Pathways for Nutrient Loss to Water; Slurry and Fertilizer Spreading

End of project reportThere are almost 150,000 farms in Ireland and these contribute substantial quantities of N and P to inland and coastal waters. Some of these nutrients are carried from wet soils by overland flow and by leaching from dry soils. Farm practice can reduce the loss from farms by judicious management of nutrients. Improvements are required to diminish export of nutrients without impairing operations on the farm. Literature regarding nutrient loss from agriculture was reviewed in this project and maps were prepared to predict best slurry spreading times around Ireland. Two further maps were prepared to show slurry storage requirement on farms

Nitrous Oxide Emissions

End of project reportNitrous oxide (N2O) is one of the three most important greenhouse gases (GHG). Nitrous oxide emissions currently account for approximately one third of GHG emissions from agriculture in Ireland. Emissions of N2O arise naturally from soil sources and from the application of nitrogen (N) in the form of N fertilizers and N in dung and urine deposition by grazing animals at pasture. Nitrous oxide emission measurements were conducted at three different scales. Firstly, a large-scale field experiment was undertaken to compare emission rates from a pasture receiving three different rates of N fertilizer application and to identify the effects of controlling variables over a two-year period. Variation in emission rates was large both within and between years. Two contrasting climatic years were identified. The cooler and wetter conditions in year 1 gave rise to considerably lower emission levels than the warmer and drier year 2. However, in both years, peak emissions were associated with fertilizer N applications coincident with rainfall events in the summer months. A small-plot study was conducted to identify the individual and combined effects of fertilizer, dung and urine applications to grassland. Treatment effects were however, difficult to obtain due to the overriding effects of environmental variables. Thirdly, through the use of a small-scale mini-lysimeter study, the diurnal nature of N2O emission rates was identified for two distinct periods during the year. The occurrence of a diurnal pattern has important implications for the identification of a measurement period during the day which is representative of the true daily flux. The research presented aims to identify the nature and magnitude of N2O emissions and the factors which affect emission rates from a grassland in Ireland. Further work is required to integrate the effects of different soil types and contrasting climatic regimes across soil types on N2O emissions.Environmental Protection Agenc

Monitoring of nitrogen leaching on a dairy farm during four drainage seasons

peer-reviewedThe authors acknowledge funding from the Environmental Protection Agency and Teagasc under the 2000–2006 RTDI programme.The effect of four commonly used dairy farm management systems (treatments), on nitrogen leaching to 1 m was studied over a 4-year period from October 2001 to April 2005. The treatments were (i) grazed plots receiving dirty water, (ii) 2-cut silage plots receiving slurry, (iii) grazed plots and (iv) 1-cut silage plots receiving slurry. All plots had fertiliser N applied; the soil was free-draining overlying fissured limestone. Mean 4-year N input (kg/ha) was 319 and mean annual stocking density was ~2.38 LU/ha. The annual average and weekly NO3-N and NH4-N concentrations in drainage water were analysed for all years, using a repeated measures analysis. For the annual NO3-N data, there was an interaction between treatment and year (P < 0.001). There were significant differences (P < 0.05) in NO3-N concentrations between the treatments in all years except the third. For the NH4-N data there was no interaction between treatment and year or main effect of treatment but there were differences between years (P < 0.01). Mean weekly concentrations were analysed separately for each year. For NO3-N, in all years but the third, there was an interaction between treatment and week (P < 0.001); this occurred with NH4-N, in all 4 years. Dirty water was significantly higher than grazed-fertiliser only and 1-cut silage in NO3-N concentrations in 2001–02; in 2002–03, dirty water and 2-cut silage were significantly higher than the other treatments; while in 2004–05, dirty water and grazed-fertiliser only were significantly higher than the other two treatments. The overall 4-year mean NO3-N and NH4-N concentrations were 8.2 and 0.297 mg/L, respectively.Environmental Protection Agenc

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

Land Spreading of Animal Manures, Farm Wastes & Non-Agricultural Organic Wastes. Part 1 manure (and other organic wastes) management guidelines for intensive agricultural enterprises.

End of Project ReportThe objective of the Teagasc Manure (and Other Organic Wastes) Management Guidelines for IAE are to provide an operational framework for the agronomically efficient and environmentally safe recycling of these organic by-products, maximising the benefits of nutrients they contain at minimum cost. The principles of the approach are equally applicable to the management of all manures and organic wastes applied to land. The approach includes programmes for controlling manure quantity and quality; operational procedures covering storage, transport and nutrient management; and a quality assurance programme. These Guidelines assign the importance of manure management on an equal footing with other production practices. Implementation of these Guidelines may entail higher costs c o m p a red with traditional practices. However, some of the benefits accruing from the improved management practices can partly or wholly offset the costs of implementation.European Unio

