Know your numbers

Your greenhouse gas 'numbers' are the biogenic methane and nitrous oxide emissions coming from your farm from livestock production and nitrogen fertiliser use. 

Knowing your numbers tells you what your current agricultural greenhouse gas emissions are and, importantly, what is driving them in your farm system. Knowing this will help you develop a plan to manage those emissions. 

The sooner you find out your farm's greenhouse gas numbers, the sooner you can start to understand where those emissions come from and what actions might be possible to manage or reduce them on your farm. This enables you to plan ahead for when those emissions will be priced. 

There are currently two definitions of a farm being used - one for the 'knowing your numbers and having a plan' requirements and one for the pricing system itself. 

There are several different ways that you can find out your farm's greenhouse gas numbers:

1. Use a tool or calculator to do it yourself
2. Ask your farm advisor which tool/s they use and what services they can offer you in this area
3. Ask your processing company or industry organisation for advice. Some are moving into this area, including providing these numbers for their farmers (see below). 

Tools and calculators

A variety of tools for estimating agricultural greenhouse gas emissions at the farm level are available. These range in complexity and cost from simple, quick and freely available calculators to more detailed quantitative tools that might also require assistance from a farm advisor in order to access and/or interpret the results. Some of these tools are also specific to a particular farm type. 

All of the tools are likely to produce a different number as they use slightly different (but valid) approaches to calculating emissions. The important thing is to use the same tool to track your emissions over time. This enables you to make connections between on-farm management and emissions in relation to your system. 

The He Waka Eke Noa partnership assessed the suitability of different tools for calculating a farm's greenhouse gas numbers. The following thirteen were assessed (in alphabetical order): 

• Alltech has a proprietary carbon footprint service 'E-CO2' for businesses.
• Beef + Lamb NZ has developed a GHG Calculator - a free online tool for farmers to measure and report on-farm greenhouse gas emissions and sequestration, reflecting the individual farm's livestock and production systems.
• E2M is an enviro-economic model operated by Grazing Systems Limited that is based on a linear-programming platform and can model whole farm systems including greenhouse gas emissions.
• Farmax is a decision-support tool for pastoral farmers that incorporates productivity and profitability data and now includes a greenhouse gas component. 
• Fonterra is using the Agricultural Inventory Model (AIM) to provide estimates of on-farm emissions for all its suppliers. AIM underpins the New Zealand Greenhouse Gas Inventory. 
• Horticulture New Zealand has a nitrous oxide emissions spreadsheet developed by (and available from) MPI for its growers.
• Made for Good RX is a free tool for suppliers to the New Zealand Merino Company to help calculatre on-farm emissions and transition to regenerative production systems.
• The Ministry for the Environment has a spreadsheet calculator for New Zealand businesses, including farms, to work out their greenhouse gas numbers.
• MyImprint is a proprietary model, based on the New Zealand greenhouse gas inventory. It can model farms that have sheep, beef, deer and dairy cattle and includes forestry sequestration.
• OverseerFM is a software platform for modelling nutrient flows through a farm and includes a greenhouse gas component. 
• The PigGas NZ Calculator has been developed to provide pork producers and advisors with a tool to estimate carbon dioxide equivalent emissions within the boundary of a piggery enterprise. 
• ProductionWise is a crop record-keeping and decision support tool developed by the Foundation for Arable Research (FAR) that now generates greenhouse gas numbers for arable systems. 
• Toitū Envirocare offers a tool that builds on greenhouse gas data from OverseerFM to provide an ISO certifiable carbon footprint of a farm. 

You can find out more about these tools in two independent reports prepared by AgFirst for He Waka Eke Noa. As more tools are available, they will also be assessed and the findings made public. 

NOTE: The tools listed on this page have been endorsed for use in meeting the legislated milestones for farmers and growers to know their greenhouse gas numbers. However, they will not be the tool used in the farm-level pricing system that will apply from 2025. For that, it is proposed to use a single calculator for all farms - a simplified one by 2025 and a more sophisticated one by 2028. More will be known on that as the work is completed. 

