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Sensitivity Analysis of the Parameters of a Mechanistic Mathematical Model Affected by Changing Soil Moisture 1
Author(s) -
Barber S. A.,
Mackay A. D.
Publication year - 1985
Publication title -
agronomy journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.752
H-Index - 131
eISSN - 1435-0645
pISSN - 0002-1962
DOI - 10.2134/agronj1985.00021962007700040006x
Subject(s) - moisture , nutrient , water content , agronomy , soil water , environmental science , chemistry , soil science , zoology , biology , geology , geotechnical engineering , organic chemistry
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, r o , and effective diffusion coefficient, D e , that resulted from changing the level of soil moisture (volumetric moisture contents of 0.22 ( M 0 ), 0.27 ( M 1 ), and 0.32 ( M 2 )) of three soils differing in available P and K. The data used were obtained in a controlled‐climate chamber study. Increases in D e , 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 M 0 to M 1 . 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 M 0 to M 1 . 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.