A3.1 The agriculture sector
A3.1.1 Uncertainty of animal population data
Details of the surveys and census are included to provide an understanding of the livestock statistics process and uncertainty values. The information documented is from Statistics New Zealand. Full details of the surveys are available from Statistics New Zealand’s website. See http://www.stats.govt.nz/datasets/primary-production/agriculture-production.htm for information about surveys and census before 2006 and http://www.stats.govt.nz/products-and-services/hot-off-the-press/agricultural-production/agricultural-production-statistics-final-jun07-hotp.htm for information about the 2007 census.
Agricultural production surveys
The target population for the 2007 Agricultural Production Census was all units that were engaged in agricultural production activity (including livestock, cropping, horticulture and forestry) or that owned land that was intended for agricultural activity during the year ended 30 June 2007. The response rate was 87 per cent. These businesses represent 89 per cent of the total estimated value of agricultural output. Statistics New Zealand imputes using a random “hot deck” procedure for values for farmers and growers who did not return a completed questionnaire. The imputation levels for the 2007 Agricultural Production Census are given in Table A3.1.1.
The 2007 Agricultural Production Census was not subject to sampling error. Sampling error arises from selecting a sample of businesses and weighting the results, rather than taking a complete enumeration, and is not applicable when there is a census. Non-sampling error arises from biases in the patterns of response and non-response, inaccuracies in reporting by respondents, and errors in the recording and classification of data. Statistics NZ adopts procedures to detect and minimise these types of errors, but they may still occur and are not easy to quantify.
Table A3.1.1 Imputation levels for the 2007 Agricultural Production Census
|Statistic||Percentage of total estimate imputed|
|Ewe hoggets put to ram||11|
|Breeding ewes, 2 tooth and over||12|
|Total number of sheep||12|
|Lamb born to ewe hoggets||11|
|Lambs born to ewes||11|
|Beef cows and heifers (in calf) 2 years and over||11|
|Beef cows and heifers (in calf) 1–2 years||11|
|Total number of beef cattle||11|
|Calves born alive to beef heifers/cows||11|
|Dairy cows and heifers, in milk or calf||16|
|Total number of dairy cattle||15|
|Calves born alive to dairy heifers/cows||11|
|Female deer mated||10|
|Total number of deer||10|
|Fawns born on farm and alive at 4 months||10|
|Area of potatoes harvested||9|
|Area of wheat harvested||11|
|Area of barley harvested||12|
A3.1.2 Key parameters and emission factors used in the agricultural sector
Table A184.108.40.206 Parameter values for agriculture emissions of nitrous oxide
|Parameter (Fraction)||Fraction of the parameter||Source||Parameter value|
|FracBURN||Crop residue burned in fields||Ministry of Agriculture and Forestry (expert opinion)||0.3|
|FracBURNL||Legume crop residue burned in fields||Ministry of Agriculture and Forestry (expert opinion)||0|
|FracFUEL||Livestock nitrogen excretion in excrements burned for fuel||Practice does not occur in New Zealand||0|
|FracGASF||Total synthetic fertiliser emitted as NOx or NH3||IPCC (1996) Reference Manual Table 4.19||0.1|
|FracGASM||Total nitrogen emitted as NOx or NH3||IPCC (1996) Table 4.19||0.2|
|FracGRAZ||Livestock nitrogen excreted and deposited onto soil during grazing||See Table 6.3.1||Livestock specific|
|FracLEACH||Nitrogen input to soils that is lost through leaching and run-off||Thomas et al (2002)||0.07|
|FracNCRBF||Nitrogen in N-fixing crops||IPCC (1996) Reference Manual Table 4.19||0.03|
|FracNCR0||Nitrogen in non-N-fixing crops||IPCC (1996) Reference Manual Table 4.19||0.015|
|FracR||Crop residue removed from the field as crop||IPCC (1996) Reference Manual Table 4.19||0.45|
Table A220.127.116.11 Emission factor for agriculture emissions of N2O
|EF1||Direct emissions from nitrogen input to soil||Kelliher and de Klein (2006)||0.01 kg N2O-N/kg N|
|EF2||Direct emissions from organic soil mineralisation due to cultivation||IPCC (2000) Table 4.17||8 kg N2O-N/ha-yr|
|EF3AL||Direct emissions from waste in the anaerobic lagoons AWMS||IPCC (2000) Table 4.12||0.001 kg N2O-N/kg N excreted|
|EF3SSD||Direct emissions from waste in the solid waste and drylot AWMS||IPCC (2000) Table 4.12||0.02 kg N2O-N/kg N excreted|
