素,长期施肥下土壤有机碳库及肥力特性的变化研究对指导土壤可持续利用具有重要的科学意义。本文以潮土长期定位试验为研究平台,利用长期监测、室内培养、模型拟合和相关分析等相结合的方法,通过研究连续35年不施肥(CK)、单施氮肥(N)、施氮磷肥(NP)、施氮磷钾肥(NPK)、单施有机肥(M)、施氮肥和有机肥(MN),施氮磷肥和有机肥(MNP),施氮磷钾肥和有机肥(MNPK)等不同施肥潮土有机碳及其储量的演变规律,探讨长期不同施肥与有机碳储量的关系,利用生物学分组法分析长期化肥或有机肥施用后土壤有机碳转化及其组分的差异,揭示土壤有机碳与作物产量的关系,评价不同施肥下的培肥效果,以期为潮土地力提升、作物高产及农业固碳减排技术提供科学依据。主要研究结果与结论如下:(1)施肥处理均能显著提高潮土有机碳平均含量,以有机无机配施处理提高速率最为显著。连续施肥35年潮土有机碳储量增加了5.3-14.8 t C·hm-2,有机无机配施处理有机碳储量显著高于单施有机肥和施用化肥处理,单施有机肥处理显著高于施用化肥处理。当累积碳投入量大于83 t C·hm-2后,有机碳储量随外源有机碳投入量增加的幅度明显减缓,土壤固碳速率出现“饱和曲线效应”。土壤有机碳储量年均变化量与年均碳投入量符合线性正相关(y=0.0893x-0.0257 R2=0.9456,p0.01),要想维持该试验点初始有机碳水平年均最小碳投入量为0.29 t C·hm-2。(2)长期施肥(N处理除外)均可以显著提高潮土有机碳矿化速率及累积矿化量,以有机无机配施增加幅度最大(2.6-3.1倍)。土壤有机碳矿化速率变化均符合对数函数关系,且相关系数均达到极显著水平。采用三库一级动力学模型拟合表明,施肥增加中等活性有机碳库比例,降低惰性有机碳库比例,与CK处理相比,有机无机配施处理中等活性有机碳库含量增加幅度为12.0-12.5倍,远高于施用化肥处理(2.1-5.9倍)和单施有机肥处理(9.8倍);施用有机肥处理明显降低活性有机碳库周转时间。土壤有机碳各组分与碳投入量之间呈极显著正相关,以中等活性有机碳相关性最高。(3)施肥处理均极显著提高小麦和玉米平均产量,以有机无机配施增产效果最佳。施肥处理(N处理除外)均显著提高甘薯产量,以MNPK和NPK处理增幅最大,而MNPK和NPK处理间差异不显著。作物产量的稳定性和生产可持续性可分别用作物产量变异系数(CV)及可持续性产量指数(SYI)表征,有机肥配施氮磷钾肥的产量CV最低、SYI最高,土壤养分供应最为均衡,最有利于维持作物高产稳产。(4)土壤有机碳与作物产量状况密切相关,土壤有机碳含量与小麦、玉米和甘薯产量呈显著正相关,土壤活性、中等活性有机碳库含量与小麦和甘薯产量均呈显著正相关,土壤有机碳平均含量与小麦产量CV、SYI值相关性达到显著相关。(5)长期施肥对土壤肥力指标影响显著,施用有机肥处理显著降低土壤容重,而土壤孔隙度、有机质、全氮、碱解氮、全磷、有效磷、微生物生物量、过氧化氢酶、脲酶、碱性磷酸酶活性均显著增加。通过主成分分析可将原15个土壤指标降维,提取出2个主成分,反映了原信息量的85.51%。作为潮土肥力综合评价指标,生物指标中微生物生物量和过氧化氢酶优于脲酶、碱性磷酸酶和蔗糖酶;化学指标中土壤氮、磷元素和有机质起主导作用。采用主成分-聚类分析方法可将潮土肥力水平分为6个等级:一等为处理MNPK;二等为处理MNP;三等为处理M、MN;四等为处理NPK;五等为处理N、NP;六等为处理CK。
[Abstract]:Soil organic carbon is an important indicator of soil fertility, soil carbon pool is the most active part. Fertilization is an important factor affecting soil organic carbon and soil fertility quality change, change under long-term fertilization of soil organic carbon and soil fertility characteristics has important scientific significance for guiding the sustainable utilization of the soil in this paper. Based on the long-term soil test as the research platform, the use of long-term indoor monitoring, training method, model fitting and correlation analysis combined, through the study of 35 consecutive years without fertilization (CK), Dan Shidan (N), nitrogen fertilizer and phosphate fertilizer (NP), nitrogen phosphorus potassium fertilizer (NPK), single application organic fertilizer (M), nitrogen fertilizer and organic fertilizer (MN), nitrogen fertilizer and organic fertilizer (MNP), nitrogen phosphorus potassium fertilizer and organic fertilizer (MNPK) evolution of different fertilization soil organic carbon reserves and the effect of long-term different fertilization and organic carbon storage in turn System analysis of long-term chemical fertilizer or organic fertilizer after the transformation of soil organic carbon and its components by using the difference of biological grouping method, to reveal the relationship between soil organic carbon and crop yield, evaluation under different fertilization fertilizer effect, in order to enhance soil fertility, crop yield and agricultural carbon sequestration technology to provide a scientific basis. The results and conclusions are as follows: (1) fertilization could significantly increase the average organic carbon content in soil, organic and inorganic fertilizer treatment increased the rate of the most significant. 