An analysis of environmental and economic implications of nil and restricted grazing systems designed to reduce nitrate leaching from New Zealand dairy farms. II. Pasture production and cost/benefit analysis

Klein, Cecile A. M. de

doi:10.1080/00288233.2001.9513479

Cited by 33 publications

(12 citation statements)

References 42 publications

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“…Home-grown forage is the lowest cost feed source for dairy farms in both Australia and New Zealand, and utilisation of this resource provides much of the competitive ability of these nations on the international dairy market (Chapman et al 2009). Close matching of the growth curve of pasture crops, such as ryegrass, to the feeding requirements of grazing dairy cattle can provide significant economic and production benefits to farmers, through reduced reliance on supplementary feeding over summer, autumn and winter, and diminished excess pasture production and related management costs over late spring (Chapman et al 2009; de Klein 2001; Rawnsley et al 2013; Stewart and Hayes 2011). Combination of the seasonal biomass prediction equations with recently developed economic values for seasonal biomass (Chapman et al 2012) will enable the effective implementation of economic value selection indexes to assist in breeding and selection decisions.…”

Section: Discussionmentioning

confidence: 99%

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass

Pembleton

Inch²,

Baillie

et al. 2018

Theor Appl Genet

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Key messageExploitation of data from a ryegrass breeding program has enabled rapid development and implementation of genomic selection for sward-based biomass yield with a twofold-to-threefold increase in genetic gain.AbstractGenomic selection, which uses genome-wide sequence polymorphism data and quantitative genetics techniques to predict plant performance, has large potential for the improvement in pasture plants. Major factors influencing the accuracy of genomic selection include the size of reference populations, trait heritability values and the genetic diversity of breeding populations. Global diversity of the important forage species perennial ryegrass is high and so would require a large reference population in order to achieve moderate accuracies of genomic selection. However, diversity of germplasm within a breeding program is likely to be lower. In addition, de novo construction and characterisation of reference populations are a logistically complex process. Consequently, historical phenotypic records for seasonal biomass yield and heading date over a 18-year period within a commercial perennial ryegrass breeding program have been accessed, and target populations have been characterised with a high-density transcriptome-based genotyping-by-sequencing assay. Ability to predict observed phenotypic performance in each successive year was assessed by using all synthetic populations from previous years as a reference population. Moderate and high accuracies were achieved for the two traits, respectively, consistent with broad-sense heritability values. The present study represents the first demonstration and validation of genomic selection for seasonal biomass yield within a diverse commercial breeding program across multiple years. These results, supported by previous simulation studies, demonstrate the ability to predict sward-based phenotypic performance early in the process of individual plant selection, so shortening the breeding cycle, increasing the rate of genetic gain and allowing rapid adoption in ryegrass improvement programs.Electronic supplementary materialThe online version of this article (10.1007/s00122-018-3121-7) contains supplementary material, which is available to authorized users.

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Section: Discussionmentioning

confidence: 99%

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass

Pembleton

Inch²,

Baillie

et al. 2018

Theor Appl Genet

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“…The restricted grazing policies evaluated here were based on practical considerations, ease of implementation, and allowing enough grazing time for high‐producing animals to maintain pasture intake. This explains why the total cow hours on the standoff facility were smaller than other studies (see de Klein, 2001; de Klein et al; 2006; Ledgard et al, 2006; Christensen et al, 2012). Consequently, the amount of reduction in N leaching that can be expected from restricted grazing will vary considerably between cases.…”

Section: Discussionmentioning

confidence: 71%

Combining Restricted Grazing and Nitrification Inhibitors to Reduce Nitrogen Leaching on New Zealand Dairy Farms

et al. 2017

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Intensification of pastoral dairy systems often means more nitrogen (N) leaching. A number of mitigation strategies have been proposed to reduce or reverse this trend. The main strategies focus on reducing the urinary N load onto pastures or reducing the rate of nitrification once the urine has been deposited. Restricted grazing is an example of the former and the use of nitrification inhibitors an example of the latter. A relevant concern is the cost effectiveness of these strategies, independently and jointly. To address this concern, we employed a modeling approach to estimate N leaching with and without the use of these mitigation options from a typical grazing dairy farm in New Zealand. Three restricted grazing options were modeled with and without a nitrification inhibitor (dicyandiamide, DCD) and the results were compared with a baseline farm (no restricted grazing, no inhibitor). Applying DCD twice a year, closely following the cows after an autumn and winter grazing round, has the potential to reduce annualized and farm-scale N leaching by ∼12%, whereas restricted grazing had leaching reductions ranging from 23 to 32%, depending on the timing of restricted grazing. Combining the two strategies resulted in leaching reductions of 31 to 40%. The abatement cost per kilogram of N leaching reduction was NZ$50 with DCD, NZ$32 to 37 for restricted grazing, and NZ$40 to 46 when the two were combined. For the range analyzed, all treatments indicated similar cost per percentage unit of mitigated N leaching, demonstrating that restricted grazing and nitrification inhibitors can be effective when used concurrently.

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“…This GJ total has a value of US$115,714,194 at US$12.18 GJ −1 (2016 values; http://ramblingsdc.net/EnCalcs.html). A loss of 8% of land used to produce pasture if yielding 18.5 t DM ha −1 yr −1 from 200 kg N ha −1 yr −1 29 would equate to a reduction of 325,600 t of pasture DM or 23,257,143 kg milk solids (MS) yr −1 at a ratio of 14:1 DM consumed to MS produced (http://www.sciquest.org.nz/node/40615). At US$3.6 kg −1 MS, the present low value of MS gives US$83,260,571 (2016 values), representing a net gain of US$32,453,622 in the Mxg plots.…”

Section: Discussionmentioning

confidence: 99%

Delivery of multiple ecosystem services in pasture by shelter created from the hybrid sterile bioenergy grass Miscanthus x giganteus

Littlejohn

Hofmann

Wratten

2019

Sci Rep

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The benefits of shelter in increasing crop yields and accelerating ripening has been well researched in fruit, arable and horticultural crops. Its benefits to pasture, despite its importance for livestock production, is less well researched. In this work, Miscanthus shelterbelts were established on an intensively irrigated dairy farm. Seven key ecosystem services associated with these belts were identified and quantified. Pasture yield and quality were recorded in Miscanthus -sheltered and control field boundaries with little shelter. Pasture yield increased by up to 14% in the sheltered areas downwind of Miscanthus . Pasture quality was equivalent in the sheltered and open areas. Miscanthus provided more favourable nesting sites for bumblebees and for New Zealand endemic lizards (skinks) compared to field boundaries. The sheltered areas also had higher mineralisation rates of organic matter and higher numbers of earthworms. Using a high-yielding sterile grass such as Miscanthus to deliver a wide range of ecosystem services also produced a bioenergy feedstock. In conclusion, full benefits of shelterbelts to the farming system cannot be fully assessed unless direct and indirect benefits are properly assessed, as in this work.

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An analysis of environmental and economic implications of nil and restricted grazing systems designed to reduce nitrate leaching from New Zealand dairy farms. II. Pasture production and cost/benefit analysis

Cited by 33 publications

References 42 publications

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass

Exploitation of data from breeding programs supports rapid implementation of genomic selection for key agronomic traits in perennial ryegrass

Combining Restricted Grazing and Nitrification Inhibitors to Reduce Nitrogen Leaching on New Zealand Dairy Farms

Delivery of multiple ecosystem services in pasture by shelter created from the hybrid sterile bioenergy grass Miscanthus x giganteus

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