|EF3PRP||Direct emissions from waste in the pasture range and paddock AWMS||Carran et al (1995); Muller et al 1995; de Klein et al (2003)||0.01 kg N2O-N/kg N excreted|
|EF3OTHER||Direct emissions from waste in other AWMSs||IPCC (2000) Table 4. 13||0.005 kg N2O-N/kg N excreted|
|EF4||Indirect emissions from volatising nitrogen||IPCC (2000) Table 4.18||0.01 kg N2O-N/kg NHx-N|
|EF5||Indirect emissions from leaching nitrogen||IPCC (2000) Table 4.18||0.025 kg N2O-N/kg N leached & runoff|
Table A18.104.22.168 Emission factor for Tier 1 enteric fermentation livestock and manure management
|EFGOATS||Enteric fermentation – Goats||NZ specific||9 kg/head/yr|
|EFHORSES||Enteric fermentation – Horses||IPCC (1996) Table 4.3||18 kg/head/yr|
|EFSWINE||Enteric fermentation – Swine||IPCC (1996) Table 4.3||1.5 kg/head/yr|
|MMGOATS||Manure management – Goats||IPCC (1996) Table 4.5||0.18 kg/head/yr|
|MMHORSES||Manure management – Horses||IPCC (1996) Table 4.5||2.1 kg/head/yr|
|MMSWINE||Manure management – Swine||IPCC (1996) Table 4.6||20 kg/head/yr|
|MMPOULTRY||Manure management – Poultry||IPCC (1996) Table 4.5||0.117 kg/head/yr|
A3.2 Supplementary information for the LULUCF sector: the Land Use and Carbon Analysis System (LUCAS)
The aim of the Land Use and Carbon Analysis System (LUCAS) programme is to develop a robust and comprehensive data gathering, data management, analysis and reporting system that is consistent with IPCC good practice guidance for Land Use, Land-use Change and Forestry (GPG-LULUCF) and designed to:
be appropriate for UNFCCC LULUCF sector reporting
enable reporting under Article 3.3 of the Kyoto Protocol for the first commitment period
support and underpin New Zealand climate change policy development through to 2012 and beyond.
Data collection is separated into three components; forest, soil and land-use mapping. Data collection methodologies have been designed to provide unbiased carbon estimates at the national scale. The methods are supported by relevant scientific research. Analysis of the data will provide nationally applicable values for carbon stock and stock change for each of the five Kyoto carbon pools. The data collection methodologies and the data analysis approach are being independently reviewed to provide transparency and published in the international scientific literature to ensure the activities within the LUCAS programme are widely understood.
Natural forest permanent inventory plots have been established on a systematic eight-kilometre grid across New Zealand. Collection of the data from these plots occurred over a five-year period and was completed in early 2007. The subsequent results will determine the carbon-status of these managed forests. Currently, quality assurance and checking is on schedule to be completed by July 2009. Required re-measurement work is underway.
A planted forest carbon inventory and New Zealand-specific parameters are being developed for New Zealand to provide an unbiased estimate with known uncertainty for reporting and accounting purposes. Carbon stock estimates will be derived from plot measurements for the four biomass carbon pools. Most – around 90 per cent – of the planted forests species in New Zealand are exotic, primarily Pinus radiata.
Forests planted after the 31 December 1989
the 31 December 1989
Change in carbon stocks in forests planted after 31 December 1989 (called “post-1989 planted forests”) will be determined by measurement of trees within permanent inventory plots established on a four-kilometre grid across New Zealand. A combination of field measurements and airborne LiDAR (Light Detection and Ranging) are being used. The field measurement programme was completed at the end of 2008. LiDAR data capture occurred during February–June 2008. The LiDAR data has yet to be calibrated against the field measurements. For forest plots that are inaccessible, LiDAR data will be processed to provide the total amount of carbon per plot. The total carbon per plot will be separated into the four biomass carbon pools using a specific carbon allocation model. The measurement process will be repeated at the end of the first commitment period, based on the same set of plots. Where new forest planting covers a point on the four-kilometre grid, new plots will be established. The 2008 LiDAR mapping is already completed, while the quality assurance and checking is due to be completed by April, 2009.
