Freeze-thaw effects on phosphorus loss in runoff from manured and catch-cropped soils
Concern over nonpoint source P losses from agricultural lands to surface waters in frigid climates has focused attention on the role of freezing and thawing on P loss from catch crops (cover crops). This study evaluated the effect of freezing and thawing on the fate of P in bare soils, soils mixed w...
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Published in | Journal of environmental quality Vol. 34; no. 6; pp. 2301 - 2309 |
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Main Authors | , , , |
Format | Journal Article |
Language | English |
Published |
Madison
American Society of Agronomy, Crop Science Society of America, Soil Science Society
01.11.2005
Crop Science Society of America American Society of Agronomy |
Subjects | |
Online Access | Get full text |
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Summary: | Concern over nonpoint source P losses from agricultural lands to surface waters in frigid climates has focused attention on the role of freezing and thawing on P loss from catch crops (cover crops). This study evaluated the effect of freezing and thawing on the fate of P in bare soils, soils mixed with dairy manure, and soils with an established catch crop of annual ryegrass (Lolium multiflorum L.). Experiments were conducted to evaluate changes in P runoff from packed soil boxes (100 by 20 by 5 cm) and P leaching from intact soil columns (30 cm deep). Before freezing and thawing, total P (TP) in runoff from catch-cropped soils was lower than from manured and bare soils due to lower erosion. Repeated freezing and thawing significantly increased water-extractable P (WEP) from catch crop biomass and resulted in significantly elevated concentrations of dissolved P in runoff (9.7 mg L(-1)) compared with manured (0.18 mg L(-1)) and bare soils (0.14 mg L(-1)). Catch crop WEP was strongly correlated with the number of freeze-thaw cycles. Freezing and thawing did not change the WEP of soils mixed with manures, nor were differences observed in subsurface losses of P between catch-cropped and bare soils before or after manure application. This study illustrates the trade-offs of establishing catch crops in frigid climates, which can enhance P uptake by biomass and reduce erosion potential but increase dissolved P runoff. |
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Bibliography: | http://hdl.handle.net/10113/7275 ObjectType-Article-1 SourceType-Scholarly Journals-1 ObjectType-Feature-2 content type line 23 |
ISSN: | 0047-2425 1537-2537 |
DOI: | 10.2134/jeq2004.0415 |