Future scenarios for arable agriculture

Exploring food security, emission reduction and alternative protein production scenarios.

University of Canterbury, Manaaki Whenua Landcare research, Foundation for Arable Research

Know more about our work:

Our Decision Support Tool

National scale scenarios

Livestock sector scenarios

Regional scenarios

Overview

Agriculture in New Zealand has entered a period of significant disruption due to impacts from change drivers, such as climate, trade agreements, socio-economic parameters, diet, food trends, disease or pandemic and emerging technologies or biotechnologies. Consequently, the arable sector, as a pillar of the agricultural system, needs to be transformed and strengthened to help achieve Carbon Neutrality and profitability objectives.

According to the Minsitry of Primary Industries ( 2022 ), the arable sector has faced a challenging season and difficult harvest in 2022 impacting crop yields and quality. Consequently, it is expected to decrease the total arable export value by 2% in 2022 and 6% 2023.

"The 2021/22 season is being ranked by growers as one of the worst on record. The unprecedented wet season caused yield reductions to crops in Canterbury and parts of the North Island."

Ministry for Primary Industry (SOPI 2021)

Our work aims to develop scenarios at the national to regional scale for assessing pathways and interventions to underpin strategy initiatives related to arable agriculture. Food security, tackling climate change (emissions reduction), and developing alternative protein options in New Zealand are three threads that we have explored.

Māori and Stakeholder Engagement

This work has been carried out in partnership with Tipene Merritt (Ngāti Kauwhata, Rangitāne, Ngāpuhi & Ngāi Te Rangi, Kaiārahi Rangahau Māori for Science and Engineering ), as well as stakeholders from the arable sector (i.e. Foundation for Arable Research ), to develop and simulate disruptive scenarios and analyse consequences on land-use change, resilience, sustainability and profitability.

Further to the working relationship with Kā Waimaero/Ngāi Tahu Centre, Tipene has engaged with Māori communities in the Bay of Islands and Tauranga regions. He also facilitated a workshop with representatives from the Ministry for the Environment. Listen to Tipene talking about Māori engagement.

Tipene Merritt is talking about Māori engagement in an Our Land and Water project 2022

The Foundation for Arable research, represented by Ivan Lawrie, has defined the main line of the scenarios of interests. Listen to Ivan talking about the FAR engagement process and the arable sector's interest in three major topics: wheat self-sufficiency in Aotearoa, playing a key role in tackling climate change, growing plant protein for a more sustainable future.

Ivan Lawrie from FAR is talking about the arable sector implication - Our Land and Water 2022

Scenario quantification

We explored three different pathways and interventions for increasing the profitability, resilience, and sustainability of arable agriculture in Aotearoa over the next 5-30 years.

Food security: increasing wheat production to gain self sufficiency (scenario 1)

In this scenario, the NZ wheat production is increased significantly. The objective is to reach self sufficiency in New Zealand and gain cereal food security for all New Zealanders.

In 2022: there were 250,000 tonnes shortfall for human and animal consumption in NZ.
Objective: reach 700,000 tonnes produced per year.

A side impact of increasing grain production is increasing storage and infrastructure. Growing grains with the help of the Dairy sector, for example, will require more contractors (work force), machinery, and may raise irrigation pressure points during key growth stages.

Two main levers of action were explored: increasing the area of production and enhancing yields.

Questions the Decision Support Tool can answer:

What is the yield/area balance to grow 700,000 tonnes of wheat in NZ?
What are the economic and environmental ramifications?
If all Canterbury dairy farms grow 1 to 5% of cereals, do we achieve grain self-sufficiency?

Mitigating climate change: reducing nitrogen and methane emissions (scenario 2)

The Zero Carbon Amendment Act has set reduction targets of:

Net zero for carbon dioxide and nitrous oxide by 2050.
-24 to -47% below 2017 levels of biogenic methane to by 2050, including -10% below 2017 levels by 2030. CO₂ equivalent emissions from CH₄ in 2017 were 23,400 Gigagrams . Objectives are to reach between 12,400 Gg to 17,700 Gg CO₂ eq from methane.

New Zealand research and technology development to reduce methane emissions from agriculture and livestock is promising. It includes research programmes on breeding, feeds, inhibitors, vaccine, manure and science of methane. Mitigation options and management strategies like alternative forages introduced in animal diet can significantly reduce the nitrogen emissions on farm.

