长期施肥对黄土丘陵区农田土壤质量的影响

发布时间：2018-06-01 13:18

本文选题：黄土丘陵区 + 长期施肥　；参考：《西北农林科技大学》2016年博士论文

【摘要】：黄土丘陵区农田是我国北方农田的重要组成部分。为了增加作物产量,很多地方的肥料投入很大,不同施肥处理对土壤造成了不同程度的影响。为了明确这一区域施肥对土壤质量的影响,特以安塞站16年川地肥料长期定位试验为研究对象,对不同施肥处理下(N(氮肥)、P(磷肥)、NP、M(有机肥)、MN、MP、MNP、CK(对照)、BL(裸地))农田土壤性质进行综合分析,从土壤养分、土壤活性有机碳库以及影响养分转化、能量流动的微生物活性角度分析了这些指标对不同施肥处理的响应特征,进而通过相关分析、聚类分析、主成分分析等方法综合比较不同施肥处理的特点,主要得到以下结论:1.16年耕作后,相对于CK,长期施N肥、P肥和NP配施对有机质、全氮、碱解氮无显著性影响,含P肥的处理会显著增加土壤全磷和速效磷含量。有机肥参与的处理会显著增加土壤有机质、全氮、碱解氮和速效钾含量,较CK平均增加幅度分别为30%、31%、27%和85%。不同处理土壤下层(20-40cm)各养分的分异规律不如表层(0-20cm)明显。施肥主要影响土壤表层。2.不同施肥处理中,以MNP处理作物产量最高,随着施肥年限的增加,有机肥和化肥之间的产量差异越来越大。单施N肥或NP肥配施也可显著增加作物产量,而单施P肥增产效果并不显著。不同施肥处理对大豆、玉米不同部位N、P、K含量存在着显著差异。大豆籽粒N含量和P含量约为其茎荚的10倍。玉米籽粒中的N、P含量远远大于茎秆中的含量,而K含量远远小于茎秆含量,有机肥的处理会大量的增加玉米茎秆的K含量。3.不同施肥处理对土壤颗粒组成的影响差异并不显著,表层和下层土壤粘粒、粉粒、砂粒的百分含量平均为17.92%、60.72%、21.37%。土壤颗粒及微团聚体的优势粒级均为0.02~0.05mm。不同施肥处理土壤颗粒体积分形维数差异不显著,以MNP处理的值最小。土壤颗粒体积分形维数与粘粒(0.002mm)和细粉粒(0.002~0.02mm)极显著正相关,与粗粉粒(0.02~0.05mm)和细砂粒(0.05~0.2mm)极显著负相关;土壤团聚度与0.05mm各粒径土壤微团聚体显著负相关,与0.05mm各粒径土壤微团聚体显著正相关。4.相比于CK,有机肥比化肥处理更能提高土壤中水溶性有机碳(WSOC)、水溶性总氮(WSTN)含量,磷肥参与的处理会显著增加表层的水溶性总磷(WSTP)含量。长期施肥处理的表层土壤C/N值在10左右,下层为9,不同处理之间无显著差异,变异较小;而WSOC/WSTN则有显著变化,变化幅度在15.7-28.6之间,变幅较大,变异系数超过10%。WSOC对施肥措施的响应要比有机碳更为敏感。对照CK的土壤耕层有效Cu、Zn、Mn、Fe的含量分别为0.90、1.03、8.59、6.31mg kg-1,长期施用有机肥的土壤,土壤微量元素含量显著高于纯施化肥的土壤,对土壤有效锌、有效锰和有效铁的增幅作用都很显著,平均增幅分别达34.3%、31.5%和40.4%。长期氮肥处理,会造成土壤有效锌和有效锰的轻微亏损,但未达到显著性差异。黄土丘陵区农田土壤并不缺乏有效铜,而有效锌、有效锰和有效铁都处于亏缺边缘,施用有机肥可有效改善土壤中微量元素的贫瘠状况。水溶性有机物与微量元素中的有效锰、锌、铁极显著相关,有效铜只和水溶性有机碳显著相关。5.不同施肥处理的四个易氧化有机碳区组(F1,F2,F3和F4)的比例并不一样,按照F1F2F4F3的顺序排列,分别占总有机碳的47%,27%,18%,8%。有机肥处理能显著增加表层F1和F2组分,F3和F4组分则在下层土壤中无显著性变化。化肥处理则只能增加F4组分。有机肥处理的SOC,F1组分和F2组分的敏感性指数SI要比相应的化肥处理高,其中,F1组分比其他各组分更敏感,更适宜作为评价土壤碳组分变化的指标。6.除了过氧化氢酶外,脲酶、蔗糖酶和碱性磷酸酶酶活性都是表层高于下层;施化肥并不能显著影响土壤酶活性,有机肥参与的处理土壤酶活性要显著高于化肥处理,施肥方式的差异影响着土壤酶活性。单位有机碳酶活性的响应规律和传统酶活性的规律并不一致,大致上为有机质含量越高,其单位有机碳酶活性越低。脲酶、蔗糖酶和碱性磷酸酶活性的高低和有机碳的活性组分存在着极显著的相关性,有机碳组分中活性组分显著影响酶活性。单施氮肥能提高G-和总PLFA含量,单施磷肥能提高G-、放线菌和总PLFA含量;氮磷肥混施对微生物呼吸和群落结构的影响不明显。有机肥参与处理对G+、G-细菌、放线菌以及总PLFA含量都有显著影响。单施有机肥影响总PLFA含量和诱导呼吸,有机与无机肥混施能明显改变微生物群落结构和土壤呼吸强度;7.总计24个土壤指标经过主成分分析,可用4个主成分进行表征,可解释的累计方差为90%。4类主成分所表征的主要因子分别为碳氮因子、养分因子、磷因子以及土壤结构因子,方差贡献率依次为60.12%,17.15%,6.48%,6.29%。主成分分析结果表明,磷素是影响黄土区农田土壤质量的一个限制因素。农田中配施有机肥和磷肥,对土壤的综合质量提升最高。单施化肥或者只施化肥,会对土壤肥力造成损耗,不利于农业可持续发展,有机肥对于农田利用潜力的提升非常巨大。
[Abstract]:Farmland in the loess hilly region is an important part of farmland in the north of China. In order to increase crop yield, many places have a great input of fertilizer. Different fertilization treatments have caused different effects on soil. In order to clarify the effect of Fertilization on soil quality in this region, the long-term location test of fertilizer in Ansai station for 16 years was studied. A comprehensive analysis of soil properties of farmland under different fertilization treatments (N (nitrogen fertilizer), P (phosphorus fertilizer), NP, M (organic fertilizer), MN, MP, MNP, CK (control), BL (bare land)). The response characteristics of these indexes to different fertilization treatments were analyzed from soil nutrient, soil active organic carbon bank and influence of nutrient transformation and energy flow microbiological activity. By means of correlation analysis, cluster analysis and principal component analysis, the characteristics of different fertilization treatments were compared, and the following conclusions were obtained: after 1.16 years of tillage, compared with CK, N fertilizer had no significant effect on organic matter, total nitrogen and alkali