What has been happening over Winter?

Things have been a little quiet over the last few months. We’ve had our usual regular monitoring tasks, tracking cover crop development with the Canopeo app and soil nitrate levels with the Nitrate Quick Test protocol, Nitrachek device and our conversions to kg/ha. Now we are focusing on getting ready for our summer crop – food quality maize with Nicolle Maize.

We fully discuss the winter cover crop in an earlier post, but in essence, triticale and vetch took off more strongly than annual ryegrass but were overtaken in mid-July after aerating through fill cover and as the triticale was affected by rust. Generally, we are happy with the covers but think growth may be a little less than previous winters. The vetch this year was a standout success after a few years of disappointment.

The free nitrate in the soil has been very low all winter. The chart below tracks the nitrate in the top 30 cm of soil since cover crop establishment. Note this is twice the standard sampling depth.

After being the lowest treatment from mid-April to mid-June, the Regenerative triticale and vetch plots showed a jump and have remained higher (although still very low) than the Conventional and Hybrid ryegrass plots. Is there a link with the canopy cover levels? If the vetch starting to release free nitrate from the nodules?

No fertiliser was added at planting, so the increase in April is assumed to be the result of mineralisation after the butternut crop was harvested and the plots disced and planted. As the cover crops established, they appear to have taken up nitrate although significant rain from 18-21 April may have had some influence.

Soil moisture measured by Hydrosense or oven drying shows no differences between any of the treatments.

Outreach

We had a few opportunities to talk about the Carbon Positive trial over winter. Notable events were taking part in Lincoln University’s State of the Land Event “Regenerative Agriculture in NZ Landscapes: From Practice to Evidence” at which Dan presented the mid-project soil carbon results and use of AI to develop a model to explain changes in and within the various carbon pools. Notably, the emerging science around photosynthates as a key driver of soil carbon suggests the significant fallow and low ground cover typical of an intensive vegetable growing programme is a major block to nett carbon sequestration.

What can we do about that? We think strip-spraying and strip-tillage is one approach. Not only does it retain actively growing (photosynthesising) plants as long as possible, strip-till also minimises tillage – a major cause of carbon burn-off. Several LandWISE Conference presentations addressed this, and the videos have been uploaded to the website.

Another technique would be getting a cover crop growing within the main crop, so that after harvest, it is already growing an “catching some rays”. This however might be a little trickier. Numerous attempts have been made by numerous groups in numerous places and results have been varied. But our Operations Advisory Group is keen that we have a goo. So, we are looking at establishing some legumes in the maize this summer, but leaving sowing until as late as possible to minimise the risk and scale of competition with the money earning maize.

Dan was also asked to present to the annual ICD Group conference. He introduced LandWISE and our history from our roots in wind erosion minimisation, through strip-till, autosteer, precision ag and various nitrate minimisation projects. It was a good opportunity to reflect on 25 or so years on LandWISE activity. While immensely varied, the focus throughout has been on sustainable production through technology and system choice. We have a large legacy of work in soil health, optimal nutrient management and making the best possible use of scare water resources. If you haven’t already, have a look at the various tools and calculators and the online learning courses on our website.

By the time our summer crop butternuts were removed from the Carbon Positive plots, the vines had dried to rope. We disced and direct drilled cover crop seed but couldn’t run an aerator through without massive tangling.

On 26 March, annual ryegrass was sown in both the Conventional and Hybrid plots, and a Triticale/Vetch mix in the Regenerative plots. With very dry, rubbly soil, we irrigated after sowing to help germination.

Because we’ve been disappointed by vetch in recent crops, Olivia ran a germination trial, placing 100 seeds in a tray of plot soil and leaving it outside. This showed 88% germination under field conditions, which we were happy about.

Triticale was first to emerge in drilled plots, with significant numbers by 1 April. Ryegrass and vetch were slower, but well underway by 7 April.

Triticale and Vetch

Annual Ryegrass

By early May, the triticale was well established with roots down at least 20 cm. The vetch roots were also reaching down and had good nodulation.

