• Beef production from feedstuffs conserved using new technologies to reduce negative environmental impacts

      O'Kiely, Padraig; Crosson, Paul; Hamilton, William J.; Little, Enda; Stacey, Pamela; Walsh, Karl; Black, Alistair D; Crowley, James C.; Drennan, Michael J; Forristal, Dermot; et al. (Teagasc, 2007-12-01)
      Most (ca. 86%) Irish farms make some silage. Besides directly providing feed for livestock, the provision of grass silage within integrated grassland systems makes an important positive contribution to effective grazing management and improved forage utilisation by grazing animals, and to effective feed budgeting by farmers. It can also contribute to maintaining the content of desirable species in pastures, and to livestock not succumbing to parasites at sensitive times of the year. Furthermore, the optimal recycling of nutrients collected from housed livestock can often be best achieved by spreading the manures on the land used for producing the conserved feed. On most Irish farms, grass silage will remain the main conserved forage for feeding to livestock during winter for the foreseeable future. However, on some farms high yields of whole-crop (i.e. grain + straw) cereals such as wheat, barley and triticale, and of forage maize, will be an alternative option provided that losses during harvesting, storage and feedout are minimised and that input costs are restrained. These alternative forages have the potential to reliably support high levels of animal performance while avoiding the production of effluent. Their production and use however will need to advantageously integrate into ruminant production systems. A range of technologies can be employed for crop production and conservation, and for beef production, and the optimal options need to be identified. Beef cattle being finished indoors are offered concentrate feedstuffs at rates that range from modest inputs through to ad libitum access. Such concentrates frequently contain high levels of cereals such as barley or wheat. These cereals are generally between 14% to 18% moisture content and tend to be rolled shortly before being included in coarse rations or are more finely processed prior to pelleting. Farmers thinking of using ‘high-moisture grain’ techniques for preserving and processing cereal grains destined for feeding to beef cattle need to know how the yield, conservation efficiency and feeding value of such grains compares with grains conserved using more conventional techniques. European Union policy strongly encourages a sustainable and multifunctional agriculture. Therefore, in addition to providing European consumers with quality food produced within approved systems, agriculture must also contribute positively to the conservation of natural resources and the upkeep of the rural landscape. Plastics are widely used in agriculture and their post-use fate on farms must not harm the environment - they must be managed to support the enduring sustainability of farming systems. There is an absence of information on the efficacy of some new options for covering and sealing silage with plastic sheeting and tyres, and an absence of an inventory of the use, re-use and post-use fate of plastic film on farms. Irish cattle farmers operate a large number of beef production systems, half of which use dairy bred calves. In the current, continuously changing production and market conditions, new beef systems must be considered. A computer package is required that will allow the rapid, repeatable simulation and assessment of alternate beef production systems using appropriate, standardised procedures. There is thus a need to construct, evaluate and utilise computer models of components of beef production systems and to develop mathematical relationships to link system components into a network that would support their integration into an optimal system model. This will provide a framework to integrate physical and financial on-farm conditions with models for estimating feed supply and animal growth patterns. Cash flow and profit/loss results will be developed. This will help identify optimal systems, indicate the cause of failure of imperfect systems and identify areas where applied research data are currently lacking, or more basic research is required.
    • Changes in yield and composition of barley, wheat and triticale grains harvested during advancing stages of ripening

      Stacey, Pamela; O'Kiely, Padraig; Hackett, Richard; Rice, B.; O'Mara, Frank P.; Teagasc Walsh Fellowship Programme (Teagasc, Oak Park, Carlow, Ireland, 2006)
      This study involved an evaluation of the changes in grain yield, nutritive value, ensilability and harvesting losses of intensively managed winter cereals harvested during the advancing stages of ripening. Five cereal crops (barley cv. Regina and wheat cv. Madrigal in 2001; barley cv. Regina, wheat cv. Falstaff and triticale cv. Fidelio in 2002) were assessed. Twenty plots per crop were arranged in a randomised complete block design, with five times of harvest (four for barley in 2002) and four replicate blocks per harvest. Dry matter (DM) yields changed relatively little between harvest dates, but fresh yields declined (P < 0.001) over time due to the moisture loss associated with ripening. Time-course changes in indices of nutritive value, such as concentrations of crude protein, starch and ash, and organic matter digestibility, were relatively small and did not follow a consistent pattern. Ensilability indices, such as DM and watersoluble carbohydrate concentrations and buffering capacity, indicated that satisfactory fermentations were likely if such crops were ensiled; buffering capacity, generally declining with advancing maturity. Harvesting losses were not clearly related to growth stage at harvest. It is concluded that winter cereal grain (barley, wheat and triticale) DM yields and quality were relatively constant as ripening progressed from DM concentrations of around 550 to >800 g/kg.
    • A comparison of husked and naked oats under Irish conditions

