Extrinsic spatial variability of selected macronutrients in a sandy soil
Document Type
Article
Publication Date
1-1-1994
Abstract
In addition to native or intrinsic variability, the spatial variability of a soil property at a managed site includes an extrinsic component which is due to management practices. The objective of this study was to estimate changes in the extrinsic spatial variability of Ca, Mg, K, and P in the surface soil which resulted from tillage and fertilizer application. Such changes may increase or decrease total variability. The upper 15 cm of soil from a small experimental field (0.31 ha) on Millhopper fine sand (loamy, siliceous, hyperthermic, Grossarenic Paleudult) was sampled with a large bore soil probe. Soil samples were taken before and after plowing and application of mixed fertilizers. Average contents of these elements for subareas of the field were estimated using block kriging techniques. Comparisons of block-kriged estimates for Ca, Mg, K, and P before and after tillage and fertilizer application were used to assess the extrinsic spatial variability of these elements. Results of this study indicated that both tillage and fertilizer application altered the spatial distribution of these macronutrients. Attempted uniform site preparation for planting resulted, therefore, in nonuniform changes in extractable Ca, Mg, K, and P. Those elements which were applied at high rates exhibited large increases in variability and marked changes in distribution patterns. Knowledge of the pre-plant spatial variability and distribution of nutrient elements may aid in the planning and execution of field experiments or serve as a basis for soil specific crop management practices. © 1994.
Publication Source (Journal or Book title)
Geoderma
First Page
95
Last Page
106
Recommended Citation
Nkedi-Kizza, P., Gaston, L., & Selim, H. (1994). Extrinsic spatial variability of selected macronutrients in a sandy soil. Geoderma, 63 (1), 95-106. https://doi.org/10.1016/0016-7061(94)90112-0