• Nutrient management planning on Irish dairy farms

      Mounsey, J.; Sheehy, J.; Carton, Owen T.; O'Toole, P. (Teagasc, 1998-09-01)
      The objective of the work undertaken was to investigate nutrient use on intensive dairy farms. A survey of 12 dairy farms was undertaken in 1997 to determine nutrient management practices. These were compared with current nutrient advice and recommended practices. Data recording was completed by the farmer and supplemented by regular farm visits to assist with and validate the process. The mean farm size was 64.8 ha with an average of 128 cows and an annual milk yield per cow of 5594 kg. The mean stocking rate was 2.58 Livestock Units/ha. Dairy cows accounted for highest proportion of the total livestock with most of the younger stock consisting of dairy replacements. Approximately 80% of soil P levels were greater than 6 mg/l while 67% of soils had soil K levels in excess of 100 mg/l. The mean soil P and K levels on the grazing and silage areas were 11 and 128 mg/l, 12 and 117 mg/l, respectively. The mean farm nutrient balance (inputs - outputs) established an annual surplus of N, P and K of 304, 18 and 53 kg/ha, respectively. The adoption of nutrient management plans instead of current practice would reduce N, P and K inputs on average by 44, 13 and 24 kg/ha, respectively. The use of the Teagasc revised P nutrient advice would further reduce the P input requirements by 2 kg/ha. On average the farms had 90% of the 16 week slurry storage capacity. Approximately 14, 42, 14 and 31% of the slurry was applied in spring, summer, autumn and winter, respectively. In all cases there was significant between farm variability. The soil P fertility on the survey farms is skewed towards index 3 and 4 when compared with the average for all samples received at Johnstown Castle. There is no agronomic advantage in terms of crop or animal production for soils to have P levels in excess 10 mg/l. This result indicates that P inputs to farms of this type can be reduced in many cases without prejudicing production potential. The nutrient balance conducted highlighted the extent of the nutrient surpluses and the between farm variability. The data suggest that there is not a serious nutrient surplus on the survey farms, which would require the use of additional off-farm land for slurry recycling, as obtains on pig and poultry farms. The study also indicates that although farm unit cost savings may be small in adopting nutrient management planning, overall farm savings may be significant. For example on the survey farms, savings of up to £2,000 can be achieved apart from the obvious positive environmental impact.
    • Development and Evaluation of Caseins/Caseinates for use as Ingredients in Food Products

      Mehra, Raj; Walsh, Daniel; O'Kennedy, Brendan; Kelly, Phil (Teagasc, 1998-09-01)
      The overall objective of this project was to investigate the effects of key processing steps in the industrial production of acid casein on the characteristics and functionality of sodium caseinate with particular emphasis on analytical/functionality testing and seasonal/lactational effects on the original milk. The main conclusions were as follows: The most significant result indicates that drying and concentration after washing of the acid casein curd are responsible for alterations in the structure of casein, which result in sodium caseinates with different properties. This was confirmed in the case of two acid casein plants investigated which showed similar results even though using different washing and drying technologies. This difference due to the drying step may be further amplified depending upon whether commercial sodium caseinate is manufactured from acid casein in the dried or wet curd state. The analytical and functional testing methodology adapted in our laboratory proved effective in predicting the effects of processing steps on the functionality of sodium caseinate. In particular, the ability to detect the presence of aggregate formation was particularly important. The database generated subsequently helped an acid casein manufacturer in modifying its process(es) to manufacture experimental sodium caseinate for specific food end-uses. Progress was greatly facilitated by the collaboration of individual manufacturers in the sourcing of problem samples from previously manufactured codes, and facilitating access to process plant during production. In a commercial application of the database, confidential work was undertaken on behalf of a client. Experimentally-produced sodium caseinate ingredients were evaluated using our adapted functionality testing methods and based on the results, the company was able to modify its process(es) to produce sodium caseinates with functionality for specific food end-users. It was concluded that while processing parameters in the production of acid casein can have a significant effect on the functional behaviour of the resultant sodium caseinate, the ability to assess this change in functional behaviour, through relevant functional testing, was equally important.
    • Factors affecting the composition and use of camelina

