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Differential Phosphorus Retention in Soil Profiles under No‐Till Crop Production
Author(s) -
Guertal E. A.,
Eckert D. J.,
Traina S. J.,
Logan T. J.
Publication year - 1991
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/sssaj1991.03615995005500020020x
Subject(s) - loam , soil water , sorption , plough , chemistry , extraction (chemistry) , tillage , soil science , silt , soil horizon , soil test , phosphorus , agronomy , environmental science , adsorption , geology , chromatography , paleontology , organic chemistry , biology
Field trials in Ohio have shown that the Bray‐1 P soil‐test level for optimum corn ( Zea mays L.) production is greater for no‐till than for conventionally (moldboard plow) tilled corn. Studies using Hoytville silty clay loam (fine, illitic, mesic Mollic Ochraqualf) and Canfield silt loam (fine‐loamy, mixed, mesic Aquic Fragiudalf) taken from long‐term no‐tillage plots indicated decreased retention of P against the Bray‐1 extractant in surface soils, compared with samples from deeper within the soil profile. In an effort to further examine the P‐retention characteristics of no‐till soil profiles, experiments were prepared using P‐sorption isotherms, before and after a series of sequential anion resion extractions. Prior to sequential extractions, the isotherms showed decreased sorption of P at the soil surface (0–2 cm), compared with deeper soil layers. Resin extraction removed more P from surface layers than deeper depths, and the quantity of P removed with each extraction declined much more quickly in the surface layers than in lower depths. After resin extraction there was a trend for greater retention of P against the Bray‐1 extractant in the upper soil layers. Sorption isotherms created after resin extraction show increased P sorption at all depths and closer agreement between the shape of the isotherm curves. It appears that accumulated P on the soil surface saturates P fixation sites, resulting in differential retention of P with depth.