At a basic level, annually, you will need to know:

• Livestock numbers by stock type/s, either using monthly values or (for simple tools) a weighted annual average 
• Amount of synthetic nitrogen fertiliser applied

Additional data that can support a more detailed estimation of greenhouse gas numbers includes: 

• Farm size - total and effective areas 
• Livestock class, age, number and movements
• Production data such as total kg milk solids, liveweight or crop yield, and percentage share of revenue 
• Purchased feed
• Nitrogen fertiliser or lime applications, including product type, rate and timing 

NOTE: Different tools will give you different numbers. This is because the models that sit underneath them rely on different values, depending on their complexity. For example, while simpler tools are relatively quick to complete, they rely on national/international default values for estimating methane and nitrous oxide. This typically results in a less accurate farm-scale greenhouse gas footprint, but is useful for generating a quick estimate. 

A more detailed tool can take longer to complete and will require more detailed data (e.g. feed types and N content, dry matter intake, metabolisable energy, animal liveweights, replacement rates etc), but will better reflect farm-scale emissions (and reductions). 

Farm plans are used to help bring natural resources, management, people, animals and business together. They are individual to each farm and are an important tool to help farmers manage their land in an environmentally and financially sustainable way. Many farmers already have a farm plan in place, often this has been done for managing water quality.

The He Waka Eke Noa partnership agreed that a farm planning approach would help the sector achieve a net reduction in agricultural greenhouse gas emissions if farmers and growers need to have a written plan in place to measure and manage their greenhouse gas emissions. 

To keep things simple, the intent would be to add a greenhouse gas 'module' to existing farm plans, such as those required by regional councils, processor programmes, fertiliser company plans and irrigation scheme programmes.  

This greenhouse gas module will include: 

1. Knowing your farm's greenhouse gas numbers
2. Identifying opportunities to reduce your farm's greenhouse gas emissions and capture carbon 
3. Choosing which actions you could implement in your system
4. Keeping records, monitoring and reviewing progress

If you are a dairy farmer: 

If you are part of Synlait Lead with Pride, Miraka Te Ara Miraka, Tatou 360 or Fonterra Tiaki programmes, these will align with the He Waka Eke Noa greenhouse gas module requirements from 2021. 

Other dairy company programmes will be modified to include a greenhouse gas module. 

If you are a grower: 

If you are an arable grower, the Foundation for Arable Research Farm Environment Plan template should be used. 

If you are a fruit or vegetable grower, the Good Agricultural Practice (GAP) Environmental Management System (EMS) add-on can be used for greenhouse gas module requirements.  

If you are a sheep, beef or deer farmer: 

Beef + Lamb NZ has launched its new farm plan template, which includes a climate change module. Deer farmers may also wish to talk to Deer Industry New Zealand. 

Processing companies are also looking to start rolling out New Zealand Farm Assurance Programme Plus (NZFAP Plus) in 2021, which should also be able to be used to meet the greenhouse gas module requirements. 

If you run a multi-sector farming enterprise: 

Many farmers and growers in New Zealand are multi-sector, growing and supplying crops and livestock for different purposes and to different processors. Some have multiple farms that are spread across one or more regions. 

You can decide how a greenhouse gas module for your farm plan is best prepared and reported on. Some of the farm plan delivery programmes listed above are cross-sector and can account for multiple farms. If you have a focus in one sector, e.g. sheep and beef, you can choose one of these programmes to complete your greenhouse gas module. 

Whichever pathway you chose, please tell the different farm plan delivery programmes that you belong to how you will complete your greenhouse gas module. This will help with reporting.

If you are not in a farm plan delivery programme:

You can talk to the industry organisation that best suits your farming system.

If the He Waka Eke Noa milestones aren't met, it's possible that the programme won't be considered successful. This means agriculture could be brought into the ETS at the processor level instead.