      Crowley, J.G.; Fröhlich, A. (Teagasc, 1998-09-01)
      Camelina (Camelina sativa), a member of the mustard family, is a summer annual oilseed plant. Winter hardy types also exist. False flax and Gold of Pleasure are the popular common names for the crop. The crop was widely grown in Eastern Europe and Russia up to the early 1940’s but was replaced with the introduction and widespread use of oilseed rape. The revival of interest in camelina oil is due to its high linolenic acid (38%) content. Linolenic acid is one of the OMEGA-3 fatty acids which are generally found in substantial quantities only in linseed and fish oils. Camelina offers an opportunity to supply the growing demand for high quality edible oils rich in OMEGA-3 fatty acids. A three year study established that camelina is a very suitable crop to grow in Ireland, producing 2.5 t/ha of high quality seed (42-47%) with no agrochemical inputs required. The oil contains 35 to 40% linolenic acid compared to 8% in rape and soya oils. The oil does not deteriorate during refining or storage and can be used in a number of oil based products such as spreads and salad dressings.
    • Biodiesel production from camelina oil, waste cooking and tallow.

      waste cooking oil; Rice, Bernard; Frohlich, A.; Leonard, A. (Teagasc, 1998-09-01)
      The high cost and lack of availability of raw materials is limiting the expansion of bio-diesel production. The aim of this project was to examine the potential of alternative vegetable oils, oil wastes or animal fats as bio-diesel feedstocks, and the performance of road vehicles using bio-diesel blends made from these materials. Three feedstock materials were considered: waste cooking oil from the catering industry, Camelina oil, and beef tallow. Thirty-four 300-litre pilot-scale batches of these materials were esterified, and yields and bio-diesel properties were measured. Five growers produced about 6 ha of camelina sativa on their set-aside land. Vehicle performance trials were carried out with five fuel blends involving bio-diesel and mineral fuel. A plant to produce approx 3000 tonnes per annum of bio-diesel was specified and costed. The work has concluded that waste cooking oil is the most promising raw material for the immediate start-up of bio-diesel production. A proportion of camelina oil could also be used. Further work is required to overcome technical problems with tallow. The cost of bio-diesel production in a 3000 t/yr plant from these raw materials was estimated at from 27 to 32 pence per litre of fuel. Reduction of excise on biodiesel to the level applied to heating and agricultural fuels would make its final price competitive with mineral diesel for road use. The excise remission could be justified by a reduction of global warming and harmful vehicle exhaust emissions, and the provision of a safe disposal system for otherwise waste materials.
    • Influence of Enterococci and Thermophilic Starter Bacteria on Cheddar Cheese Flavour

      Beresford, Tom; Cogan, T.; Wallace, J.; Drinan, D.; Tobin, S.; Piveteau, P.; Carroll, N.; Deasy, B. (Teagasc, 1998-09-01)
      This project set out to identify suitable enterococci and thermophilic starter strains which could be added to the cheese during manufacture (as starter adjuncts) with the specific aims of enhancing flavour during ripening as well as facilitating flavour diversity - a trait sought by many commercial Cheddar companies. This project confirmed the potential of thermophilic lactic acid strains to affect flavour when used as starter adjuncts in Cheddar cheese manufacture. Their use can also lead to the development of novel flavours. Many adjunct cultures proposed to-date to enhance Cheddar flavour are composed of strains of lactococcal starter, selected for their flavouring capacity. However, application of such strains in industry would lead to increased probability of phage attack on the primary starter. On the other hand, thermophilic lactic acid strains are phage unrelated to conventional starter and thus would not lead to the introduction of starter specific phage into the cheese plant. A thermophilic strain from the Moorepark collection (DPC 4571) was shown to have major commercial potential as a flavour enhancer.
    • Epidemiology and control of pink rot in potatoes.

