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Evaluation of Soil Testing Methods for Predicting Growth and Response of Pinus elliottii to Phosphorus Fertilization
Author(s) -
Ballard R.,
Pritchett W. L.
Publication year - 1975
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/sssaj1975.03615995003900010034x
Subject(s) - human fertilization , sowing , pinus <genus> , phosphorus , greenhouse , soil water , field experiment , zoology , soil test , agronomy , chemistry , horticulture , botany , biology , ecology , organic chemistry
Soil tests were evaluated as methods for predicting height growth or increased height growth due to P fertilization of Pinus elliottii var. elliottii Engelm. on acid Coastal Plain soils. Growth and response parameters were obtained from field and greenhouse trials fertilized at time of planting with N and P. Field trials were measured 1, 3, and 5 years after planting and the greenhouse trial, which involved unfertilized soils collected from the field trials, was measured 1 and 2 years after planting. The amounts of P extracted by H 2 O or NH 4 OAc (pH 4.8) were the most closely correlated with height growth and response to P fertilization after 1 year of growth in both the greenhouse and field. The effectiveness of these methods declined after longer growth periods. Methods which extracted larger amounts of P—0.5 M NaHCO 3 ; 0.05 N HCl + 0.025 N H 2 SO 4 ; 0.03 N NH 4 F + 0.025 N HCl—were more effective predictors of response to P fertilization over growth periods of 3 and 5 years in the field. Phosphorus extracted by 0.03 N NH 4 F + 0.025 N HCl was the most closely correlated with response recorded after 5 years ( r 2 = 0.778). Concentrations of P in the tops of greenhouse‐grown pine seedlings after both 1 and 2 years growth were most closely related to P removed by the stronger extractants. The r 2 values for the relationships between soil test values and both concentrations of P in seedling tops after 2 years and in foliage of field trees at age 4 were almost identical.