nitrogen, and the treatment of P fertilizer could significantly increase the total phosphorus and available phosphorus content of soil. Organic fertilizer could be significantly increased by the treatment of P fertilizer. The content of soil organic matter, total nitrogen, alkali hydrolysable nitrogen and available potassium increased by 30%, 31%, 27% and 85%., respectively, which were 30%, 31%, 27% and 85%., respectively. The difference of different nutrients in the lower soil layer (20-40cm) was not as obvious as the surface layer (0-20cm). The yield difference between organic manure and chemical fertilizer is increasing with the increase of fertilization years. Single application of N fertilizer or NP fertilizer can also significantly increase crop yield, but the effect of single application of P fertilizer is not significant. The content of N, P and K in different parts of soybean and maize with different fertilization treatments is significantly different. The content of N and P in soybean grain is about its stem and the content of P is about its stem. The content of N and P in corn grain is much larger than that in stem, but the content of K is far less than the content of stem, and the treatment of organic fertilizer will increase the K content of corn stalk in a large amount.3.. The difference of soil particle composition is not significant in different fertilization treatments. The average content of clay, powder and sand in surface and lower layer soil is average to be 1. The 7.92%, 60.72%, 21.37%. soil particles and the dominant particle size of the micro aggregates are all 0.02~0.05mm. different fertilization treatment soil particle volume fractal dimension difference is not significant, MNP treatment value minimum. Soil particle volume fractal dimension and clay (0.002mm) and fine powder (0.002~0.02mm) very significant positive correlation, with coarse powder (0.02~0.05mm) and fine sand particles (0.05~0.2mm) significant negative correlation; soil aggregation was significantly negatively correlated with soil microaggregates of each particle size of 0.05mm. Compared with CK, the significant positive correlation of.4. to soil microaggregates of 0.05mm particles, organic manure could increase the water soluble organic carbon (WSOC), water soluble total nitrogen (WSTN) content in soil, and the treatment of phosphorus fertilizer participation would increase significantly. The content of water soluble total phosphorus (WSTP) in surface layer. The surface soil C/N value of the surface soil of long-term fertilization is about 10, the lower layer is 9, there is no significant difference between different treatments, and the variation of WSOC/WSTN has a significant change, the variation range is between 15.7-28.6, the amplitude is larger, and the variation coefficient over 10%.WSOC is more sensitive than the organic carbon. The content of effective Cu, Zn, Mn and Fe in the soil layer of CK was 0.90,1.03,8.59,6.31mg kg-1, and the soil microelement content was significantly higher than that of pure fertilizer. The increase of effective zinc, effective manganese and effective iron in soil was significant, the average increase was 34.3%, 31.5% and 40.4%., respectively. There is no significant difference in soil available zinc and effective manganese, but no significant difference is achieved. The farmland soil in the loess hilly region is not lacking in effective copper, while effective