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Relationship between Soil Phosphorus and Phosphorus Budget in Grass Sward with Varying Nitrogen Applications
Author(s) -
Messiga Aimé Jean,
Ziadi Noura,
Bélanger Gilles,
Morel Christian
Publication year - 2014
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/sssaj2013.05.0200
Subject(s) - loam , phosphorus , human fertilization , zoology , nitrogen , agronomy , phleum , chemistry , soil water , environmental science , biology , soil science , organic chemistry
Changes in soil available P usually relate to P budgets, but the sensitivity of the relationship to N fertilization is poorly understood. Four P rates (0, 15, 30, and 45 kg ha −1 ) as main plots and four N rates (0, 60, 120, and 180 kg ha −1 ) as subplots were applied each year from 1999 to 2006 to a timothy ( Phleum pratense L.) sward established in 1998 on a gravelly sandy loam soil (Typic Fragihumods). Soil available P was assessed using water ( C p) and Mehlich‐3 (P M3 ) extractions. Annual P budgets were calculated as the difference between applied P and P offtake and were then summed over the duration of the experiment to determine the cumulative P budget (Bcum). Over the 8‐yr study, Bcum (−148 to 286 kg P ha −1 ), C p (0.13 to 0.94 mg L –1 ), and P M3 (22.3 to 111.7 mg kg −1 ) were affected by both P and N fertilization. The C p and P M3 were linearly related to Bcum and the relationship was similar among N rates [ Cp = 0.0016Bcum + 0.3 ( r 2 = 0.86, P < 0.001) and P M3 = 0.20Bcum + 47.7 ( r 2 = 0.90, P < 0.001)]. A positive or negative Bcum of 100 kg P ha −1 would then raise or deplete C p by 0.16 mg L –1 and P M3 by 20 mg kg −1 . The relationship between Bcum and soil available P was not affected by N applications in this gravelly sandy loam soil.