Forests planted before 1 January 1990
The LUCAS programme will also establish the change in carbon stocks in New Zealand’s forests planted before 1 January 1990 – these are called pre-1990 planted forests. The post-1989 planted forest approach will be applied, but it is expected that the measurement plots will be on a coarser grid network (on an eight-kilometre grid intersects). It is planned that plot measurements will only be made in the middle of the commitment period, and will be used to forward- and back-cast carbon values to cover the five-year commitment period. Data analysis is scheduled for 2010.
Soil carbon changes very slowly in response to land-use changes. A New Zealand-specific soil carbon model is being used. Soil data for input to the model either exists from previous soil mapping programmes across New Zealand, has been collected under the natural forests work stream, or has been collected through a number of related research programmes and a specific soil sampling programme. Collation of this data and initial analysis was completed at the end of 2008. This data will allow estimates of soil carbon change where land-use changes occur. The key drivers of change are: soil type, climate, topography, and the nature of land-use change. The soils data will be analysed to identify gaps in its coverage across the country. Where significant gaps exist in important land-use areas, further samples and analysis will be performed. The quality assurance/quality checking of soil carbon changes is due to be completed by July 2009. The remaining soil deliverables are being prioritised.
The LUCAS system has been designed to achieve the following objectives in relation to land-use mapping:
determine changes in land use between 1990 and the start of the first commitment period by providing a New Zealand-wide map of land use at 1990 and at 2008
determine changes in land use through the first commitment period by providing a New Zealand-wide map of land use at 2012
determine where forests have been harvested, and where deforestation has occurred.
Land use will be mapped as per the UNFCCC categories, namely forest land, cropland, grassland, wetlands, settlements and other land.
Mapping of land use at 1990 is 99 per cent completed and is scheduled to be concluded in April 2009. The 1990 mapping uses a combination of Landsat 4 and Landsat 5, as well as some SPOT-2, satellite imagery and aerial photography. To assist in the interpretation of the 1990 imagery, land use at 2000–2001 is being determined first, and used to track land use back to 1990. The 2000–2001 mapping is using Landsat ETM+ imagery and aerial photography.
Mapping of land use at 2008 is due to be delivered by August 2009. Currently, four of 16 New Zealand regions have been mapped. Mapping of land use at 2008 will use cloud-free, SPOT-5 satellite imagery. This imagery has being captured over the 2006/07 and 2007/08 summers (November to March).
The LUCAS programme will be using medium, spatial resolution (250 m), MODIS satellite imagery to identify the location and timing of forest harvesting. The intention is to create cloud-free MODIS images of New Zealand on an annual basis. As the MODIS is not high enough to map deforestation at one hectare, the actual area of harvesting and deforestation will be determined from high resolution satellite systems or aerial photography. MODIS data will also be used to update forest changes in the 2008 land-use map, particularly those changes that occurred immediately prior to 1 January 2008.
The forest area estimates will be available for use by the New Zealand’s Emissions Trading Scheme (ETS). The ETS is the price-based mechanism established to reduce net greenhouse gas emissions below business-as-usual levels, and to comply with international obligations, including our Kyoto Protocol obligations. The forestry sector was the first sector to enter the ETS – effective 1 January 2008. It is expected that LUCAS-derived, forest area estimates will be used to verify applications to the Forestry ETS and to establish whether deforestation is being satisfactorily reported by forest-land owners.
A component of the LUCAS programme is the development of a database to store and manipulate all data. The modular database system will achieve the following objectives:
provide a transparent system for data and calculations
provide a repository for the storing, versioning and validation of plot measurements
store static land-use layers and LUCAS-derived polygon layers to determine land use and land-use change area nationally
calculate carbon stocks per hectare for land uses and soils based on the plot and spatial data collected
produce the common reporting format reports for the LULUCF sector and reporting under Article 3.3 of the Kyoto Protocol.
The calculation and reporting application is under development.
A3.2.3 Statistical design and uncertainty
The statistical methods and assumptions will be independently reviewed to ensure they are consistent with best practice statistical design. Opportunities for ongoing improvement of data collection systems will be sought, while considering the cost-effectiveness of alternatives.
Uncertainty in estimated carbon values will be determined as the data collection, land-use mapping and analysis approaches are developed. The uncertainty information will be used to prioritise future improvements in methodologies and data collection.
A3.2.4 Quality Assurance
A quality assurance framework has being developed for the LUCAS project. This is being implemented across all LUCAS activities. It is consistent with New Zealand’s greenhouse gas inventory QAQC plan and with IPCC good practice guidance (IPCC, 2000 and 2003).