Our hand harvest samples were taken from 3 m × 2 m areas within each of the four subplots of each plot; 16 per treatment, 48 in all. All butternuts within the sample area were cut from the plant, counted, and weighed. A subsample was collected for Brix, dry matter, nitrogen, and carbon analysis. The plant residue was also weighed, and a subsample was collected for dry matter, nitrogen, and carbon analysis.

On the 10th of March, the butternuts were cut for fresh market and placed into windrows ready to be collected into bins.

The main differences between treatments were cultivation method, biological and foliar applications, and fertiliser inputs. The Hybrid and Regenerative treatments were strip-tilled, while the Conventional treatment was fully cultivated. The Regenerative treatment received the most biological and foliar applications, the Hybrid treatment received some, and the Conventional treatment received none. The Regenerative treatment also received significantly less nitrogen (18 kg N/ha) compared with the Conventional treatment (77 kg N/ha) and the Hybrid treatment (67 kg N/ha).

The Conventional treatment yielded 52.74 T/ha, the Hybrid treatment yielded 52.00 T/ha, and the regenerative treatment yielded 49.44 T/ha. While these yields look slightly different, there is no significant difference in yield between the treatments (P>0.05). Our highest and lowest yielding sub-plots were both in the regenerative treatment!

We will discuss these findings at the LandWISE Conference: Soil Health for Profit in May.

Conference information and registration is available on our website.

We were delighted to have Carys Luke join us as our Summer Intern in 2025-2026. Carys’ key project was measuring soil infiltration rates using disc permeameters. These devices work under tension, so water has to be pulled into the soil by capillary forces. By controlling the amount of tension, we can set the soil pore sizes that are dragging water in, and so we can get an estimate of the soil’s pore size distribution.

There’s a fair bit of maths and interpretation so to help, we made an online calculator and published interpretation guidance. We would like to hear your feedback if you go looking. The equipment is not commonly available and is mostly a research tool rather than for everyday farmer use. If you think you would benefit from measurements, contact us and we can discuss options.

This report evaluates soil water infiltration across conventional, hybrid, and regenerative
management treatments in a randomised block design (12 plots) within the LandWISE
Carbon Positive experiment. Infiltration rates were measured using disc permeameters
at the soil surface and at 10 cm depth under supply tensions of −15, −6, and −3 cm.
Applying water at these tensions enabled hydraulic conductivity to be assessed across
three pore-size domains (<0.2 mm, <0.5 mm, and <1.0 mm), providing insight into pore
size distribution and how it varies between treatments.

Infiltration generally increased as water tension became less negative; however, contrary to published literature, infiltration often plateaued or declined between −15 cm and −6 cm tensions. The readings at lower tension (-3cm head vs -15cm head) should icrease because more mores are taking water. These results indicate that our measurements at −15 cm tension frequently did not reach true steady state. You can see this in Figure 6.

A key recommendation is to ensure sufficient time is allowed, and that more measurements, possibly at greater intervals, are made than were done for this study. In a soil such as ours, it can take a very long time (hours) to get to the steady state, and it may not be apparent until data gets analysed. Ooops.

Carys’ full report is available in our file stack.

Do you have a classifiable dam? Make sure you have notified the council and submitted your Dam Safety Assurance Plan to avoid an infringement notice.

Unsure if your dam counts? Check out MBIE’s new tool on Classification screening tools for Dams and Canals

New regulations to improve the resilience and maintenance of Aotearoa New Zealand’s dams have now been in force for a year.  This means owners of ‘classifiable’ dams are now subject to additional responsibilities to protect people, property and the environment from the potential impacts of dam failures.

If you own a dam that is 4 or more metres in height and stores 20,000 or more cubic metres volume of water or other fluid, you should already have submitted a dam classification certificate to the appropriate regional authority. If you haven’t done so yet, it’s important to begin the classification process as soon as possible. This includes engaging a recognised engineer to certify your dam. You should also notify your regional authority that you’ve started the process.

Owners of classifiable dams with a high potential impact classification (PIC) must submit a Dam Safety Assurance Plan (DSAP) within one year of the council approving the classification. These deadlines are quickly approaching and dam owners will need to engage a recognised engineer to audit and certify the DSAP. If dam owners do not comply with the regulations, Regional Authorities may issue infringement notices.