      Hackett, Richard (Teagasc (Agriculture and Food Development Authority), Ireland, 2018-02-22)
      During the harvesting of husked oats (Avena sativa L.), the kernel remains tightly enclosed by a lignified lemma and palea, collectively termed the husk or hull. In naked oats, which are the same species as husked oats, the lemma is much less lignified and the kernel threshes free during harvesting. The absence of the largely indigestible husk increases the nutritive value of naked oats compared to that of husked oats, particularly for non-ruminants and poultry. There is little information regarding the potential of naked oats as an arable crop in Ireland. The objective of this study was to determine the productivity of naked oats under Irish conditions. Field experiments were carried out in the south east of Ireland to compare the grain yield and grain quality of both autumn-sown and spring-sown naked and husked oat cultivars. Grain yield of naked oat cultivars was significantly lower than that of husked oat cultivars, irrespective of whether they were autumn sown or spring sown. However, when the kernel yield of husked oat cultivars was estimated, differences in yield between the two types were much smaller, and in some cases, kernel yield of naked oat cultivars exceeded that of husked oat cultivars. Grain quality, as indicated by hectolitre weight and grain N concentration, was generally greater for naked oat cultivars than for husked oat cultivars. It is concluded that under Irish conditions, naked oats have the potential to produce kernel yields equivalent to husked oats. The grain produced is of high quality and may be particularly suited for the nutrition of non-ruminants.
    • Effect of nitrogen fertilizer application timing on nitrogen use efficiency and grain yield of winter wheat in Ireland.

      Efretuei, A.; Gooding, M.; White, E.M.; Spink, John; Hackett, Richard (Teagasc (Agriculture and Food Development Authority), Ireland, 2016-12-01)
      The objectives of this work were to determine the effects of initiating application of fertilizer nitrogen (N) to winter wheat at different growth stages (GSs) on grain yield and N use efficiency (NUE). A factorial experiment was carried out in two growing seasons (2011 and 2012) with five timings of first N application (GS 24/26 [tillering], GS 30, GS 31, GS 32 or GS 37) and an unfertilized control, two sowing densities (100 and 400 seeds/m2) and a cattle slurry treatment (with or without slurry). The latter was included to simulate variation in soil N supply (SNS). Delaying the first application of N from the tillering stage until GS 30 had no significant effect on grain yield in either year. Further delaying the initial N application until GS 31 caused a significant yield reduction in 2011, in comparison to GS 30 application, but not in 2012. Differences in efficiency of recovery and use of fertilizer N by the crop among the first three application timings were small. There was no evidence to support alteration in the timing of the first application of N in response to low plant density. Slurry application did not influence SNS, so the interaction between SNS and fertilizer N application timing could not be determined. It is concluded that in order to maximise yield and NUE, the first N application should be applied to winter wheat between late tillering and GS 30 and that delaying the first N until GS 31 can lead to yield reductions compared to the yield obtained with earlier application.
    • Effects of over-winter green cover on groundwater nitrate and dissolved organic carbon concentrations beneath tillage land

      Premrov, Alina; Coxon, Catherine E.; Hackett, Richard; Kirwan, Laura; Richards, Karl G. (Elsevier, 13/09/2012)
      Application of over-winter green cover (e.g. cover crops) as a measure for reducing nitrate losses from tillage land has been frequently investigated, especially in the unsaturated zone. Monitoring of groundwater is less common in these studies. Studies on groundwater responses to different land treatments can be challenging because they can be influenced by various conditions, such as recharge, seasonal variations, and aquifer properties, often occurring at different time scales than surface water processes. The aim of this study was to evaluate groundwater nitrate (NO3−single bondN) and dissolved organic carbon (DOC) concentration responses to different over-winter green covers: mustard, natural regeneration and no cover. A field experiment was designed and run for three years on tillage land underlain by a vulnerable sand and gravel aquifer in the south-east of Ireland. Results showed that over-winter green cover growth on tillage land can be an effective measure to reduce groundwater NO3−single bondN concentrations. A significant decrease in groundwater NO3−single bondN concentrations was observed under the mustard cover compared to no cover. All treatments, including no cover, showed a decline in groundwater NO3−single bondN concentrations over time. A significant increase in groundwater DOC was also observed under the mustard cover. Although the overall groundwater DOC concentrations were low, the increased DOC occurrence in groundwater should be accounted for in carbon balances and could potentially enhance groundwater denitrification in cases where aquifer conditions may favour it.
    • Mustard catch crop enhances denitrification in shallow groundwater beneath a spring barley field

