Pedosphere 31(5): 705--714, 2021
ISSN 1002-0160/CN 32-1315/P
©2021 Soil Science Society of China
Published by Elsevier B.V. and Science Press
| Field-scale spatial variability of soil calcium in a semi-arid region: Implications for soil erosion and site-specific management |
Yazhou SUN1, Wenxuan GUO1,2 , David C. WEINDORF3, Fujun SUN4, Sanjit DEB1, Guofeng CAO5, Jasmine NEUPANE1, Zhe LIN1, Abir RAIHAN1 |
1Department of Plant and Soil Science, Texas Tech University, Lubbock TX 79409 (USA);
2Department of Soil and Crop Sciences, Texas A&M AgriLife Research, Lubbock TX 79403 (USA);
3Department of Earth and Atmospheric Sciences, Central Michigan University, Mount Pleasant MI 48859 (USA);
4College of Land and Environment, Shenyang Agricultural University, Shenyang 110866 (China);
5Department of Geography, University of Colorado, Boulder CO 80309 (USA) |
| ABSTRACT |
| Excess calcium (Ca) in soils of semi-arid and arid regions has negative effects on soil structure and chemical properties, which limits the crop root growth as well as the availability of soil water and nutrients. Quantifying the spatial variability of soil Ca contents may reveal factors influencing soil erosion and provide a basis for site-specific soil and crop management in semi-arid regions. This study sought to assess the spatial variability of soil Ca in relation to topography, hydraulic attributes, and soil types for precision soil and crop management in a 194-ha production field in the Southern High Plains of Texas, USA. Soils at four depth increments (0–2, 0–15, 15–30, and 30–60 cm) were sampled at 232 points in the spring of 2017. The Ca content of each sample was determined with a DP-6000 Delta Premium portable X-ray fluorescence (PXRF) spectrometer. Elevation data was obtained using a real-time kinematic GPS receiver with centimeter-level accuracy. A digital elevation model (DEM) was derived from the elevation data, and topographic and hydraulic attributes were generated from this DEM. A generalized least-squares model was then developed to assess the relationship between soil Ca contents of the four layers and the topographic and hydraulic attributes. Results showed that topographic attributes, especially slope and elevation, had a significant effect on soil Ca content at different depths (P < 0.01). In addition, hydraulic attributes, especially flow length and sediment transport index (STI), had a significant effect on the spatial distribution of soil Ca. Spatial variability of soil Ca and its relationships with topographic and hydraulic attributes and soil types indicated that surface soil loss may occur due to water or wind erosion, especially on susceptible soils with high slopes. Therefore, this study suggests that the application of PXRF in assessing soil Ca content can potentially facilitate a new method for soil erosion evaluation in semi-arid lands. The results of this study provide valuable information for site-specific soil conservation and crop management. |
| Key Words: hydraulic attributes,portable X-ray fluorescence spectrometry,precision agriculture,soil conservation,topography |
| Citation: Sun Y, Guo W, Weindorf D C, Sun F, Deb S, Cao G, Neupane J, Lin Z, Raihan A. 2021. Field-scale spatial variability of soil calcium in a semi-arid region: Implications for soil erosion and site-specific management. Pedosphere. 31(5): 705–714. |
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