The impact of grazing cattle on soil physical properties and nutrient concentrations in overland flow from pasture, Part B

This report has been prepared as part of the Environmental Research Technological Development and Innovation Programme 2000–2006. The programme is financed by the Irish Government under the National Development Plan 2000–2006.End of project reportThe loss of nutrients from agricultural land to water bodies is a serious concern in many countries. To gain information on the contribution of grazing animals to diffuse nutrient losses from pasture areas to water, this study looked at the impact of cattle on nutrient concentrations in overland flow and on soil hydrology (bulk density, macroporosity and resistance to penetration). Rainfall simulations to produce overland flow were conducted and soil physical measurements were taken on experimental plots assigned to one of two treatments: 1) cattle had unrestricted access to the plot; 2) cattle could graze the plot but they could neither walk on the plot area nor deposit excrements on it. Areas to which the cattle had free access were characterised by 57%-83% lower macroporosity, by 8%-17% higher bulk density and by 27%-50% higher resistance to penetration than areas from which the cattle were excluded. The nutrients in overland flow from grassland that were affected by the presence of grazing animals were mainly the particulate nitrogen, the organic phosphorus and the potassium concentrations. Overall, the presence of cattle had a longer lasting effect on the soil hydrological parameters measured than on the nutrient concentrations in overland flow.Environmental Protection Agenc

Soil Analysis and Comparison of Soil Phosphorus Tests for the Bellsgrove Catchement, Cavan.

End of Project ReportThe Bellsgrove catchment is located in the south-east of County Cavan, on the north-west border of Lough Sheelin and is approximately 9.2 km2 in size. The Bellsgrove stream feeds into Lough Sheelin. Phosphorus loss from agricultural soils to water is perceived as an important water quality issue in the region.E u ropean Union Structural Funding (EAGGF

The phosphorus requirements for silage production on high fertility soils

peer-reviewedThe minimum phosphorus requirement for a mid-season ryegrass was investigated under cutting conditions over a 10-year period at each of three Teagasc sites (Clonroche, Johnstown Castle and Oak Park) in southeast Ireland. Treatments consisted of 0, 20, 30, 40, and 50 kg ha–1 year–1 P applied in autumn. Generally, there were three grass cuts each year and soil samples were taken after the third cut prior to the application of P. Nitrogen and potassium fertiliser was applied to ensure maximum grass yield. There was an emerging treatment effect over time as evidenced by the significance of the treatment × year interaction. The effect of site varied with year reflecting the variability in weather and number of cuts taken at the individual sites. A treatment effect on annual first-cut-silage yield was observed. The largest treatment difference for dry matter (DM) yield of first-cut silage was between the control and the P treated plots (0.32 t/ha). The results show that the draw down of soil-P reserves was adequate to maintain yield for a number of years without additional fertiliser P application. Initial soil tests indicated moderate to high soil test P levels (STP) as measured by the Morgan’s test. Application of P at equivalent to removal rates did not maintain STP. The results suggest that application of a regular small maintenance dressing of P, replacing realistic removals, is the most appropriate fertiliser application strategy.McDonagh/Albatros Fertiliser

Minimum phosphorus needs for silage production.

End of Project ReportPhosphorus recovery in product at the low stocking rates was poor, but improved in the high stocking rates. It is deduced that when the new Teagasc recommendations are implemented, recovery of applied P in product should be very efficient. • Soil should be maintained at Index 2 (3.1 to 6.0 mg P l - 1 ) for optimum silage production • Slurry should be recycled to the silage land early in the year or after 1 st or 2 nd cut silage. • Maintenance fertilizer P should be used to supplement P in the slurry in order to replace removal in milk, meat and other losses • Where slurry is recycled, maintenance fertilizer P for silage land will be less than for grazing land as concentrates are an important source of P input to the farm. The fertilizer P maintenance requirement will normally be between 0 and 10kg P ha -1 yr -1 . • Where slurry is not recycled, maintenance P requirements for silage land are higher at 20 to 30 kg P ha -1 yr -1 • Do not apply insurance P dressings to silage land. It will not increase production and may lead to increased potential for P loss to water.European Union Structural Funding (EAGGF

Phosphorus loss from soil to water.

End of Project ReportThe work described under this project covers field work on phosphorus(P) loss from soil to water under field conditions. In addition two International Workshops on P loss to water, held in Ireland in 1995 and 1998, are also covered under this project. The results indicate that P loss to water is a complex process and it is influenced by a number of factors, including hydrology of the soil, rates and timing of P application and soil P levels. Most work on this subject indicates that there is a positive relationship between soil test P levels and P loss to water. There is need for further work to establish the relative contribution of the different variables involved in P loss from soil to water for different soils and farming conditions. This should help provide answers to the most sustainable methods to minimise losses of P to water and ensure that agricultural production is compatible with good water quality.European Union Structural Funds (EAGGF

The impact of the grazing animal on phosphorus, nitrogen, potassium and suspended solids loss from grazed pastures, Part A