zinc, effective manganese and effective iron are on the margin of deficiency, and the application of organic fertilizer can effectively improve the poor condition of trace elements in the soil. The significant correlation of manganese, zinc and iron was significant, and the effective copper was significantly related to water soluble organic carbon (.5.). The proportion of four oxidizing organic carbon regions (F1, F2, F3 and F4) in different fertilizer treatments was different. According to the order of F1F2F4F3, the total organic carbon accounted for 47%, 27%, 18%, and 8%. organic fertilizer treatment could significantly increase the surface F1 and F2 components, F3 and F4 components. There is no significant change in the lower soil. The chemical fertilizer treatment can only increase the F4 component. The sensitivity index SI of the SOC, F1 component and F2 component of the organic fertilizer is higher than that of the corresponding fertilizer, and the F1 component is more sensitive than the other components, and it is more suitable to be used as an index for evaluating the change of soil carbon components,.6. except the catalase, urease, The activity of sucrase and alkaline phosphatase was higher than that in the lower layer. Fertilizer application did not significantly affect the activity of soil enzyme. The activity of soil enzyme in the treatment of soil by organic fertilizer was significantly higher than that of chemical fertilizer, and the difference of fertilization mode influenced the activity of soil enzyme. The response law of the activity of organic carbon enzyme was not consistent with the law of traditional enzyme activity. The higher the organic matter content, the lower the activity of organo carbonase. The activity of urease, invertase and alkaline phosphatase has a very significant correlation with the active components of organic carbon. The active components in the organic carbon component can significantly affect the activity of the enzyme. The single application of nitrogen fertilizer can increase the content of G- and total PLFA, and the single application of phosphate fertilizer can improve the G- and discharge line. The effect of organic manure on G+, G- bacteria, actinomycetes and total PLFA content had significant influence on the total PLFA content and the induced respiration, and the combination of organic and inorganic fertilizer could significantly change the microbial community structure and soil respiration intensity. 7. total 24 soil indexes can be characterized by 4 principal components. The explanatory cumulative variance is the main factor of 90%.4 principal component, namely, carbon and nitrogen, nutrient factor, phosphorus factor and soil structural factor, and the variance contribution rate is 60.12%, 17.15%, 6.48%. The results of 6.29%. principal component analysis show that Phosphorus is a limiting factor affecting the quality of soil in the loess region. The combination of organic manure and phosphate fertilizer in the farmland has the highest improvement in the comprehensive quality of the soil. Single fertilizer or only fertilizer can cause loss of soil fertility, which is not conducive to the sustainable development of agriculture, and the organic manure has greatly improved the potential of agricultural land use.
【学位授予单位】：西北农林科技大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：S158

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