Effect of Agricultural Practices on Nitrate Leaching

Teagasc wishes to acknowledge with gratitude funding from the 2000-2006 EPA RTDI programme in financing this research project.End of project reportA farm-scale study, carried out at Teagasc, Moorepark (Curtin’s farm), examined the effect of four managements (treatments) on nitrate-nitrogen (NO3-N) leaching over the period 2001-`05. Leaching was measured in these treatments: (T1) plots receiving dirty water and N fertilizer which were grazed; (T2) 2-cut silage and grazing plots receiving slurry and fertilizer N; (T3) grazed plots receiving fertilizer N and (T4) 1-cut silage and grazing plots receiving slurry and fertilizer N. The soil is a free-draining sandy loam overlying Karstic fissured limestone. The mean direct N inputs (kg/ha) for T1-T4 in 2001-`04 were 311, 309, 326, 331, respectively, with stocking rates (LU/ha) of 2.12 - ~2.47. Eight ceramic cups per plot, in 3 replicate plots of each treatment, were used to collect water, on a weekly basis, from 1.0 m deep using 50 kPa suction. There were 33, 37, 26 and 24 sampling dates in the 4 years, respectively. The NO3-N and NH4-N concentrations (mg/l) were determined in the water samples. The annual average and weekly concentration of these parameters was statistically analysed for all years, using a repeated measures analysis. The aggregated data were not normally distributed. There was an interaction between treatment and year (p<0.001). Significant differences (p=0.05) in NO3-N concentrations showed between the treatments in years 1, 2, 4 but not in year 3. For the NH4-N data there was no interaction between treatment and year, p=0.12, or main effect of treatment, p=0.54 but there were differences between years, p=0.01. Mean weekly concentrations were analysed separately for each year. For NO3-N, in years 1, 2 and 4 there was an interaction between treatment and week (p<0.001). With NH4-N, there was an interaction between treatment and week in all 4 years. Dirty water was significantly higher than grazed and 1 cut silage in NO3-N concentrations in year 1; in year 2, dirty water and 2 cut silage were significantly higher than the other treatments while in year 4, dirty water and grazed were significantly higher than the other two treatments. The overall four-year weighted mean NO3-N and NH4-N concentrations were 8.2 and 0.297 mg/l. The NCYCLE (UK) model was adapted for Irish conditions as NCYCLE_IRL. The NCYCLE empirical approach proved to be suitable to predict N fluxes from Irish grassland systems in most situations. Experimental data appeared to agree quite well, in most cases, with the outputs from NCYCLE_IRL. The model was not capable of predicting data from some of the leaching experiments, which suggests that the observed leaching phenomena in these experiments could be governed by non-average conditions or other parameters not accounted for in NCYCLE_IRL. An approach that took into account denitrification, leaching and herbage yield would probably explain the differences found. NCYCLE_IRL proved to be a useful tool to analyse N leaching from grazed and cut grassland systems in Ireland.Environmental Protection Agenc

An Algebraic Approach to Mso-Definability on Countable Linear Orderings

We develop an algebraic notion of recognizability for languages of words indexed by countable linear orderings. We prove that this notion is effectively equivalent to definability in monadic second-order (MSO) logic. We also provide three logical applications. First, we establish the first known collapse result for the quantifier alternation of MSO logic over countable linear orderings. Second, we solve an open problem posed by Gurevich and Rabinovich, concerning the MSO-definability of sets of rational numbers using the reals in the background. Third, we establish the MSO-definability of the set of yields induced by an MSO-definable set of trees, confirming a conjecture posed by Bruyère, Carton, and Sénizergues

Environmental Monitoring on Research Centres and Large Farms Using Spatial Data Management Tools.

End of Project ReportThe objective of project 4480 was to build an environmental management system by using a visual or map based approach to develop new ways to manage environmental data on a large farm or an estate of several farms. Geographic information system (GIS) techniques are extremely powerful, but they tend to be complex, and often require a high degree of skill and training in order to use them. Using systems analysis, the fundamental environmental management data were identified and a simplified spatial approach was developed to manage these environmental data. Johnstown Castle Research Centre consists of three farms, ornamental grounds, forests, lakes and streams. A set of database tables was generated to hold farm environmental data on these farms. These included: annual management summary data giving the average number of different types of animals, the amount of organic manure and N, P and K nutrients produced by them, fertiliser purchases, organic and chemical nutrient usage on the farm, achievement of nutrient management planning targets, etc. monthly livestock information recording the numbers of livestock of different types for the three farms, together with management comments on the changes and transfer that take place over the month, detailed land use and nutrient use information for each field or plot on the estate, recent soil analyses information for the experimental plots, analysis results of recent water samples which are taken regularly at sampling points throughout the estate. The topographical, soil and site features were digitised, in order to collect information on the overall and individual farm boundaries. This included roads, hedges and ditches, streams, rivers and lakes, the buildings and most particularly, the boundaries of all field and experimental plots. When the digitisation was complete, a set of bespoke programs was built, using the GIS system, ArcView. To make the system "user friendly", the menu system was customised by removing complex features; retaining only those buttons and menu options that served a purpose useful to the application. The programs were unified into a PC system called Johnstown Castle Environmental Monitoring System or JCEMS. For the future, it is envisaged that the maps and spatial techniques will be embodied into an Access database system and developed for use by other research stations and farms.European Union Structural Funding (EAGGF

Optimal use of animal slurries for input reduction and protection of the environment in sustainable agricultural systems.

End of Project ReportThis work was funded by the EU Air Programme (AIR-CT 94-1276) 1st October 1994 - 30th September 1997The objectives of manure management in sustainable agricultural systems are to optimise nutrient recovery by the crop and to reduce nutrient losses to the environment. However, farmers still have many practical problems in adopting and applying the research developed for improving manure management strategies. This project identified and addressed three of these problems. These concerned the provision of decision support in relation to environmental risk assessment and application decision strategies; determining the nutrient value of slurry and the development of manure application technology.European Structural Funding (EAGGF