Resources to help you

The Ministry of Business, Innovation and Employment (MBIE) has published a tool to assist dam owners determine whether their classifiable dam is likely to be a low potential impact dam, or whether further judgement may be required to determine the classification.

Classification screening tools for Dams and Canals

You can read more about the definitions, regulations, and find resources to support you, on MBIE’s Building Performance website: www.building.govt.nz/managing-buildings/dam-safety/

Included in these resources is the Measuring and calculating the height and volume of agricultural dams resource. This is designed to help horticultural or agricultural dam owners calculate the volume of their dam and understand if they are impacted by the Regulations.

MBIE has also published another resource, the Potential Impact Classification checklist, which is a checklist to support dam owners to identify and collate information for a PIC assessment.

The Guide to complying with the Dam Safety Regulations has been updated to clarify some points.

The LandWISE Conference, Getting to Carbon Positive, attracted more than 80 people who heard speakers on a wide range of topics related to ongoing sustainability.

Day 1 discussed ways to assess our emissions levels, how we can reduce our environmental impact through diverse farming techniques including regenerative practices and soil health, and new research around pest management.

Pii-Tuulia Nikula opened with an introduction to emissions accounting, which was followed by Uttam Floray outlining how Toitu certifies emissions. Ron McFetridge from WaterForce said he was asked by key clients about WaterForce’s emissions, which set them on a journey to reduce their emissions and environmental impact. Olivia’s take:

“I enjoyed listening to Ron discuss how WaterForce has been installing solar panels on their offices, putting in electric vehicle chargers, and deploying electric and hybrid vehicles for their staff. Given that they travel 4.5 million kilometres annually as a company, WaterForce saw electrification as an effective way to reduce emissions and environmental impact. By doing this, they are setting a precedent for other companies.”

Dan Bloomer presented results from the Carbon Positive trial including the 2024-2025 cropping programme and a Carbon balance for each of the treatments, which showed nitrogen fertilisers and diesel were the largest CO₂^-e contributors. The introduction of livestock added significantly to overall emissions, even if on farm for a relatively short time. Matt Norris presented results from regenerative cropping trials, including use of composts, at LeaderBrand in Gisborne, Angus McKenzie described how Wairuna Farm is applying the principles in Canterbury, the various things he had been trialing on his farm, and how they created a wetland to treat drainage water. Sam McNally addressed ways to increase soil carbon and explained fundamental changes in our understanding of soil carbon sequestration and carbon pathways. Photosynthesis feeds the whole system!    

Three speakers discussed beneficial non-crop plants. Dan talked about the lessons from growing multispecies cover crop mixes in the Carbon Positive trial. Charles Merfield provided information about cover crops for regenerative cropping and the need to ask what functions you wanted cover crops to perform. Jeff Smith presented lessons from biostrip and insectaries research through the A Lighter Touch project.

Day 1 was wrapped up with Asha Chhagan talking about new technologies to assist pest and disease management, and Bethan Shaw reporting on work done looking at earwigs recolonising orchard sites that had been devastated by Cyclone Gabrielle. Daniel Sutton and Chris Lambert reporting on trials with a camera equipped AI enabled pest trap.

Olivia’s take:

“The conference was a good opportunity for me to do my first conference presentation! I talked about the Slakes app and things we have learned from using it to assess soil aggregate strength, and I spoke about the Nitrachek device project that I have been running as a part of my Te Ahikawariki/VICE internship.”

Many thanks to all our sponsors, speakers and delegates!

The cover crops were direct-drilled by Mike Kettle contractors on the 7th of April. There was good moisture, but hot dry winds rapidly dried the soil out. Annual ryegrass was drilled in all treatments. The Hybrid plots also had two clovers added, and the Regenerative plots had two clovers and vetch.

After planting, the plots were aerated and rolled by Patrick Nicolle, and we aim to stay off them until October, prior to planting butternuts for Heinz-Wattie’s.

After 28 mm of rain and a few days of warm temperatures, the cover crops began emerging on the 18th of April. Both the annual ryegrass and vetch were well out after a few days, although the clover is slower. We drilled slug bait with the seed, and will apply a surface dose by quadbike after the rain and now emergence is underway. The amount of surface residue is apparent in the images below, and we suffered damage in such conditions with previous crops.

We expect the cover crops will be at a good stage for viewing at the LandWISE 2025 Conference Horizons Regional Council Field Session on 22 May.