The ground cover under each cover crop is shown in the chart below. After a lag at initial germination, the ryegrass plots grew at the same rate as the triticale and vetch but did not catch up. The drop at the beginning of June followed an attempt to aerate the soil through a full cover crop once the butternut vine had sufficiently rotted. However, there was some crop damage and the average cover dropped. The regenerative triticale and vetch plots did not return to the previous full ground cover. While the triticale was recovering, around mid-July a leaf rust began spreading through the plots. Even as growth in the Conventional and Hybrid ryegrass plots continued lifting in August, the triticale weakened.

Examples of canopy images taken on 17 August show the ground is well covered, although there are more gaps in the Regenerative image and the presence of rust is apparent.

Conventional Annual Ryegrass

Hybrid Annual Ryegrass

Regenerative Triticale & Vetch

In mid-August we planned to start ground preparation by broadcast spraying the Conventional plots with glyphosate and Torus, and strip-spray the Hybrid and Regenerative plots with glufosinate and Torus. We took above-ground biomass samples on 8 August taking two 0.25 m² subsamples in each of four sub-plots per plot. The charts below show there is no difference in dry matter percentage between treatments. Despite the lower ground cover in the Regenerative plots as assessed by Canopeo, there is a significant difference in above-ground dry biomass compared to the other two which are the same.

Weather has impacted our plans to spray out the cover crops. Our next summer crop will be food quality maize, and the planting date is flexible so we can delay somewhat. But we do want to get next year’s cover crops in while the autumn is still warm, so we don’t want to wait too long.

We plan a public field walk at the MicroFarm on Carbon Positive Field Walk at 1:00 pm on Wednesday 16 September.

Dr. Charlie White is a faculty member at Penn State University, specializing in soil nutrient behavior and management.

He has taught various courses, including Soil Nutrient Behavior and Management, Internship, Independent Studies, Thesis Research, and Supervised Experience in College Teaching.

His research focuses on sustainable agricultural systems, biogeochemical cycles, and nutrient management to promote productive and efficient nutrient use in cropping systems.

In this presentation, Charlie will share some of the key insights into managing cover crops for nutrient management and soil health that he has learned through twenty years of research, much of it conducted in partnership with farmers in the temperate, humid climate of the Mid-Atlantic USA.

These lessons include the importance of measuring and managing cover crop and soil organic matter carbon, nitrogen, and C:N ratios to balance nitrogen retention and supply; that a little bit of grass in a cover crop mixture goes a long way to reducing N leaching; and that a cover crop mixture with balanced species proportions will be the most multifunctional, but achieving evenness in the biomass is easier said than done.

Finally, Charlie will return to his roots in reflecting on the importance of mycorrhizal fungi to the phosphorus nutrition of crops, and why P stratification in no-till system may not be as much of a problem as we think because of these symbiotic organisms.

Session Synopsis

Growing multiple vegetable crops across a farming operation the size of Harvest Moon requires constant decision-making, careful timing and a deep understanding of what crops need at every stage of growth. In this session, Josh will walk through how Harvest Moon manages nutrient applications across more than a dozen crops using a combination of field experience, soil and sap testing, and modern data tools.

He will explain how the team schedules and calculates nutrient inputs throughout the season, how they identify inefficiencies in the system, and how these insights feed into broader Integrated Pest Management strategies. By continually measuring and refining what happens in the field, Harvest Moon is able to reduce risk, improve crop health and optimise yield.

The session offers practical, real-world insights for growers looking to sharpen their nutrient strategies, improve efficiency and get more value from the data already available in their farming systems.

Making sense of carbon movements. History of strip-till.

Co-founder and manager of LandWISE since 1999, Dan’s career is diverse, with a constant theme of sustainable use of land and water resources. His post-graduate studies included an MScTech in innovation Management and adoption in the primary sector, and a PhD investigating the potential of ultra-low energy electric weeding.  He brings experience across fresh and process vegetable growing, kiwifruit and arable production, to complement expertise in extension, soil health and efficient water management.

Dan is the architect of the Carbon Positive project. At LandWISE 2026, he will present data from soil carbon monitoring in the Carbon Positive project and introduce the use of AI to help understand changes in soil carbon pools.  Powerful, yes. But trustworthy?

Later, he will dive back in history to recall pioneering research into the adoption of strip tillage to minimise soil erosion and soil health impacts. That work saw the formation of LandWISE, ultimately as a stand-alone organisation promoting sustainable production through leadership, support and research. Dan remains a strong advocate for strip-till done right, having seen first-hand its contribution to better soil health, minimised fuel requirements, and financial advantages.