In this scenario, we apply known benefits of alternative forage and grain diets to dairy and beef cattle to reduce methane and nitrogen emissions. According to recent studies ( LGGF report , Jonker et al. 2017, Sun et al., 2016 ), feeding cows at least 20% and up to 50% of their diet with brassicas can mitigate methane emissions from rumen of about 30%, and introducing alternative forage and low nitrogen feed in livestock diet could reduce N₂O emissions by 25% ( de Klein et al., 2020 ; Ledgard et al., 2019 ).

A side impact of increasing brassica and grain productions is also increasing storage, infrastructure, and the need for a larger work force.

Two main levers tested in this scenario were: the number of cows (dairy and beef cattle) and a significant change in animals' diet.

Questions the Decision Support Tool can answer:

How many hectares of alternative forages, forage grains, other grains, do farmers need to grow in order to reach the government methane emission objectives?
How much does planting brassicas and grains contribute to the nitrogen emission reduction?
What number of animals is sustainable to reach the government methane reduction objective?

Alternative proteins: developing a pea and fava bean protein market in NZ (scenario 3)

Plant based protein production is an evolving area. A recent report estimates one in every 10 protein products sold in 2035 will come from alternative protein sources. With investment in the plant protein extraction market, New Zealand has the capacity to grow and transform pea and fava bean protein on site and create a 100% NZ label ( FAR, PWC report ). Developing a plant based protein market is also consistent with The Climate Change Commission’s recommendations to Government to reduce the size of the dairy, sheep and beef herds by 14% by 2030. Growing plant based and alternative proteins will lead to a reduction in nitrogen fertilisers and water use for irrigation, as compared to pasture production for dairying.

This scenario analyses the development of land use, management, value chain and market opportunities from alternative protein production.

Questions the Decision Support Tool can answer:

How many hectares of pea and fava beans are required to produce 10% of New Zealand's protein needs?
What are the economic and environmental ramifications of this production?
What price is required to incentivise farmers to grow peas/beans and make a sustainable profit?

Decision Support Tool

We have developed an assessment tool to explore different pathways and interventions for increasing the profitability, resilience, and sustainability of agriculture in New Zealand over the next 5-30 years. This user-friendly interface makes it possible to explore scenarios related to the development of a particular crop, changes to the whole sector, the evolution of prices, changes in yields, as well as the environmental effects of changes in agricultural practices (fertilization, irrigation, livestock feed).

Try the DST online

Know more about the DST

Read the publication

Listen to Pr Tom Cochrane, explaining in a video tutorial the DST interface, to learn using the model.

Arable model tutorial by Pr Tom Cochrane.

The interactive DST is accessible below. The default data is 2021, sourced from AFIC , StatsNZ and FAOSTAT. Users can then modify the "Arable production inputs" and the "Technology and mitigation options" values according to their simulation or scenario requirements. The model the produces outputs on calories, proteins, irrigation water use, emissions, and export values.

Disclaimer: this Decisions Support Tool (Tool) is in beta form and is provided to users for testing and evaluation purposes only. The Tool may contain gaps, errors or inaccuracies and may not function in the same manner as commercially available products. Users of the Tool acknowledge and agrees that the Tool is provided by the University of Canterbury (UC) and Manaaki Whenua – Landcare Research (MWLR) on an “as is” basis without any warranty of any kind. UC and MWLR assumes no liability for any loss or damage arising from how a user chooses to use the Tool or any information derived from it, including for any decision making or other commercial or regulatory purpose.

Results

Scenario 1

Food security: increasing wheat production to gain self sufficiency

Two main levers have been tested to grown 700,000 tonnes of wheat in New Zealand: increase production area and increase yields. To illustrate the effect of multiple bad weather seasons (either droughts or very wet springs), one simulation showing lower yields than 2021 was run.

Results in the figure below show the need to grow significantly more wheat area to achieve grain self-sufficiency. Keeping the current average yield of 9.9 t/ha, or improving it to 12 t/ha (by using widely the technology of precision agriculture) will require an extra 13k to 25k hectares of wheat.

Irrigation water used requirement, if current irrigation standards are applied (i.e. a mean of 295 mm/year for wheat production) would increase by 8 to 30.5%. CO₂ equivalent emissions from Nitrogen (i.e. 267 Gg CO₂eq estimated in 2021) would increase by 9.3 to 31.8%. However, introducing this wheat production in a livestock system (i.e. Dairy) would have a positive impact, producing almost 8 times less CO₂-e biogenic emissions and using one-third less water for irrigation than irrigated pastures.