As part of my Te Ahikawariki/Vegetable Industry Centre of Excellence (VICE) internship I have been helping Dan run workshops in Pukekohe, Palmerston North/Levin and Gisborne. As apart of these workshops we have been demonstrating how to use a Nitrachek device.

The Nitrachek device produces a nitrate parts per million (ppm) result based on the colour of a nitrate test strip. The Nitrachek is designed to use the MQuant Nitrate test strips to produce an accurate reading.

There is an international shortage of MQuant nitrate test strips at present, so we wanted to know if Quantofix test strips can be used instead.

The Quantofix test strips were compared to the MQuant test strips in the Nitrachek (set to lot 5) using nitrate solutions with different concentrations: 500, 250, 125, 62.5, 31.25, 15.63, and 7.81 ppm.

The Quantofix Nitrachek readings were much lower than the MQuant Nitrachek readings.

Quantofix vs MQuant Nitrachek readings on lot 5.

Conclusion

Based on the trend line equation, it was determined the Quantofix test strips can be used in the Nitrachek device on lot 5 and can be corrected by multiplying the Nitrachek ppm reading by 2.2. This will produce a similar result to a Nitrachek reading on lot 5 with a MQuant nitrate test strip.

Download file

– Olivia

To adopt a new Constitution for LandWISE Incorporated

There will be an on-line Special General Meeting held at 4:30 pm on Thursday 1st May 2025

Full Members (currently registered financial members) have been sent an on-line meeting invitation and links to more information and an on-line ballot form directly.

Background

The Incorporated Societies Act 2022 (the 2022 Act) came into effect on 5 October 2023. To reregister, our society must provide a constitution that is compliant with the 2022 Act, which sets out what we must include in our constitution.

Details of changes to legislation are viewable at
https://is-register.companiesoffice.govt.nz/law-changes-for-societies/key-changes/

The New Zealand Companies Office is responsible for Incorporated Societies. It provides an on-line Constitution Builder that sets our mandatory, strongly recommended and optional components for a constitution to meet the requirements of the new Act.

The LandWISE Board has met frequently to review our old constitution and draft a replacement that meets the new requirements. The Board considers the attached draft Constitution suitably describes our Purposes and Rules for operation. It asks that members approve this draft as the LandWISE Constitution 2025. With membership approval, the Constitution will be submitted to Incorporated Societies and to Charities for their acceptance.

In June this year, I was chosen for one of two teams attending the 2024 International Food and Agribusiness Management Association (IFAMA) Case Study Competition and Conference in Almeria, Spain. The theme of the conference was Food Security Through Innovation & Sustainability. We were then invited to attend a weeklong food and agri-innovation tour to Bologna, Cologne and then through the Netherlands.

I am lucky to have been in a team with four clever individuals from across the New Zealand Agri-Food sector. Our team included Dan from Silver Fern Farms in Dunedin, Fatima from ANZ in Auckland, Braydon from Perrin Ag in Rotorua, and Katie from Auckland University. We brought a diverse range of skills to our case study analysis, as well as a diverse range of opinions and perspectives on agriculture.

We were incredibly excited to learn that we won first place in our division, with the other New Zealand team coming in second place. Not bad for a little country at the bottom of the world!

While travelling together after the conference we were able to explore food provenance and food culture in Bologna, agricultural research and development in Cologne, and agricultural and horticultural innovation in the Netherlands. We will all be spending the next few months digesting what we have seen, discussed and learnt, and how our experience links to food production back here in New Zealand.

Many thanks to LandWISE (Dan & Phillipa) for allowing me the time away to learn, grow and explore the agri-food sector at a global level.

Applications are open!

Applications are open for the 2024 STAMP intake so if you have talented young people in your business (under 27 at the time of application), encourage them to apply! Click here for more information. Applications close 31st Aug 2024.

The last few months has seen us researching and confirming management strategies for our spring tomato crops. A major component is crop protection planning for conventional, regenerative, and hybrid treatments. In a conventional tomato growing system, the 135 day crop typically receives about 15 spray applications, all with several active ingredients. Regenerative principles seek to reduce agrichemical additions. We have been working with the Watties team and industry advisors to prepare a minimum crop protection programme that should provide an acceptable level of risk to the crop, to people, and to the environment and the soil biological community.  