      Jahangir, Mohammad M. R.; Minet, E.; Johnston, Paul; Premrov, Alina; Coxon, Catherine E.; Hackett, Richard; Richards, Karl G.; Department of Agriculture, Food and the Marine, Ireland; RSF 06383 (Elsevier, 26/12/2013)
      Over-winter green cover crops have been reported to increase dissolved organic carbon (DOC) concentrations in groundwater, which can be used as an energy source for denitrifiers. This study investigates the impact of a mustard catch crop on in situ denitrification and nitrous oxide (N2O) emissions from an aquifer overlain by arable land. Denitrification rates and N2O-N/(N2O-N + N2-N) mole fractions were measured in situ with a push–pull method in shallow groundwater under a spring barley system in experimental plots with and without a mustard cover crop. The results suggest that a mustard cover crop could substantially enhance reduction of groundwater nitrate NO3--N via denitrification without significantly increasing N2O emissions. Mean total denitrification (TDN) rates below mustard cover crop and no cover crop were 7.61 and 0.002 μg kg−1 d−1, respectively. Estimated N2O-N/(N2O-N + N2-N) ratios, being 0.001 and 1.0 below mustard cover crop and no cover crop respectively, indicate that denitrification below mustard cover crop reduces N2O to N2, unlike the plot with no cover crop. The observed enhanced denitrification under the mustard cover crop may result from the higher groundwater DOC under mustard cover crop (1.53 mg L−1) than no cover crop (0.90 mg L−1) being added by the root exudates and root masses of mustard. This study gives insights into the missing piece in agricultural nitrogen (N) balance and groundwater derived N2O emissions under arable land and thus helps minimise the uncertainty in agricultural N and N2O-N balances.
    • Predicting soil moisture conditions for arable free draining soils in Ireland under spring cereal crop production

      Premrov, Alina; Schulte, Rogier P.; Coxon, Catherine E.; Hackett, Richard; Richards, Karl G. (Teagasc, 2010)
      Temporal prediction of soil moisture and evapotranspiration has a crucial role in agricultural and environmental management. A lack of Irish models for predicting evapotranspiration and soil moisture conditions for arable soils still represents a knowledge gap in this particular area of Irish agro-climatic modelling. The soil moisture deficit (SMD) crop model presented in this paper is based on the SMD hybrid model for Irish grassland (Schulte et al., 2005). Crop and site specific components (free-draining soil) have been integrated in the new model, which was calibrated and tested using soil tension measurements from two experimental sites located on a well-drained soil under spring barley cultivation in south-eastern Ireland. Calibration of the model gave an R2 of 0.71 for the relationship between predicted SMD and measured soil tension, while model testing yielded R2 values of 0.67 and 0.65 (two sites). The crop model presented here is designed to predict soil moisture conditions and effective drainage (i.e., leaching events). The model provided reasonable predictions of soil moisture conditions and effective drainage within its boundaries, i.e., free-draining land used for spring cereal production under Irish conditions. In general, the model is simple and practical due to the small number of required input parameters, and due to model outputs that have good practical applicability, such as for computing the cumulative amount of watersoluble nutrients leached from arable land under spring cereals in free-draining soils.
    • Response of two-row and six-row barley to fertiliser N under Irish conditions

      Hackett, Richard (Teagasc (Agriculture and Food Development Authority), Ireland, 2016-12-30)
      A range of cultivar types, including two-row and six-row types as well as line and hybrid types, are used for winter barley production in Ireland. There is little information available on the fertiliser nitrogen (N) requirements or the N use efficiency of these different types, particularly under Irish conditions. The objectives of the work presented here were to compare the response to fertiliser N of a two-row line cultivar, a six-row line cultivar and a six-row hybrid cultivar in terms of grain yield and aspects of N use efficiency. Experiments were carried out over three growing seasons, in the period 2012-2014, on a light-textured soil comparing the response of the three cultivars of winter barley to fertiliser N application rates ranging from 0 to 260 kg N/ha. There was no evidence that cultivar type, regardless of whether it was a two-row or six-row line cultivar or a six-row hybrid cultivar, influenced the response to fertiliser N of winter barley. There were some indications that six-row cultivars were less efficient at recovering soil N but used accumulated N more efficiently than the two-row cultivar. This work provided no evidence to support adjustment of fertiliser N inputs to winter barley based on cultivar type