Sustainable Land Management and Climate Change research reports

The objectives were to create an assessment methodology to identify maladaptation in adaptation strategies and develop a decision-making, education and communication tool for diverse communities to understand and evaluate how effective specific adaptation projects will be. This initial attempt at tackling a complex problem included three case studies and unearthed some significant gaps in the current state of knowledge and practice.

Keywords: climate adaptation; maladaptation; climate resilience; community adaptation;

This research set out to determine whether a theoretical 27% reduction in N-loss from a typical dairy farm on stoney soils in Canterbury could be achieved by radically changing the irrigation management strategy. Due to the highly variable physical structure of stoney soils, tightly managing the level of leachable N to closely match plant needs, while also considering predicted rainfall, is a more important N-leaching strategy than is fine tuning irrigation application efficiency.

This work explored agri-voltaics (combined solar electricity generation and agriculture) as a means of renewable energy production and improved pasture productivity, animal welfare and resilience in a changing climate. The study used pasture modelling tools combined with on-farm measurements to assess the impact of solar arrays on pasture and identify those regions for which agri-voltaics would be most beneficial. Understanding how large-scale solar electricity generation on pasture can deliver improved productivity and livestock welfare in a changing climate.

Research was undertaken at two large field experiments to evaluate the performance of one of two pasture-based wintering system options over three winters – bale grazing in northern Southland and pasture and baleage in South Otago. A general recommendation from the project is that pasture-based wintering of cows can be successfully undertaken, providing some important design and management criteria are incorporated into the chosen system.

The project observed six Otago and Southland sheep, beef and deer farmers use of multi-species, multi-graze cropping options over three winters to help improve animal feeding outcomes while reducing potential environmental damage. Crop yields and nutrient concentration data were collected in July, along with the farmers’ self-collected data and observations. Case studies highlight the range of uses and experiences which occurred at the individual farm level, as well as providing some collective experiences.

Comprehensive monitoring of the flow and water quality at inflows and outflows was undertaken from 2021-2024 at three pre-existing and three new Constructed Wetlands (CWs) in contrasting landscape settings. Sites exhibited considerable variation in inflows and loads of nutrients and sediment during and between years. These data were collected in fine time scales and they add significantly to the performance information supporting the use of CW’s in New Zealand. The sites continue as a ‘demonstration network’, showing how constructed wetlands can improve attenuation of diffuse runoff in pastoral landscapes.

The aim of this project was to provide a summary on the use of salt supplementation of dairy cows to mitigate N leaching and nitrous oxide emissions and to recommend how salt supplementation could be incorporated into OverseerFM. The project confirmed that salt supplementation is most effective in reducing N leaching when used during autumn. It recommends that evaluating changes to the default N loading rate in OverseerFM be the next step.

This SLMACC project followed on from a 25-year study of farm system impacts following land use and management change in the 260-hectare Mangaotama catchment farm (within the former Whatawhata Research Centre). The project has supported an improved understanding of the costs and benefits associated with land use and management change in pastoral hill country, occurring over time scales of multiple decades.

The objective was to compare leaching losses of N and P from diverse pastures, consisting of 5-8 species, with losses from traditional ryegrass-white clover at two sites, near Lincoln, Canterbury and Tihoi, Waikato. Large-scale lysimeters were employed to directly measure leaching for a range of management intensities and across different soil types over four years. The results did not show a consistent difference in leaching between the two pasture types. However, pasture establishment was variable across the sites, with high losses recorded during drainage events that occurred when pasture establishment was incomplete. These results suggest timing of management activities, such as cultivation and irrigation, is likely more important than pasture species composition for reducing leaching losses.

This project sought to provide new information on how catch crops could be established earlier, better managed and shown to reduce the risk of nitrogen leaching and runoff and provide production benefits. The research examined crop choice; sowing method, timing and rate; lysimeter measurements; modelling and farmer uptake of the results. An engaging and collaborative approach was taken throughout the project, from trial establishment on working farms to linking with other researchers and Overseer Ltd as findings emerged.

This project explored management options to maximise the ability of radiata pine to transfer nitrogen from nutrient-rich soils into tree biomass. The project collected data from 12 existing afforestation sites and 3 newly installed pastoral afforestation trials, enabling projections of nutrient movement and storage over the life of a rotation. These predictions demonstrated a substantial opportunity exists to rapidly reduce soil nitrogen loads to manageable levels, but the 3 new afforestation trials need to run another 4 to 5 years to provide sufficient evidence to enable confidence in wider adoption. The trial sites, on Pamu Farms properties, are a unique resource, and could be utilised for silvopastoral systems research on biostimulants, residue management and biofuel generation alongside pastoral farming.

The research was divided into two main objectives which comprised firstly of generating herd testing data (using urine sensor technology) on four case-study dairy farms (located in Waikato and South Auckland, New Zealand) over the first two years of the project (Objective 1). The second phase of the project (Objective 2) utilised data generated in Objective 1 for scenario-based modelling using OVERSEER® model (OverseerSci, version 6.5.1) and subsequent research on how this information could be integrated into the model to mitigate farm N leaching loss with future research and challenges identified.

In this co-designed programme the impacts of predicted climate change and water limitation were considered for the communities in the Ngāti Pāhauwera rohe so that they may understand and identify aspirations and options for future land use for the multiple-owned, small, less well developed and discrete land blocks under those challenges.

This work was part of the critical understanding needed for working with whānau to look at the future use of their whenua, particularly enterprise options suitable for their land blocks in a changing climate that meet their economic, cultural and environmental objectives.

Climate change will influence future production of agricultural commodities (where “agriculture” includes pastoral farming, cropping, horticulture and forestry) in Aotearoa New Zealand and elsewhere, affecting global supply and demand, and altering trade patterns. This project used a large dimensional global trade, climate and economic model to forecast the impacts of climate change on supply and demand for NZ agricultural products, hence associated impacts on trade patterns and pest/disease redistributions, both at the national and regional level. This will help identify future market access opportunities and biosecurity policy needs.

These case studies report on the regional development potential for a durable hardwood industry in Marlborough that could produce over $90 million in GDP based on 5,000 ha of sustainably managed eucalypt forests established between 2025 and 2055. The second report covers a more detailed investigation and evaluation of individual property case studies: the potential economic and environmental implications of growing durable eucalypts to supply a new industry on four individual Marlborough farm and forestry properties.

These case studies report on the regional development potential for a durable hardwood industry in Marlborough that could produce over $90 million in GDP based on 5,000 ha of sustainably managed eucalypt forests established between 2025 and 2055. The second report covers a more detailed investigation and evaluation of individual property case studies: the potential economic and environmental implications of growing durable eucalypts to supply a new industry on four individual Marlborough farm and forestry properties.