Measuring any potential agrichemical impact and comparing systems is a complex task. There are different types of harm to consider i.e., harm to humans, harm to insects, harm to birds, harm to soil life, etc. How do we describe and rank “harsh” or “soft chemistries? Is our proposed regenerative cropping programme “better” than the conventional one?

McCain’s Agronomist, Ben Prebble proposed the Environmental Impact Quotient (EIQ) model to rate and compare programmes. The EIQ formula was developed at Cornell University by Kovach et al., (1992) to inform growers and advisors wanting to make more environmentally friendly crop protection decisions. The model considers a range of effects (Figure 1), which are categorised into three components: 1) Consumer EIQ, 2) Farm Worker EIQ, and 3) Ecological EIQ. The Environmental Impact Quotient EIQ is a weighted numerical score that allows different active ingredient choices to be compared.

An online tool for calculating EIQ is available through Cornell University (Grant, 2020). This tool uses the base product EIQ value to calculate a Field Use EIQ based on the applied rate of each product. Figure 2 provides an example of the calculator for glufosinate-ammonium (Buster).

Note that regardless of selected application area units, the Field Use EIQ is given in acres (Figure 3), so answers need to be multiplied by 2.47 to give Field Use EIQ per hectare. It is the Field EIQ values that can be used to compare options.

We have used the EIQ tool to calculate a ‘Total Field Use EIQ per hectare’ value for our tomato treatments. The proposed Field Use EIQ for the regenerative treatment is about half that of the conventional treatment. Of course, our production plans are subject to change based on seasonal events! Major contributors to a higher EIQ in the conventional treatment are the use of the pre-emergent herbicide Prosulfocarb, more frequent use of the fungicide mancozeb, and the use of copper hydroxide. We planned a regenerative crop protection programme for growing 100 T/ha, but which has a lower impact on the receiving environment, those handling the chemicals on farm, and those consuming the tomatoes.

We used the University of Hertfordshire Pesticide Properties Data Base (PPDB) for additional information on each active ingredient (University of Hertfordshire, 2023). The database provides information on soil degradation, soil mobility and adsorption, ecotoxicity (including harm to earthworms and honeybees), and risk to human health. A traffic light system is used to indicate risk to environment, ecotoxicity and human health Figure 4.

We are pleased we have a more objective way to assess each of our programmes and their components. The EIQ system is the result of three decades of research and modelling by many people in many organisations, who also incorporated decades of accumulated knowledge – it is not something we could have come up with overnight!

References

Grant, J. (2020). Field Environmental Impact Quotient (EIQ) Calculator [New York State Integrated Pest Management Program, Cornell Cooperative Extension, Cornell University.]. Calculator for Field Use EIQ (Environmental Impact Quotient).

Kovach, J., Petzoldt, C., Degni, J., & Tette, J. (1992). A method to measure the environmental impact of pesticides. New York’s Food and Life Sciences Bulletin, 139.

University of Hertfordshire. (2023). PPDB: Pesticides Properties Data Base. PPDB: Pesticide Properties DataBase.

The first week was spent in Washington State starting in the Yakima region. We are most grateful to Ines Hanrahan, Director of the Washington Tree Fruit Research Commission for arranging our visits and being our host and guide. We visited fruit packing and dispatch facilities, orchards and research centres, and looked out our bus windows as we covered many miles through orchards, vineyards and crops in a very low-rainfall area. The soils, climate and availability of water from stored snowmelt are very good and have enabled the very large state fruit industry to develop. Many operations are still family owned and operated, albeit at very large scale.

So what are their issues?

Speaking with Brett Valicoff, it would seem they face very similar challenges to New Zealand growers: increasing cost and reducing availability of labour, biosecurity threats with new pests and diseases and a reducing set of active ingredients to control them, climate change and reducing water security, and trying to make a buck with rising costs and reducing returns. It sounded very familiar.

Packhouse and dispatch automation plays an increasing role and places we visited have made significant investment. As well as the expected automated fruit grader systems, there was a move toward more automation in packing lines, including using Robotics Plus technology. We saw robotic pallet stackers at the Valicoff Fruit Company, and fully automated storage and inventory handling at Matson Fruit’s cold storage warehouse in Selah. Later in Bingen, we viewed the automated pear packhouse at the Mt Adams facility, where we saw the use of grader-scanned images of fruit to retrain algorithms for any new quality problems that arise.

