Dissertation > Excellent graduate degree dissertation topics show

Spatial Variability of the Concentrations of Available N,P and K in Soil on County Scales

Author: ZhangZuoZuo
Tutor: ZhouDaMai
School: Agricultural University of Hebei
Course: Plant Nutrition
Keywords: county cropland Nitrogen Phosphorous Potassium spatial variability balance ArcGIS grid calculation
CLC: S158
Type: Master's thesis
Year: 2013
Downloads: 57
Quote: 0
Read: Download Dissertation


Soil is fundamental material basis of human survival and development. Analysis ofthe spatial variation of soil characteristics can reveal the distribution of soil nutrients inspace effectively, providing a scientific basis for soil nutrient management. County is thebasic unit of the state administration. Available nitrogen, phosphorus and potassium in soilhas a very good characterization for the evaluation of soil fertility, in the study of soilspatial variability. The study of spatial variability of available nitrogen, phosphorus andpotassium and its balance has practical significance for formulate scientific fertilizationplan, improving the nutrient resource utilization and promoting development of the formulafertilization by soil test.However, traditional agricultural production hasn’t taken into account this spatialchangeability. In the same area the same quantities of fertilizer was applied to the wholefield, so the application of nitrogen, phosphorus and potassium fertilizers is much inappropriate. This traditional farming patterns lack direction, easily leading to nutrientimbalances and low utilization rate of fertilizer.In order to manage soil nutrients, taking Gaoyang County of Hebei Province as astudy area, geostatistics combined with GIS was applied to analyze the spatial structural,spatial distribution of soil nutrients in topsoil (0-20cm) in this area; grid calculation wasapplied to evaluate the balance of available N, P and K. The Spatial distribution maps ofavailable N, P and K content in cropland soil were produced by means of the universalKriging interpolation, it objectively reflected the abundance or deficiency of nutrients inthis study area. The evaluation map of AN, AP and AK balance was produced by gridcalculation. Results were as follows:1. In all the survey region, the average content of soil AN, AP and AK were71.30mg/kg、17.79mg/kg and126.15mg/kg, respectively. The content of soil AN and AK havehigh levels, AK have low levels. The coefficient of variation (CV) of AN, AP and AK were28.27%,81.06%and47.31%, belonged to moderate variability. These three availablenutrients took on normal distributions, which met the prerequisite for the study of spatialvariability of soil.2. Use the application of GS+software to make semi-variance analysis of nutrientdata and to obtain the theoretical model of each kind of soil nutrient. The best theoretical model of soil AN and AP was the exponential model, the best theoretical model of AK waslinear model. The C0/(C+C0) of AN was less than25%, had strong spatial self-correlations,structural factors were the main factors which affected the spatial variability of available Ncontents, the ranges of spatial dependence were16.21km. The C0/(C+C0) of AP contentwas between25%~75%, had moderates spatial self-correlations, the spatial variabilitywas caused by structural factors and random factors, and the range of spatial dependencewas21.57km. The C0/(C+C0) of AK content was more than75%, had weak spatialself-correlations, the spatial variability was caused by random factors, and the range ofspatial dependence was22.40km.3. The integrative comparisons of kriging prediction errors were carried out to fit thebest trend effect, the0-order trend effect was preferable. The Spatial distribution maps ofavailable N, P and K content in cropland soil were produced by means of the universalKriging interpolation, classified the data according to the abundance and deficiency’s indexof the concentrations of available nutrients. The concentration of AN was medium or high.The concentration of AP was low, the areas were less than25mg/kg AP accounted for91%of all the areas. The soil contained rather high AK, spatial distribution had no significantcharacteristics.4. The grid calculation was made to get evaluation map of nutrient balance, finallyapplied to evaluate the balance of AN, AP and AK. The evaluation map of nutrient balanceshowed that the areas of very imbalance, imbalance and balance accounted for40.46%,38.81%and20.73%of all the areas of investigative regions respectively. Theconcentrations of available N, P and K were high or medium in the balance areas. Thereare three balance conditions in plain areas, spatial distribution had no significantcharacteristics.

Related Dissertations

  1. Experimental Research on Influence of Coal Reburning Reaction Conditions on NO_x Reduction by Non-Catalytic Reduction of Ammonia,X701
  2. Research on Control of Precision Centrifuge Dynamic Balance System,TH113.25
  3. Development of Turbine Rotor Dynamic Balance System,TH877
  4. Financial Relations between the German government,F815.16
  5. Study on Rice-Frog and Melon-Frog-fish Ecological Cultivation and Breeding Mode and the Nutrient Balance,S-0
  6. Cultivation and Effects of Environmental Factors on Carrying WSSV Virus of Litopenaeus Vannamei,S945
  7. Coupled Dynamics of Excitable Systems Base on Morris-Lecar Model,Q42
  8. Effects of Light, Temperature and Nitrogen on the Growth of Three Kinds of Aquatic Plants,Q945
  9. Design, Synthesis and Antitumor Activities Study of Quinoxaline-1,4-dioxide Derivatives,R914
  10. Study on the Synthesis and Adsorption Behaviour of Chitosan Derivative,TS254.9
  11. Research on the Laws of Nitrogen and Phosphorus Loss and Control Scheme in Eryuan Rural,X712
  12. Risk Analysis and Mitigation Experiment of Heavy Metal Pollution in Croplands in Vicinity of Pollution Sources,X820.4
  13. Subarea Management of Tobacco Soil Nutrients and Adequate Fertilization Research by Micro Scale,S158
  14. Effects of Nitrogen Fertilizer on Morphological Development of Alfalfa Root,S541.9
  15. Effects of Water and Nitrogen Coupling on the Water and Nitrogen of Soil and Yield and Quality of Flue-cured Tobacco in Luzhou,S572
  16. Effect of Water and Nitrogen Coupling Using on Soil Physical and Chemical Properties in Tobacco Areas and the Yield and Quality of Fule-cured Tobacco in Yibin,S572
  17. Effects of the Nitrogen Management and Interactions with Leaf Number on Growth Yield and Quality of Burley Tobacco,S572
  18. Effects of N Addition on Soil Soluble Nitrogen and CH4 Oxidation of Upland in Subtropical,S714
  19. Influence of Biochar Amendments on Decomposition of Soil Organic Carbon and Morphology of Heavy Metal in Red Paddy Soil,S153.6
  20. The Effect of Nitrogen Phosphate and Potassium Proportion Fertilizers on Tea Tree Physiological Metabolism and Tea Quality,S571.1
  21. Optimization Design Andapplication of Extracting Methods of Maize (Zea Mays L.) Volatile Compounds,S513

CLC: > Agricultural Sciences > Agriculture as the foundation of science > Soil > Soil fertility (soil fertility )
© 2012 www.DissertationTopic.Net  Mobile