Teagasc wishes to acknowledge the support of the Environmental Research Technological Development and Innovation (ERTDI) Programme under the Productive Sector Operational Programme which was financed by the Irish Government under the National Development Plan 2000-2006.End of project reportIn Ireland 90% of the 4.2 million ha of farmland is grassland. Phosphorus deficiency limited grassland production in Ireland and this was corrected by chemical fertiliser use in the 1960s and 1970s. The increased inputs of fertilisers led to increased intensification of grassland with a doubling of grass yield and of grazing animal numbers, from about 3 million to over 6 million livestock units. There is little information on relative contribution of increased chemical fertiliser use compared to increased grazing animal numbers on phosphorus loss to water. The main objective of this study was to obtain information on nutrient loss, particularly phosphorus, in overland flow from cut and grazed grassland plots, with a range of soil test phosphorus levels over three years and implications.Environmental Protection Agenc

Quantification of phosphorus loss from soil to water.

End of Project ReportThe methods, results and discussion of the project are in five separate sections, 4.1) Phosphorus (P) export from agricultural grassland with overland flow and drainage water (Johnstown Castle); 4.2) Phosphorus export from farm in Dripsey catchment, Co. Cork (NMP); 4.3) Hydrometeorological aspects of farm in Dripsey Catchment (NMP); 4.4) Phosphorus desorption from Irish soils; 4.5) National phosphorus model. Most of the field and laboratory studies were carried out at Johnstown Castle, at UCC and the field site in the Dripsey catchment. The main aim of the project was to quantify the loss of P from soil to water where point source contributions from farmyards were not high. This involved the construction of hydrologically isolated field sites where the quantity of overland flow and the P concentrations for different runoff events from the fields could be measured. In addition, 90 soil samples representative of Irish soils were collected and analysed for the different factors influencing soil adsorption and desorption of P. These results, in addition to catchment data, were used as a first attempt at developing a model that could be used to help predict P loss from soil to water at a catchment scale. The study in the Dripsey was on a farm where water flow and P levels at two points in a stream were measured. The hydrometeorology at this site was also studied. At Johnstown Castle, three overland flow sites, of the order of one hectare each, and one subsurface flow site were studied for P loss to water.Environmental Protection Agency

Pathways for nutrient loss to water with emphasis on phosphorus

Teagasc wishes to acknowledge the support of the Environmental Research Technological Development and Innovation (ERTDI) Programme under the Productive Sector Operational Programme which was financed by the Irish Government under the National Development Plan 2000-2006.End of project reportThe main objective of this project was to study phosphorus (P) loss from agricultural land under a range of conditions in Ireland, to quantify the main factors influencing losses and make recommendations on ways to reduce these losses. This report is a synthesis of the main conclusions and recommendations from the results of the studies. The final reports from the individual sub-projects in this project are available from the EPA (www.epa.ie).Environmental Protection Agenc

A critical edition of Home's Douglas

Thesis (M.A.)--University of Kansas, English, 1924

Spatial variation of soil test phosphorus in a long-term grazed experimental grassland fieldweijun fu1, 2

The spatial variation of soil test P (STP) in grassland soils is becoming important because of the use of STP as a basis for policies such as the recently EU-introduced Nitrate Directive. This research investigates the spatial variation of soil P in grazed grassland plots with a long-term (38 y) experiment. A total of 326 soil samples (including 14 samples from an adjacent grass-wood buffer zone) were collected based on a 10 x 10 m(2) grid system. The samples were measured for STP and other nutrients. The results were analyzed using conventional statistics, geostatistics, and a geographic information system (GIS). Soil test P concentrations followed a lognormal distribution, with a median of 5.30 mg L(-1) and a geometric mean of 5.35 mg L(-1). Statistically significant (p < 0.01) positive correlation between STP and pH was found. Spatial clusters and spatial outliers were detected using the local Moran's I index (a local indicator of spatial association) and were mapped using GIS. An obvious low-value spatial-cluster area was observed on the plots that received zero-P fertilizer application from 1968 to 1998 and a large high-value spatial-cluster area was found on the relatively high-P fertilizer application plots (15 kg ha(-1) y(-1)). The local Moran's I index was also effective in detecting spatial outliers, especially at locations close to spatial-cluster areas. To obtain a reliable and stable spatial structure, semivariogram of soil-P data was produced after elimination of spatial outliers. A spherical model with a nugget effect was chosen to fit the experimental semivariogram. The spatial-distribution map of soil P was produced using the kriging interpolation method. The interpolated distribution map was dominated by medium STP values, ranging from 3 mg to 8 mg L(-1). An evidently low-P-value area was present in the upper side of the study area, as zero or short-term P fertilizer was applied on the plots. Meanwhile, high-P-value area was located mainly on the plots receiving 15 kg P ha(-1) y(-1) (for 38 y) as these plots accumulated excess P after a long-term P-fertilizer spreading. The high- or low-value patterns were in line with the spatial clusters. Geostatistics, combined with GIS and the local spatial autocorrelation index, provides a useful tool for analyzing the spatial variation in soil nutrients