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Titolo:
PHOSPHORUS LEACHING FROM SOILS CONTAINING DIFFERENT PHOSPHORUS CONCENTRATIONS IN THE BROADBALK EXPERIMENT
Autore:
HECKRATH G; BROOKES PC; POULTON PR; GOULDING KWT;
Indirizzi:
INST ARABLE CROPS RES,ROTHAMSTED EXPTL STN HARPENDEN AL5 2JQ HERTS ENGLAND
Titolo Testata:
Journal of environmental quality
fascicolo: 5, volume: 24, anno: 1995,
pagine: 904 - 910
SICI:
0047-2425(1995)24:5<904:PLFSCD>2.0.ZU;2-Y
Fonte:
ISI
Lingua:
ENG
Soggetto:
NUTRIENT STATUS; PHOSPHATE; ENGLAND; WALES; PH;
Tipo documento:
Article
Natura:
Periodico
Settore Disciplinare:
Science Citation Index Expanded
Citazioni:
44
Recensione:
Indirizzi per estratti:
Citazione:
G. Heckrath et al., "PHOSPHORUS LEACHING FROM SOILS CONTAINING DIFFERENT PHOSPHORUS CONCENTRATIONS IN THE BROADBALK EXPERIMENT", Journal of environmental quality, 24(5), 1995, pp. 904-910

Abstract

Total P (TP), total particulate P (TPP), dissolved reactive P (DRP), and dissolved organic P (DOP) were determined in waters from pipe-drains (at 65-cm depth) from the Broadbalk Experiment at Rothamsted. Soilsthat have received either no P, P in farmyard manure (about 40 kg P ha(-1)) or superphosphate (up to 35 kg P ha(-1)) annually for >150 yr, now contain 0.5 M NaHCO3-extractable P concentrations (Olsen-P) in theplow layer (0- to 23-cm depth) between 5 and 100 mg kg(-1) soil. Our aim was to determine if significant quantities of P could be detected in the drainage water and their relationship to soil P concentrations. On five occasions between October 1992 and January 1994, both TP and DRP from plots receiving superphosphate frequently exceeded 1 mg L(-1)and were high compared with literature data. Ranging between 66 and 86% of TP, DRP was the largest fraction in drainage water. It remained low (<0.15 mg L(-1)) from plots below 60 mg Olsen-P kg(-1). There was then a rapid increase in DRP up to the maximum Olsen-P concentration. A simple linear Split-Line Model described this relationship very wellfor all drainage events. This implies that up to 60 mg Olsen-P kg(-1)soil (the change point), P was retained strongly in the plow layer. Above this, P losses in the drainage water were much more closely related to Olsen-P than commonly suggested. The mechanisms could either be preferential how or rapid transport of P in forms less susceptible to sorption but finally measured as DRP. The results suggest enhanced P losses through subsurface runoff on heavy soils, once a certain plow layer concentration of Olsen-P is exceeded.

ASDD Area Sistemi Dipartimentali e Documentali, Università di Bologna, Catalogo delle riviste ed altri periodici
Documento generato il 20/09/20 alle ore 19:56:38