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Project title

Eutrophication from Agriculture Sources - Phosphorus and Nitrogen

Primary Funding Agency

Environmental Protection Agency

Co-Funding Organisation(s)

n/a

Lead Organisation

Teagasc

Lead Applicant

Kim Reilly

Project Abstract

This document is a summary of the conclusions and recommendations that have been compiled from those listed in final reports submitted under LS-2.1 and LS-2.2 to date. Scientific conclusions have been compiled and integrated into recommendations that have implications for agriculture and water quality managers are based on scientific findings from the above research projects.ConclusionsThe conclusions (to date) from the research conducted in LS2.1 and LS2.2 fell broadly into the following categories; i land use i soil type i management i climate i catchment size and i modeling tools.Land Use The general conclusion from the catchment studies confirmed that managed grasslands are a significant source of nutrient loss to water (1.6-2.8 kgP/ha/yr). Other land use categories such as tillage and forestry were identified from a literature review. Soil TypeSoil type was shown to affect the drainage patterns and P chemistry of grassland soils and drainage class and chemical parameters such as %OM and pH influenced the quantity and quality of P exported in catchments. Saturation excess overland flow was identified as the dominant form of overland flow and the expanding variable source area (VSA) hydrology with freely desorbable P was responsible for the increase in P concentration with flow in overland flow.ManagementManagement factors affecting P loss to water identified in the research included the presence of grazing animals timing of slurry spreading fertilizer use and soil P levels. Grazing affected the quantity and quality of overland flow due to compaction and the presence of the grazing animal. Grazing animals and dung deposition affected cycling in grazed pastures and dung pats significantly increased soil test P levels and total inorganic P in soil. Fertiliser inputs and soil P levels in grazed pastures affected herbage P which in turn affected total P in dung and the distribution of soil P fractions such as water soluble P total inorganic and organic P.Fertiliser use on grassland farms matched advice given with fertilizer use on tillage systems greater than that advised. In general the higher the fertilizer P application rate the higher the potential for P loss to water. Fertiliser applications affected the complex interactions of soil nutrient that lead to a release of nutrients in overland flow.This document is a summary of the conclusions and recommendations that have been compiled from those listed in final reports submitted under LS-2.1 and LS-2.2 to date. Scientific conclusions have been compiled and integrated into recommendations that have implications for agriculture and water quality managers are based on scientific findings from the above research projects.ConclusionsThe conclusions (to date) from the research conducted in LS2.1 and LS2.2 fell broadly into the following categories; i land use i soil type i management i climate i catchment size and i modeling tools.Land Use The general conclusion from the catchment studies confirmed that managed grasslands are a significant source of nutrient loss to water (1.6-2.8 kgP/ha/yr). Other land use categories such as tillage and forestry were identified from a literature review. Soil TypeSoil type was shown to affect the drainage patterns and P chemistry of grassland soils and drainage class and chemical parameters such as %OM and pH influenced the quantity and quality of P exported in catchments. Saturation excess overland flow was identified as the dominant form of overland flow and the expanding variable source area (VSA) hydrology with freely desorbable P was responsible for the increase in P concentration with flow in overland flow.ManagementManagement factors affecting P loss to water identified in the research included the presence of grazing animals timing of slurry spreading fertilizer use and soil P levels. Grazing affected the quantity and quality of overland flow due to compaction and the presence of the grazing animal. Grazing animals and dung deposition affected cycling in grazed pastures and dung pats significantly increased soil test P levels and total inorganic P in soil. Fertiliser inputs and soil P levels in grazed pastures affected herbage P which in turn affected total P in dung and the distribution of soil P fractions such as water soluble P total inorganic and organic P.Fertiliser use on grassland farms matched advice given with fertilizer use on tillage systems greater than that advised. In general the higher the fertilizer P application rate the higher the potential for P loss to water. Fertiliser applications affected the complex interactions of soil nutrient that lead to a release of nutrients in overland flow.

Grant Approved

�99,245.00

Research Hub

Natural Environment

Research Theme

Improve our Knowledge on the State of our Water Resources and Pressures

Start Date

01/11/2000

Initial Projected Completion Date

n/a