Noel Culleton

The fate of phosphatic fertiliser applied to grassland

Abstract Phosphorus is an essential element for healthy plant and animal growth. The soils of Ireland were very poor in phosphorus status in the 1950s. Repeated applications of phosphorus over the decades has resulted in the soil phosphorus levels rising from 1 to 9 mg/1 of soil. This paper assesses the fate of applied phosphatic fertiliser over a 30 year period on a grassland site that was rotation‐ally grazed by beef animals for each grass growing season. The treatments were 0, 15 and 30 kg P/ha applied annually in spring. The amount of P that was exported in beef ranged from 6 percent to 20 percent suggesting that most of the P was still in the soil or lost via overland flow. The total loss of P fertiliser via overland flow over 30 years from plots with a Morgans soil test of 6 and 17 mg/1 were 19 and 130 kg/ha, respectively. Mass balance studies showed over 75 percent of the applied P remained in the soil. A large portion of this phosphorus was accumulated near the soil surface.

The application of parameters designed to measure nature conservation and landscape development on Irish farms.

Abstract Research has not been previously carried out in Ireland on methods of measuring nature conversation and landscape development on Irish farms. Parameters for measuring the development and improvement of farm landscapes in the EU were applied on two organic farms and two conventional farms to test their suitability for measuring nature and landscape development under Irish conditions. In all 86 parameters were evaluated. All the parameters were applied successfully. Some were more useful than others in this investigation but all were retained so that all the situations which influence nature and landscape in Ireland could be covered. Application of the parameters showed that organic farming has an overall positive effect on landscape and nature production on farms and has no negative effects. Conventional farming can have some positive environmental effects but has neutral or negative effects in most cases. The results show that the methodology used in this paper provide a suitable prototype for measuring landscape development on Irish farms.

Sustainability in Irish Agriculture

Recent decades have seen increasing intensification in Irish agriculture, resulting in some degradation of natural resources. Concerns resulting from this have led to a current emphasis on sustainable agriculture which is a food production and distribution system that meets the needs of the present generation without compromising the ability of future generations to do likewise. In a soil fertility context, sustainable agriculture entails the maintenance of the balance between nutrients being removed by crops or animal produce and nutrient inputs from fertilisers and nutrient recycling. Phosphorus and nitrogen are key elements in agricultural productivity, but if used to excess can lead to pollution of rivers and lakes, and require greater monitoring, as well as close attention to rates and times of application. An integral part of the reform of the Common Agricultural Policy is the increased emphasis on environmental conservation through measures aimed at integrating environmental and agricultural policy...

Meso-scale systems used for the examination of different integrated constructed wetland operations

Meso-scale constructed wetlands have not been commonly used for the examination of interactions and operations within differently designed wetland systems. Sixteen meso-scale constructed wetland systems (4 operations with 4 replicates each) were therefore evaluated between November 2008 and June 2010. These systems were used to examine key operations identified in the literature including hydraulic loading rates, nutrient loading rates and nutrient recycling modes. The wetlands were managed in the following modes: normal, recycling, high nutrient loading and high flow rate. The designs were such that the influents could be varied at set loading rates and concentrations. The ammonia removal rates for the meso-scale integrated constructed wetland (ICW) systems were similar to other full-scale ICW systems that have been in operation in the south-east of Ireland for the past decade. These comparable results highlight the potential cost-effectiveness of these meso-scale experimental designs for the examination of novel operations for future ICW developments.

The use of integrated constructed wetlands for the treatment of swine wastewaters

Introduction The treatment of agricultural wastewaters (yard runoff, dairy washings, slurries) by means of land-spreading is under scrutiny due to the EU Nitrates Directive, which limits the amount of nitrogen that can be applied to land. These limits have particular challenges for Piggery management, because they have limited access to spread-lands compared to other farming enterprises. This makes the nutrient content of pig slurries a potentially costly issue to address. The use of alternative methods to supplement or even replace land-spreading have been investigated for several decades with Constructed Wetlands showing potential for the treatment of agricultural wastewaters, including that of swine wastewater (slurry). The objective here was to examine the treatment efficiency of an Integrated Constructed Wetland (ICW) approach for the treatment of anaerobically digested swine wastewater. ICW systems are surface-flow constructed wetlands that treat wastewaters through means of natural processes, sedimentation, mineralization, plant and microbial uptake, denitrification, nitrification and atmospheric releases.

Comparative Effects of Organic Manures on Spring Herbage Production of a Grass/White Clover (c.v. Grasslands Huia) Sward

A relatively low level of herbage production in the spring is a major disadvantage of grass/white clover [ Trifolium repens (L.)] swards. The objective of this experiment was to investigate the effect of cattle slurry and farmyard manure (FYM) on spring herbage production from grass/white clover (c. v. Grasslands Huia) swards in temperate grassland. Four treatments were used. Cattle slurry [3000 L ha” 1 ; approximately 6% dry matter (DM)] was applied to plots in mid-August 1993 and 1994 (summer application), or mid-March 1994 and 1995 (spring application). Twenty t ha −1 of FYM (approximately 20% DM) was applied in mid-March 1994 and 1995. No manure was applied for the control. Treatments were arranged in a randomised complete block design and replicated six times. Herbage DM yields were assessed in May 1994 and 1995. In May 1994 treatments yielded an average of 3.42 t DM ha −1 and there was no significant ( P 0.05) difference between treatments. In May 1995 there was no significant ( P 0.05) difference in herbage DM yields between the FYM (1.77 t ha −1 ) and the spring-applied slurry (1.71 t ha −1 ) treatments. Both of these treatments had significantly ( P 0.05) higher yields than the summer-applied slurry (1.02 t ha −1 ) and the control (0.98 t ha −1 ) which were not significantly ( P 0.05) different from each other. Response to the cattle slurry and FYM applied in March was primarily in terms of increased grass production which accounted for ca 90% of spring herbage yields. The three manure treatments resulted in a decrease in the extent of white clover stolon development and in the white clover content of herbage compared to the control. However, the spring-applied slurry favoured stolon survival during winter, and the clover content of herbage in the spring; hence it favoured the persistency of the clover in the sward relative to the other manure treatments. The three manure treatments maintained soil phosphorus, potassium, and magnesium concentrations in line with the requirements of optimum production from grass/white clover swards.