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Phosphorus Diffusion in Soils: I. The Effect of Applied P, Clay Content, and Water Content
Author(s) -
Mahtab Samuel K.,
Godfrey Curtis L.,
Swoboda Allen R.,
Thomas Grant W.
Publication year - 1971
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/sssaj1971.03615995003500030021x
Subject(s) - soil water , loam , water content , chemistry , moisture , soil science , geology , geotechnical engineering , organic chemistry
Self‐diffusion coefficients of 32 P ( D ) were measured in four soils: Miller clay, Norwood loam, and two textural intergrades of these two soils. Clay percentages of the soils were: Norwood, 12.5; Intergrade I, 25.0; Intergrade II, 36.0; and Miller, 59.0. The P rates used were 0, 25, 50, and 100 ppm. The moisture levels were 35, 60, and 100% of the water content between ⅓ and 15 bars tension. The D values averaged over all clay and P levels, increased from 10.25 × 10 ‐10 to 27.76 × 10 ‐10 cm 2 /sec as the water content increased from 35 to 100% of the available moisture. The average D value increased from 5.05 × 10 ‐10 for the Norwood to 26.59 × 10 ‐10 cm 2 /sec for the Miller soil. Likewise, D values increased with increasing rates of added P for all soils. The data indicated reduction in available water has less effect on diffusion rates of P in clay soils than in the lighter‐textured soils. It follows that in order to maintain a given rate of diffusion in a soil, as water content decreases, the amount of added P must be increased.