Scenario 2

Mitigating climate change: reducing nitrogen and methane emissions

Two main levers were tested to reduce emissions: a decrease of herd numbers by 5, 10 and 15% (dairy and beef) and a significant introduction of alternative feed in the animal diet of about 10, 20 and 30%. The amount of methane and nitrogen emitted for all scenarios were computed.

Results, displayed in the table below, highlight the combinations that meet the government goals for 2030 (-10% of 2017 emission, i.e., 21.06k Gg CO2eq) and 2050 (-24 to 47% of 2017 emission, i.e., 17.8k to 12.4k Gg CO2eq respectively) in terms of methane emissions. It also displays the nitrogen emission reduction for each combination. A herd reduction of about 10 or 15% combined with an increase of 30% of alternative diet (brassica and grains) in the animal feed allow to reach the objective for methane emissions in 2050. This combination also allows reductions of 21% to more than 23% emissions from nitrogen. A herd reduction of about 0 to 5% and an increase of alternative diet at about 20 to 30% allows to reach the 2030 objective for methane emissions. This combination reduces emissions from nitrogen by 15.2 to 18%.

Methane emissions targets are: -10% of 2017 levels by 2030 (=21.06 Gg CO2eq) and -24% to -47% of 2017 level by 2050 (=17.8k to 12.4k Gg CO2eq respectively). In red, unmet goal, in orange, 2030 met goal, in green, 2050 goal met.

From the environmental side, introducing this alternative feed production in a dairy system could have a clear positive impact, as grain production is almost 8 times less CO₂-e biogenic emissions and request one-third less water for irrigation than dairy pasture.

Scenario 3

Alternative proteins: developing a pea and fava bean protein market in NZ

The total protein produced in NZ in 2019 was 97 g/capita/day (FAOSTAT, see figure below). Out of the 97 g/capita/day, 56g came from animal products and 41g from vegetal products, i.e. 25g from crops, 10g from pulses, oils, roots, nuts and others 6g from fruits and vegetables. Proteins from cereals mainly comes from wheat (69%).

Currently, peas only supply about 1% of the proteins from cereal. Protein from peas in the NZ food supply play a minor role. Scenarios of combinations of land areas, yields, and prices for growing peas to supply up to 10% of the protein needs in NZ have been simulated below.

Baseline = 2021 situation. Note: the scenario parameters assumptions are based on a feasibility report and discussion with the stakeholder. The scenarios assume an extraction facility capable of processing 15,000 tonnes of peas and that the cost for that facility is approximately NZD50 million to establish.

Results show that best combinations allow up to 7 extraction facilities by 2050. High environmental gains are expected:

peas and beans required half the amount of irrigation water,
and 5 times less nitrogen to grow than other mainstream crops,
3 times less than maximum authorized for pastures.

Mapping scenarios

Agricultural area represents 53% of the total NZ land area.

The Dairy sector represents 11% of the agricultural land, which is similar to the forestry sector. The meat and wool sector (sheep, beef, deer production) represents 75% of the agricultural land. Horticulture and arable sectors cover 1% each of the agricultural land.

Data sources: LUCAS NZ Land Use Map 1990 2008 2012 2016 v006, Ministry for the Environment; Land Use Capability, Manaaki Whenua Landcare Research; AgriBase, Asure Quality Kaitiaki Kai.

Of the 10.9 million hectare of agricultural area, 125,000 ha are dedicated to arable crops. Almost 87% of the arable crops are irrigated.

Extending the arable crop production means competing with other sectors on irrigated land:

Dairy sector represents 2.2 million hectares and 47% of the irrigated lands.
Sheep and beef sector represents 2.9 million hectares and 24% of the irrigated lands.

The majority of the irrigated land are located in the Canterbury plain (Ministry for the Environment 2020).

Many knowledge gaps (i.e. precise crop maps, crop rotation maps, cash crop maps) need to be addressed before precise mapping of future scenarios of the arable sector can be produced at a national or regional scale. There is currently limited spatial information about the arable sector due to difficulties in knowing when and where specific crops are being planted.

References

Scientific publications

Vannier, C.; Cochrane, T.A.; Zawar-Reza, P.; Bellamy, L. Development of a Systems Model for Assessing Pathways to Resilient, Sustainable, and Profitable Agriculture in New Zealand. Land 2022, 11, 2334. https://doi.org/10.3390/land11122334

Vannier C., Cochrane T.A., Zawar Reza P., Bellamy L.: “An Analysis of Agricultural Systems Modelling Approaches and Examples to Support Future Policy Development under Disruptive Changes in New Zealand”. Applied Sciences, 12, 2746. https://doi.org/10.3390/app12052746