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Modeling Potassium Uptake by Slash Pine Seedlings from Low‐Potassium‐Supplying Soils
Author(s) -
Van Rees K. C. J.,
Comerford N. B.,
McFee W. W.
Publication year - 1990
Publication title -
soil science society of america journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.836
H-Index - 168
eISSN - 1435-0661
pISSN - 0361-5995
DOI - 10.2136/sssaj1990.03615995005400050034x
Subject(s) - slash pine , soil water , potassium , greenhouse , environmental science , agronomy , chemistry , pinus <genus> , slash (logging) , nutrient , horticulture , botany , soil science , biology , ecology , organic chemistry
The application of diffusion/mass‐flow theory to K uptake by slash pine ( Pinus elliottii Engelm. var. elliottii ) seedlings from low‐K‐supplying soils is presented. Simulations for K uptake were evaluated by the Barber‐Cushman model (BCM) and the Baldwin‐Nye‐Tinker model (BNTM) under greenhouse and field conditions. Potassium uptake was overpredicted by 31 to 50% in greenhouse studies; overestimates, however, are attributed to nonuniform distribution of roots along pot walls. Simulations underpredicted K uptake by 0.48 and 0.83 times that observed in seedlings grown in the field. Although ectomycorrhizal hyphae were abundant in the field, their contribution to K uptake was not incorporated. Predictions of K uptake were excellent for seedlings grown at a tree nursery when fertilizer amendments were included. The BNTM, based on simplifying assumptions, predicted K‐uptake values similar to the BCM. Sensitivity analysis showed that root growth and initial K concentration in soil solution were the two most important factors affecting K uptake by slash pine. Soil processes that control K concentration were the limiting factors to K uptake on these soils. Monte Carlo procedures indicated that, for two harvests in the field, simulated estimates of uptake had CVs ranging from 34 to 64%.