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Abstract:This paper took the wheat field of typical alluvial soil area as the research site, aimed to explore the spatial pattern of the soil nutrients, such as soil available potassium, soil available phosphorus, soil organic matter (SOM) and soil alkali hydrolysable nitrogen. With the help of DGPS, a total of 104 topsoil(0-20cm) samples were collected. Based on classical statistics, research results indicated the average content of soil available potassium was 287.476g/kg, the high value was 483.433g/kg, the low value was 119.435g/kg. The average content the low value was 18.77g/kg. The average content of SOM was 36.901g/kg, the high value was 47.420g/kg, the low value was 21.110g/kg. The average content of soil alkali hydrolysable nitrogen was 66.444g/kg, the high value was 166.474g/kg, the low value was 29.846g/kg. Geostatistical analysis, sill of soil nutrients characteristics were calculated, semivariogram model was established, ordinary kriging was applied, and the spatial distributing map of soil nutrients was drawn. It is shown that the semivariogram structures of the respectively, which belonged to the middle intensity, the ratio of nugget/sill of Spatial variation of soil available potassium was mainly caused by structural factors(parent material, terrain, climate, water table etc.), the structure variability of it took 60.1% of the total variability, the spatial variation of soil available phosphorus, SOM and soil alkaline hydrolysis nitrogen were mainly caused by random factors(fertilization, environmental pollution, cultivation measures, management etc.), the random variability of them took 75.9%, 74.6%, 69.6% of the total variability, respectively, the spatial correlation Please use the following format when citing this chapter:of soil available phosphorus was 54.228g/kg, the high value was 293.13g/kg, combined with geographical information system(GIS), the range, nugget and Z. Chunjiang, (Boston: Springer), pp. 125-134.

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To advance site-specific management of soil volumetric moisture content (VMC), this study analyzed the spatio-temporal evolution characteristics of soil VMC using the method of sequential Gaussian simulation (SGS) during the different growth stages of winter wheat. This was compared with data measured by time domain reflectometry (TDR) which is a well-established electromagnetic technique to measure soil VMC. The spatial autocorrelation coefficient of VMC indicated the strongest clustering of VMC in the tillering stage, and the least clustering of VMC in the harvest stage. A threshold of VMC in topsoil in the jointing stage of winter wheat was put forward. This threshold is 26, signifying that at a lower value, irrigation should be performed and irrigation efficiencies can be improved. Stable and sub-stable areas in the spatial variability maps of VMC were identified in the winter wheat jointing stage. Furthermore, the optimal irrigation stage was the early jointing stage, and irrigation was performed once as a guide. A loose-couple spatial model was constructed using the VMC in topsoil and the volume of water for irrigation. The VMC in the jointing stage of winter wheat was linked with efficient and water-saving irrigation.

Understanding and quantitative delineation of Portable X-Ray Fluorescence (PXRF)-quantified elements and soil properties spatial variability are important for healthy turf development for golf courses. In this study, PXRF-quantified elements and soil properties (except soil acidity and alkalinity (pH), electric conductivity (EC), and textures) of 200 soil samples were measured by PXRF analyzer at different golf courses in Lubbock, Amarillo, and Midland in Texas, and Hobbs in New Mexico. Furthermore, principal component analysis (PCA), empirical bayesian kriging (EBK) and the ordinary least square model (OLSM) were used in the study. Two kinds of components were extracted and interpreted by PCA, the results showed Zn, Ti, Fe, Rb, V, Mn and Zr were associated with the component 1, while Sr was associated with the component 2, the preliminary classification of PXRF-quantified elements was formed by PCA. The EBK approach was used to evaluate the spatial patterns of PXRFquantified elements and soil properties. The OLSM model quantitatively related pH to EC, silt texture and the PXRF-quantified K, Ca and Sr. The integration of PCA, EBK and OLSM revealed quantitative links between soil pedogenesis and causes, spatial variability and couple relationships of PXRFquantified elements and soil properties over golf courses. Currently, proximal soil sensing presents the characteristics of interdisciplinary with pedometrics, pedology and morphology. Proximal and remote sensing, along with miniaturized sensor technology, have advanced the useful non-destructive monitoring technologies for rapidly quantifying heavy metal concentrations. The Portable X-ray Fluorescence (PXRF) spectrometry is a proximal scanning technology and has a long history of being used in characterizing the elemental compositions in many matrices 1,2. The PXRF technology can be implemented in soil geochemical analysis for fast and efficient testing of heavy metals 3 , and used to answer the questions of direct soil provenance based on the understanding that both soil pedogenesis with climate, parent material, topography and other factors 4. Applications of PXRF included environmental assessment and identification of heavy metal concentrations of soils, compost, or solid waste 5-7. PXRF applications to pedology were rapidly increasing given the relative ease of data acquisition 8. The PXRF's ability to predict soil textural attributes was demonstrated, which is of interest in texture related to mineral composition 7. PXRF was valid as well to rapidly screen Cr and Ni levels in serpentine soils 3. Laiho and Perämäki (2005) found that soil moisture and particle size were the main factors influencing on PXRF measurement accuracy from contaminated site soils 9. The response of X-ray fluorescence (XRF) intensity to soil moisture content depended on soil texture and mineralogy 10 , however, it is generally stable in measuring soil elements when moisture content is <15% 8,11. Over the past 10 years, PXRF has been much more used in soil science. Among many contempora...