In this presentation, Uttam presents research tracking the impacts of Cyclone Gabrielle over time, industries, ecosystems and communities. When the flood waters drain away, things are far from over.

2. Do all nitrogen amendments have the same footprint?

In this presentation, Uttam will discuss the environmental footprints of alternative nitrogen amendments, providing information for those focused on reducing their carbon emissions to meet market expectations.

Uttam Floray works at the intersection of climate science, primary industry, and real-world delivery. With a background in the wine sector across New Zealand, Australia, and the United States, he has led production, compliance, and commercial operations while embedding environmental performance into the core of the business. At Toitū Envirocare, he leads work supporting organisations across the primary industry, manufacturing, and transport sectors to measure, manage, and reduce emissions. Uttam’s focus is on guiding clients through the right climate impact programmes — ensuring they add real value, align with credible standards, and translate into practical, implementable action. He works closely with organisations navigating complex requirements, helping them move beyond compliance toward meaningful, science-aligned outcomes.

Uttam has a range of qualifications including a BSc in Biotechnology and a Bachelor of Viticulture and Wine Science from EIT. Uttam is now involved in a lead role with Electrify Hawke’s Bay, a regional group promoting adoption of low carbon alternative energy sources including solar.

Katherine Martin is a consultant at Perrin Ag, working across agronomy, farm systems, and environmental planning to support growers in improving productivity and strengthening environmental outcomes. Her work spans vegetable and pastoral systems, with a strong focus on soil health and regenerative practices at the paddock scale, alongside translating research into practical, farm‑ready insights for growers.

Intensive vegetable systems often leave soil bare between crops leading to nitrogen leaching and soil erosion. Crop stacking offers an innovative approach keeping living ground cover in place for the months that would otherwise be fallow.

After harvest, a “sentinel” cover crop is established, once the cover crop is established, narrow planting strips are selectively sprayed to plant the commercial crop into. The cover crop is left in place during early commercial crop establishment; the cover crop is desiccated two to three weeks later to avoid it outcompeting the commercial crop.

This presentation shares findings from a three‑year programme (2023–2025) testing crop stacking in a commercial broccolini system in Pukekohe. Across multiple seasons, crop stacking consistently reduced the risk of nitrogen loss, by up to 31%, and resulted in lower levels of mineral nitrogen moving deep into the soil profile. Trials also showed strong early crop establishment, increased yields, and noticeably less soil erosion.  Together, the results show that crop stacking can deliver real environmental gains with the potential to increase productivity.

Minimising cultivation impacts in broadacre cropping

Simon White is a farmer and entrepreneur based in Otane, Hawke’s Bay. He and his wife, Lou, have built a diverse operation with soil health at its core. They have a mix of arable cropping and sheep and beef finishing across 1100 hectares which has been in their family for three generations. Simon and Lou won the regional supreme title at the 2025 East Coast Ballance Farm Environment Awards, which recognised their focus on sustainability and business success built on diversification and innovation.

Simon is a long-time user of direct drilling and strip tilling on his farm. He sees major benefits in time saving, fuel economy and soil health. He will describe his use of these techniques in his arable, seed production and process vegetable systems.

LandWISE Conference 2026

Havelock North Function Centre
27 – 28 May 2026

Our “Soil Health for Profit” theme in 2026 is, in some ways, a return to the past. LandWISE arose out of work to combat soil erosion through use of minimum tillage and we’re returning to strip-till in 2026. A lot has been learned in the intervening years! Along with that, we’ll look at what can be done to measure and manage crop nutrition and soil health to ensure sustainability and long-term profitability.  

We have international speakers from Pennsylvania and Tasmania complementing national and local growers and experts. They will share how they set out to build profitable enterprises with a focus on soil health and an eye to wider sustainability ambitions. We’ve asked them to offer ideas of things to take home and apply or try – to feed the appetites of keen delegates.

We have talks from people applying regenerative principles in cropping, pastures and orcharding, talks on strip-till and crop-stacking, soil amendments and cover cropping, and managing and minimising the cost of nutrients. As always, expect representation of agritech covering a wide range of technologies.

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