      O'Sullivan, E.; Dowley, L.J. (Teagasc, 1998-09-01)
      Rotting of tubers was reported in early potato crops in Co. Wexford in 1995. Geotrichum candidum, which causes a condition known as rubbery rot, was isolated from a sample of affected tubers. In further investigations in 1996 both G. candidum and Phytophthora erythroseptica, the cause of pink rot, were isolated from diseased tubers. In pathogenicity tests P. erythroseptica re-infected tubers while G. candidum did not. It was concluded that the disease was pink rot. In 1997 foliar applications of the systemic fungicide metalaxyl were evaluated for its control. The level of control obtained was insufficient to overcome the problem which pink rot can cause in early potatoes.
    • Use of Bacteriocins to Improve Cheese Quality and Safety

      Ross, R. Paul; Hill, Colin; Ryan, Maire; Cunniffe, Alan; McAuliffe, Olivia; Murray, Deirdre; O'Keefe, Triona; Rea, Mary (Teagasc, 1998-09-01)
      The objectives of this project were to generate, characterise and exploit a range of novel bacteriocin producing starter cultures to improve both the safety and the quality of fermented dairy foods. The main conclusions were as follows: Lacticin 3147 is a broad spectrum bacteriocin which inhibits a wide range of Gram-positive bacteria including lactobacilli, clostridia and Listeria. The bacteriocin has been purified by chromatographic procedures and has been shown to be composed of two peptides, both of which are required for biological activity. The mechanism of action of lacticin 3147 has been elucidated. The entire plasmid encoding lacticin 3147 has been sequenced and the bacteriocin in distinct from any previously characterised lactococcal bacteriocin. The Food Grade introduction of the bacteriocin genes into cheese starters was carried out. Lacticin 3147 producing starters have been used to control the pathogen Listeria monocytogenes on the surface of mould ripened cheese. Lacticin 3147 producing starters have been used to control the non-starter lactic acid bacteria complement in Cheddar cheese during the ripening process. A novel starter system using a bacteriocin (lactococcin)- producing adjunct has been designed which gives increased cell lysis during Cheddar cheese manufacture while ensuring that efficient acid production is not compromised. In summary these studies have found that naturally occurring antimicrobials such as bacteriocins have a wide range of applications in the food industry for improving both the quality and safety of fermented dairy products.
    • Horticultural Growing Media and Plant Nutrition (a)

      Maher, M.J. (Teagasc, 1998-09-01)
      This publication reports on four different studies under the overall title: (1)The effect of type and rate of controlled release fertiliser on the performance of hardy nursery stock in containers; (2) Analysis of substrates containing controlled release fertilisers; (3)The effect of water quality and rate of lime on the growth of nursery stock plants in peat; (4)Effect of suSCon Green on the growth of nursery stock plants
    • Dairy Ingredients in Chocolate

      Keogh, M.K.; O'Kennedy, Brendan; Twomey, M.; O'Brien, N.; Kennedy, B.; Gorry, C. (Teagasc, 1998-09-01)
      The main objective was to assess and control the contribution of various ingredient components to chocolate behaviour and to optimise ingredients for specific chocolate applications. A key aim, therefore, was to understand the role of composition and particle structure and to produce spray dried powders with a functionality in chocolate as close as possible to roller dried powders. By demonstrating how the powder properties affect chocolate, it should be possible to control the functional properties of the powders to meet any powder or chocolate specification. Novel powder compositions indicated by this work should also be useful to chocolate makers. The ability to make chocolate under test conditions and to assess the role of milk powders or other ingredients has been put in place for the first time in Ireland. Previous knowledge of milk seasonality and of powder technology has provided a basis for understanding variations in milk powder functionality in chocolate. Spray dried powders with mean free fat values of 50 to 94%, particle sizes of 30 to 65 mm and vacuole volumes of 0.0 to 3.9 ml/100g were produced from milks of varying composition but under the same processing conditions. Advances were made in analysing powder structure through microscopy, particle size and occluded air measurement. Valuable new information has been generated on the changes in free fat, solid fat content, particle size and occluded air in powders. Explanations were provided for the first time for the complex effects of these properties on chocolate viscosity and yield value. This information will also make a positive contribution to other projects in the milk powder area. Good contacts have been established with multinational manufacturers and with producers of milk powder for chocolate.
    • Assessment of Food Ingredient Functionality using Laser Microscopy

