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.

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

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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All three treatments were then disced twice. Since the ground was so hard and dry, the first pass with the discs was quite blocky, but after the second pass, there were plenty of fines for a seedbed.

The Conventional and Hybrid treatments were both planted with Moata ryegrass (25 kg/ha). The Regenerative treatment was planted with triticale (80 kg/ha) and vetch (50 kg/ha). Butternut residue made drilling tricky as long “ropes” of dried vine blocked equipment. The hard, dry, rubbly surface in areas such as wheel tracks left seed above the ideal soil mix. Normally we would aerate as the last autumn operation, leaving the soil fractured over winter and spring. We think the butternut residue will make that extremely difficult, so have postponed it. If the soil is still dry enough once residues have rotted, we can aerate in a couple of months.

Thank you to Mike Kettle Contracting for doing our groundwork and planting our cover crops.

Because the soil is so dry, and with no rain on the Hawke’s Bay horizon, we are applying 12 mm of irrigation to ensure good establishment. Once complete, we plan to apply bait as our slug populations are extremely high and past experience showed they have major effects on cover crops, especially the vetch we have planted.

A big thank you to all the Operation Advisory Group members who have attended our weekly field walks and helped make decisions for our cover crops.

Carbon Positive is a partnership between LandWISE, the HB Future Farming Trust, McCain Foods, Heinz-Wattie’s and Process Vegetables NZ.

Our butternut hand harvest of replicated plots was completed on the 9^th and 10^th of March. Four subplots of 6m² were sampled from each plot. All butternuts within the sample area were cut from the plant, counted, and weighed. A butternut 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. Notably, although there are slight differences in the various metrics we assessed, none are significant at a 5% confidence level.

Butternut fruit yield

Yields were very high. We planted assuming 25 – 30 T/ha of butternuts but grew almost double that. The conventional treatment had an average yield of 52.74 T/ha, the Hybrid treatment had 52.00 T/ha, and the Regenerative treatment had 49.44 T/ha.

Butternut residue

The Conventional treatment had an average residue biomass of 20.57 T/ha, the Hybrid treatment had 20.25 T/ha, and the Regenerative treatment had 17.56 T/ha with differences again not significant.

Dry Matter

A subsample of butternut residue was dried to calculate the dry matter percentage. All three treatments had an average dry matter of 16%.

The Conventional treatment had an average dry matter of 8.44 T/ha, the Hybrid treatment 8.37 T/ha, and the Regenerative treatment 7.77 T/ha. While showing slight differences, these are again not significant differences between treatments (P>0.05).

Nitrogen percentage

The nitrogen percentage in the butternut plant residue was determined by Hill Laboratories. The Conventional treatment butternut residue had an average nitrogen percentage of 1.95%, the Hybrid treatment had 1.78%, and the Regenerative treatment had 1.70%.

To calculate the amount of nitrogen in the butternut residue, the dry matter (T/ha) was multiplied by the nitrogen percentage and converted to kg/ha. The Conventional treatment had 163.92 kg N/ha, the Hybrid treatment had 148.63 kg N/ha, and the Regenerative treatment had 131.97 kg N/ha.

Carbon percentage

The percentage of carbon in the butternut residue was determined by Hill Laboratories. The Conventional treatment had an average carbon percentage of 35.25%, the Hybrid treatment had 34.20%, and the Regenerative treatment had 35.50%.

The butternut residue dry matter (T/ha) was multiplied by the carbon percentage to get tonnes of carbon per hectare. The Conventional treatment had 2.95 T C/ha, the Hybrid treatment 2.86 T C/ha, and the Regenerative treatment 2.76 T C/ha.

Brix

To measure Brix levels, a subsample was taken from two butternuts from each sample area. The subsample was grated and squished in a garlic crusher, and the juice was tested with a Refractometer.

The Conventional treatment had an average Brix level of 7.1%, the Hybrid treatment 7.9%, and the Regenerative treatment 7.0%.

If Wattie’s had harvested the butternuts, Brix levels would have been assessed prior to harvest. Heniz-Wattie’s minimum brix level before harvest is 7%, ideally, they would be harvested between 9–10% brix. As the butternuts were harvested by a local grower approximately one month earlier than Heinz-Wattie’s standard harvest timing, the Brix levels were on the lower side.

Thanks, Phillip Schofield, Phillipa Page, Dan Bloomer, and Olivia Webster, for helping with the hand harvest.

A big thank you to all the Operation Advisory Group members who attended our weekly field walks throughout the season, providing us with their expertise and helping make decisions.

Carbon Positive is a partnership between LandWISE, the HB Future Farming Trust, McCain Foods, Heinz-Wattie’s and Process Vegetables NZ. Many thanks to our funders; MPI, Process Vegetables NZ, McCain Foods, Heinz-Watties and Hill-Labs.