Sensitivity Analysis of the Parameters of a Mechanistic Mathematical Model Affected by Changing Soil Moisture1
- S. A. Barber and
- A. D. Mackay2
Sensitivity analyses are useful for evaluating the effects of changes in soil and plant properties on plant nutrient uptake. The objective of this study with corn (Zea mays L.) was to determine the influence on P and K uptake of changes in root growth rate, k, mean root radius, ro, and effective diffusion coefficient, De, that resulted from changing the level of soil moisture (volumetric moisture contents of 0.22 (M0), 0.27 (M1), and 0.32 (M2)) of three soils differing in available P and K. The data used were obtained in a controlled-climate chamber study. Increases in De, which resulted from raising soil moisture, only explained 27 to 32% and 11 to 27% of the total calculated increase in P and K uptake, respectively, across the three soils as moisture was raised from M0 to M1. In contrast, the increase in k, which resulted from raising soil moisture, explained 50 to 56% and 46 to 69% of the total calculated increase in P and K uptake, respectively, as moisture was raised from M0 to M1. This emphasized the importance of root growth in providing the plant with an adequate supply of nutrients. The results highlight the significance of soil moisture in plant growth and demonstrate the advantages of using the modeling approach to furnish data on the effects of moisture on each of the mechanisms involved in nutrient uptake.Please view the pdf by using the Full Text (PDF) link under 'View' to the left.
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