      Keogh, M.K.; Auty, Mark (Teagasc, 1998-09-01)
      The objectives of this project were, to establish a confocal microscopy facility at Moorepark, to develop suitable methodology for the examination of food products and ingredients, to apply confocal microscopy techniques to food research projects and to use the above technological expertise for commercial applications in the Irish Food Industry. The confocal laser scanning microscopy (CLSM) facility is now established and is fully integrated into the Teagasc research program at Moorepark. The new Confocal Microscopy Service has attracted significant commercial interest and client work is expanding. Results show that confocal laser scanning microscopy is a valuable technique for assessing the functionality of food ingredients in a wide range of food products, as well as being a powerful problem-solving tool. Work is ongoing to develop further specific ingredient localisation techniques, and to promote commercial awareness of the service. Confocal laser scanning microscopy offers a unique contribution to product research and development in the Irish food industry.
    • Infiltration rate assessment of some major soils.

      Diamond, J.; Shanley, T. (Teagasc, 1998-09-01)
      Landspreading of fertilisers and wastes require an evaluation of the risk of overland flow in order to minimise risks of polluting rivers and lakes. Infiltration capacity measurements offer a practical means of indexing runoff risk. The objectives of this study were to assess the spatial and temporal variability of infiltration capacity and to assess the capacity of some major Irish soils. Infiltration capacity was measured using double ring infiltrometers at freely drained (8) imperfectly drained (1) and poorly drained (1) sites. The first series was performed for one day in summer. Eight years later a second series was conducted for two days in winter and summer at the same sites. On average six replicates were required in summer and fourteen in winter to estimate the mean with 50 percent precision. Capacities were reasonably stable between years but there was a significant difference between seasons. Capacities in summer were about 3.5 times the winter values. Except on the poorly drained soil the infiltration capacity exceeded or equalled the five year return rainfall rate indicating a very small risk of overland flow in summer. In winter the capacity at three sites, including freely drained sites, were less than 2.5 mm hr-1 indicating a significant general risk in winter.
    • Ammonium thiosulphate as an environmentally friendly tool for reducing N inputs.

      Murphy, Matthew D. (Teagasc, 1998-09-01)
      The overall objective of the EU funded project was to evaluate the ability of ammonium thiosulphate (ATS) to act as an inhibitor of urease and nitrification processes and as a source of plant nutrient S when added to solid and liquid fertilisers and to slurries. These initial experiments have shown the need for further research on (a) applying ATS directly to the soil rather than to the herbage surface, and (b) adding ATS to the slurry in the storage tank simultaneously with slurry excretion.
    • Horticultural Growing Media and Plant Nutrition (b)

      Maher, M.J. (Teagasc, 1998-09-01)
      The Effect of Planting Density on the Production Of Potato Minitubers Under Protection: Micropropagation of potatoes can be used to bulk up stocks of new cultivars or disease free stocks of existing cultivars. Rooted microplants are grown under protection to produce minitubers which undergo multiplication over a number of generations to produce seed potatoes. The object of these experiments, undertaken for Dubcap Ltd., was to study the effect of planting density on minituber production under greenhouse conditions. They were also designed to serve as a basis for assessing the feasibility for recycling minitubers especially small (8-15 mm) ones which have been shown not to perform satisfactorily under field conditions. The experimental system was designed to serve as a prototype for a commercial operation which would function as a satellite production site remote from the tissue culture laboratory. Development Of A Growing Medium Based On Forest Tree Bark: The aim of these experiments was to develop a plant growing medium based on 100% Sitka spruce bark through first studying the effect of rate of application and source of nitrogen on the composting of milled sitka spruce bark and then optimising the nutrient addition to the composted bark.
    • Repeated low rate herbicide applications for weed control in scallions.