A visit to the USDA-ARS Temperate Tree Fruit and Vegetable Research Unit in Wapato focused on entomology. The unit aims to provide growers with effective and sustainable tools for integrated pest and disease management, and consumers with safe and healthy produce. None of our group is keen on meeting a Northern Giant Hornet, a huge pest that quickly destroys honeybee colonies.

Many thanks to

• Rebecca Schmidt Jeffris for her presentation on natural enemy management of earwigs, identifying non-target effects of herbicides on natural enemies, and natural enemy releases with drones.
• Jacqueline Serrano for her talk on lures to better monitor introduction and spread of Northern Giant Hornet (Asian Giant Hornet, or murder hornet) which we certainly do not want. She also works on other hornets that may be relevant to NZ.
• Rob Curtiss for his presentation on the use of sterile insect releases for codling moth control in apples and pears via drones.

On-orchard, we had the opportunity to spend a few hours with Kyle Cobb and the Advanced.Farm crew who were field-testing two of their Robotic Apple Harvesters. Building on their success with robotic strawberry harvesting, the team is moving to the vertical plane for apples grown on a 2D systems, the same as in New Zealand. Refreshingly, they were clear that there is a way yet to go before the technology competes with human pickers.

At the Monson Fruit Company we were given a demonstration of Hectre’s New Zealand fruit scanning technology in action. The system’s camera scans all fruit on the top layer of bins as transport trucks bring it into the packing facility, with image analysis algorithms giving high quality statistics to aid logistics. Hectre has presented at LandWISE conferences, but it was great to see the system working for real in a large US facility. Growers reported trying many of the New Zealand bred apple varieties but had found a number “just don’t seem to do well”. The US Honeycrisp and related varieties fill a large part of their market.

A visit to Craig Harris’ cherry orchard introduced the re-emergence of the virus, Little Cherry Disease, or Western-X, which historically has severely impacted US and Canadian production over decades. Complete tree removal including poisoning to kill infected roots before they graft with neighbours is the current response, resulting in 240,000 trees being removed between 2015 and 2020, with more cases of the disease still being identified. Slow symptom expression makes it likely the disease has spread before it can be detected.

Hops are big business in Washington State and the area around Yakima, which produces about 80% of the world’s hops. With harvest in full swing, we were able to follow the process from the field, through transport, offloading, stripping, cleaning and drying, to baling and finally to examples of the product. New Zealand varieties such as Nectaron feature among the many US ones.

Moving eastward we reached the Washington State University campus at Prosser, which Dan last visited for a week when learning about the CalPoly irrigation system auditing procedures in 2003! This was the basis for the New Zealand Piped Irrigation System Performance Assessment Code of Practice and variants such as IRRIG8 and the simplified bucket test. At Prosser, Gwen Hoheisel talked to us about spray application technologies and current research into precision spraying and a solid-set delivery system for tree fruit, table grapes, and wine. Ex-pat Kiwi Scott Harper, Program Director of the Clean Plant Center Northwest, gave an overview of their activities removing viruses from plants, especially related to tree fruit, hops, grapes. Later, at the Center for Precision & Automated Agricultural Systems, Matt Whiting and Manoj Karkee presented some of their research into automation including robotic apple pruning and harvesting.

Crossing the arid high desert south of Prosser, we reached the irrigated zone fed from the Columbia River and were hosted by Kevin Corliss and Mike Means at the Ste Michelle, Paterson Winery. Once again, the soils and climate, combined by access to plentiful water, have enabled a large industry to develop. The contrast between irrigated and unirrigated is stark. The Ste Michelle vineyards are moving away from wooden posts to relatively simple warratah supported systems, which seem suited to mechanised installation along with their current mechanical planting.

Following down the Columbia River, we dipped into Oregon to visit Chris Adams at the Oregon State University Mid-Columbia Experiment Station. There is good collaboration with the Washington Tree Fruit Research Commission and others with work primarily on pear and cherry production systems, integrated pest management and post-harvest storage.

Many thanks to the Callaghan Innovation team who organised and led the Horticultural Automation Immersion tour: Kev O’Reilly, Andrew Cameron and Simon Yarrow. Thanks to all our Washington State and Oregon hosts for generosity of time and knowledge sharing. And thanks to Kiwi travelling companions for their insights and openness about both our US experiences and their aims and activities in New Zealand.

Reports from California visits and the FIRA Robotics event in Salinas to follow.