Document Type
Article
Publication Date
5-2020
Keywords
distillation; rice
Abstract
The Nitrogen-Soil Test for Rice (N-STaR) provides a site-specific N rate recommendation by quantifying alkaline hydrolyzable-N (AH-N). A user-friendly method for obtaining a representative N-STaR soil sample is needed, and this study was designed to evaluate the performance of alternative sampling techniques compared with the Dutch auger (DA). The alternative techniques included a Kleen Hole Spade dry (KHS-D), a KHS lubricated with water (KHS-W), a KHS lubricated with WD-40 (KHS-40), and the N-STaR Bucket and Drill (BD). One soil sample was collected with each sampling technique from four blocks and was repeated across 14 sites. Each sample was analyzed for AH-N using N-STaR and compared against the DA. Variability in AH-N ranged from a coefficient of variation (CV) of 4.4% at Site 3 to 22.3% at Site 5. The AH-N at 13 of the 14 sites had no significant differences among sampling techniques. At Site 14, the AH-N measured using the KHS-40 was statistically higher than the DA by 25 mg AH-N kg soil(-1) and would correspond to a fertilizer N rate difference of 49 kg N ha(-1). The KHS-D probe appears to have the greatest accuracy and precision compared to the DA, although the KHS-W, KHS-40, and the BD produce similar results. All alternative techniques averaged a numerically higher AH-N value than the DA but were not statistically different for 55 of the 56 observations. Therefore, these alternative soil sampling methods can be used successfully to collect soil samples for N-STaR analysis on clayey soils.
Citation
Davidson, J. T., Roberts, T. L., Hardke, J. T., Slaton, N. A., & Fulford, A. M. (2020). Comparison of Soil Sampling Techniques for Alkaline Hydrolyzable-nitrogen on Clay Soils. Agrosystems Geosciences & Environment, 3 (1) https://doi.org/10.1002/agg2.20046
Creative Commons License
This work is licensed under a Creative Commons Attribution 4.0 International License.