      Murphy, Richard F.; Marren, Peter (Teagasc, 1998-09-01)
      The main objective of this investigation was to determine if satisfactory weed control in vegetable crops (scallions) could be achieved and overall chemical use reduced by very repeated low dose applications of contact and contact residuals herbicides. The trials showed that scallion crops could tolerate certain post-emergence herbicides better than weed populations earlier in their life cycle provided the first true leaf of the crop had reached 1.5- 2cm in length . Various combinations or cocktails of herbicides of cyanazine, oxyfourfen, ioxynil and gesagard were tested both at Kinsealy and in several commercial locations in Co. Dublin at very low rates varying from 17 to 70g/ha and these were compared with current standard post-emergence recommendation of single rate ioxynil at 0.4-0.7 kg/ha. Each of the cocktail combinations apart from ioxynil and cyanazine produced highly satisfactory weed control when repeated at 7-12day intervals commencing when the first true leaf averaged 2cms long, over a wide range of conditions. The most effective and satisfactory weed control was achieved from either the oxyflourfen (17- 35g/ha) plus cyanazine (35-70g/ha) or the ioxynil(17-35g/ha) plus gesagard (17-35g/ha) combinations. These matched the weed control given by the standard recommended treatment of ioxynil with the advantage of a reduction of up to 50% chemical usage.
    • Better management and economy of the N resource in Ireland.

      Ryan, M. (Teagasc, 1998-09-01)
      The project, which was carried out at Johnstown Castle, was concerned with measuring denitrification at depth in grazed grass plots receiving 362 kg fertiliser N per ha. Reports in the scientific literature had indicated that such was likely, given the conditions necessary for the denitrifying microbial reactions to take place. In one experiment, denitrification was detected in measurable amounts to 90cm soil depth in spring-summer, using the acetylene block technique. A second more extensive experiment carried out under similar conditions within one year from March to August and from October to March looked at denitrification in greater detail to 50 cm deep. Results showed the importance of soil water and soil ammonium (NH4) to rate of denitrification. The rate was much greater in the 0-10 cm layer than in the lower layers in both time periods. Of the total denitrification occurring in the 0-50 cm layers in the year, which was 16.6 kg N per ha, 80% occurred at 0-10 cm with 62% occurring in the second time period, October to March.
    • Optimal use of animal slurries for input reduction and protection of the environment in sustainable agricultural systems.

      Carton, Owen T.; Lenehan, J.J.; Ryan, D. (Teagasc, 1998-09-01)
      The 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.
    • Factors affecting the yield of winter lupins.

      Crowley, J.G. (Teagasc, 1998-09-01)
      The white lupin (Lupinus albus) is a temperate legume whose seed contains high levels of protein (36-44%), oil (10-16%) and high quality dietary fibre in the dry matter. Modern varieties contain extremely low levels of alkaloids (<0.01%) and no anti-nutritional factors. Thus their composition is more similar to soya bean than peas and beans, which contain much less protein (23-27%) and no oil. Nitrogen fixation by autumn-sown, determinate varieties is large (ca. 300 kg/ha) and harvest index for nitrogen is high (more than 85% of the crop N is recovered in the grain). Lupins also have the ability to release phosphorus and iron from mineral sources in the soil. These two characteristics make the winter lupin crop an ideal choice as a low input alternative crop, particularly in nitrogen-sensitive areas. Attempts to introduce spring-sown lupins have failed, mainly due to low yield potential, poor yield stability and late harvest. The release of the first winterhardy determinate varieties by French breeders in 1994 promised the first real chance of success. The successful introduction of lupins offers the possibility of reducing soya bean imports and replacing it with a high-quality, home-grown protein source, with the added advantage of traceability. Autumn-sown lupins are capable of producing satisfactory yields (3.7-4.5 t/ha). The crop does require careful management, i.e. early sowing (by mid-September), at the correct seed rate (100 kg/ha), into well-structured free-draining soil and with a pH below 7. Sown in early September, the crop will mature from late August to mid-September.
    • Bi-cropping of winter wheat and white clover.

