Topographic Influences on Soil Water and Spring Wheat Yields on Reclaimed Mineland
- S. A. Schroeder *
Topographic positions on undisturbed soils affect available soil water and crop yields. Reclaimed minelands are required by regulation to have productivity levels “equal to or greater than” premine levels. Since a normal reclamation technique is to place uniform depths of topsoil and subsoil across the topography, this technique often changes the topsoil and subsoil depths from the premine condition. The objective of this research was to determine if these changes in topsoil and subsoil depths have resulted in effects on soil water and crop yields unlike those documented for undisturbed soils. This study was initiated on reclaimed mineland in 1986 at two North Dakota coal mines where topographic positions (summit, shoulder, backslope, and footslope) were monitored for 6 yr for available water at planting, spring wheat (Triticum aestivum L.) yields, and soil water recharge from harvesting to planting the following year. Results showed that downslope topographic positions had nearly 300% more available soil water at planting (0- to 1.2-m depth due to greater recharge) and generally significantly greater (P = 0.10) spring wheat yields than upslope positions. Relationships between total water use and wheat yields were similar to those found for undisturbed soils. These results seem to suggest that the uniform depths of replaced topsoil and subsoil have not affected soil water and wheat yields differently on reclaimed minelands than on undisturbed landscapes in a semi-arid climate.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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