35 years continuous fertilization soil organic carbon reserves increased by 5.3-14.8 t C, hm-2, organic and inorganic fertilizer organic carbon storage was significantly higher than the single application of organic fertilizer and chemical fertilizer, organic fertilizer treatment was significantly higher than that of chemical fertilizer. When the cumulative carbon input is greater than 83 t C, hm-2, organic carbon storage with exogenous organic carbon inputs increased significantly slowed, soil Soil carbon sequestration rate of "saturation curve effect". The soil organic carbon storage annual variation and annual carbon inputs with a positive linear correlation (y=0.0893x-0.0257 R2=0.9456, P0.01), in order to maintain the initial level of organic carbon the minimum annual carbon amount was 0.29 t C hm-2. (2) long term fertilization (except for treatment N) could significantly improve the soil organic carbon mineralization rate and cumulative mineralization of organic and inorganic fertilizer, to increase the maximum (2.6-3.1 times). The changes of soil organic carbon mineralization rate were consistent with the logarithmic function, and the correlation coefficient reached significant level. By fitting a first-order kinetic model of three libraries showed that fertilization increased medium activity the proportion of organic carbon, reducing inert organic carbon ratio, compared with CK, the content of organic and inorganic fertilizer treatment medium active organic carbon pool increased by 12.0-12.5 times, far higher than the chemical fertilizer application (2.1-5 .9 times) and manure treatment (9.8 times); organic manure significantly reduced organic carbon turnover time. The activity between soil organic carbon fractions and carbon inputs were positively related to correlation between medium active organic carbon (3). The highest fertilization significantly high average yield of wheat. And corn, with organic and inorganic fertilizer production. The best fertilization treatments (except for treatment N) significantly increased the yield of sweet potato, with the largest MNPK and NPK increased, but there was no significant difference between MNPK and NPK treatments. The crop yield stability and sustainable production respectively by crop yield coefficient of variation (CV) and sustainability the yield index (SYI) characterization, organic fertilizer NPK fertilizer yield of CV was the lowest, the highest SYI, soil nutrient supply of the most balanced, the most conducive to maintain the stable yield. (4) the soil organic carbon and crop yield condition is closely related to soil organic The carbon content of wheat was significantly positively correlated, corn and sweet potato yield was positively related to the activity of soil, moderate labile organic carbon content and wheat and sweet potato yield was CV, the average content of soil organic carbon and wheat yield, SYI value was significantly correlated to. (5) effect of long-term application of fertilizers on soil fertility index significantly. Application of organic manure significantly reduced soil bulk density, soil porosity, organic matter, total nitrogen, available nitrogen, total phosphorus, available phosphorus, microbial biomass, catalase, urease, alkaline phosphatase activity increased significantly. Through principal component analysis, the original 15 soil index reduction, 2 principal components were extracted that reflects the original information of the 85.51%. as the tide soil fertility comprehensive evaluation index, microbial biomass and biological indicators is better than that of catalase urease, alkaline phosphatase and invertase; soil nitrogen chemical index, phosphorus and organic matter Taking the leading role. The principal component and cluster analysis method can be used to divide the fertility level of the fluvo aquic soil into 6 grades: one is to deal with MNPK, the other two is to deal with MNP, three is to deal with M, MN, four to deal with NPK, five to deal with N, NP, six and so on to deal with CK..

【学位授予单位】：山东农业大学
【学位级别】：博士
【学位授予年份】：2017
【分类号】：S153.6;S158

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