      Burke, J.I.; Thomas, T.M.; Finnan, John. (Teagasc, 1998-09-01)
      Growing cereals in a leguminous living mulch (bi-cropping) could potentially reduce the need for synthetic inputs to cereal production while preventing losses of nutrients and increasing soil biological activity. The objective of this project was to investigate how bi-cropping (a low input production system for cereals) would compare with conventional winter wheat production systems in terms of total biomass, grain yield and biological diversity. This study has resulted in valuable information on bi-cropping being generated as well as identifying the potential benefits that can be expected under Irish conditions. While the results indicate that winter wheat can be successfully established in an understorey of white clover if sown early in good conditions, competition from grass weed species represents a serious impediment to successful bi-cropping in the longer term. Consequently further research is needed before such a system can be presented to the agricultural community.
    • Improving yield and quality of forage maize.

      Crowley, J.G. (Teagasc, 1998-09-01)
      Maize silage is recognised world-wide as a high quality winter feed for livestock. Attempts to introduce the crop to Ireland in the early 1970’s failed because of the lack of suitable varieties. The release of maize varieties adapted to the colder North European and Irish climates has for the first time offered Irish beef and dairy farmers the opportunity to exploit the valuable assets of this crop. The transfer of the technology of growing maize under photodegradable polythene developed in France could further enhance the development of forage maize production in Ireland. The results presented show that the early type hybids released over the past five years are capable of producing high yields of high quality silage in selected sites across Ireland. To achieve satisfactory yields, site selection, early sowing and the use of adapted early maturing varieties is essential. Sowing maize through a photodegradable polythene film laid on the soil surface has proved successful. This technique can increase yields on average by 3.5 t/ha, increase dry matter content by 5% and starch content by ten percentage points. The system also advances maturity by approximately three weeks, guaranteeing that on most farms the maize crop will be mature and ready for harvest before the first heavy autumn frost.
    • Aspects of slurry management on pig farms.

      O'Connell-Motherway, S.; Lynch, P.B.; Carton, Owen T.; O'Toole, P. (Teagasc, 1998-09-01)
      The objectives of manure or slurry management on intensive pig farms are the provision of adequate slurry storage capacity and the efficient recycling of the slurry nutrients for crop production. However, recent surveys of pig slurry dry matter suggest there is excessive dilution of raw pig slurry with water. This has two important implications for management. The first is greater storage capacity will be required due to the increased volume of slurry generated. Slurry storage is expensive. For example, a 350 sow unit adding 10 weeks storage needs to invest £50,000. Secondly, evidence from the literature indicates an improved slurry nitrogen efficiency with the more dilute manure. The results of field trials showed that higher dry matter pig slurries reduced the relative efficiency of pig slurry nitrogen for second cut silage production. This is probably linked to reduced ammonia volatilisation losses, consequent to the less viscous nature of dilute slurry which permits a more rapid infiltration of the ammonium nitrogen into the soil. The use of a band spreader or shallow injection rather than the conventional splash plate were shown to increase the efficiency of pig slurry nitrogen for grass silage production. Therefore, the potential for the higher pig slurry dry matter, required for cost effective storage/ handling costs, to reduce the efficiency of its nitrogen for grass silage production can be partially offset by using band spreaders or shallow injection spreading systems. These have the added advantage of reducing odour emissions from the land spreading operation.