Thanks to everyone who made LandWISE 21 such a successful Conference!
We were a touch nervous after Covid-cancelling last year, but so heartened when our sponsors jumped on-board, and delgetaes began registering earlier than usual. Perhaps there was a vacuum . . .
The speakers’ presentations are summarised in a series of blog posts, many with a short sound clip. The time put in to create the presentations is clearly huge, it is a very large gift each one makes. Thanks each and every one of you!
Dan Bloomer is LandWISE Manager and a consultant working with and between farmers, scientists and regulators. He likes to be “linking thinking from the farm out”.
Through the MPI SFF project, “Future Proofing Vegetable Production”, Dan, Georgia O’Brien and Luke Posthuma worked with growers to identify ways to minimise nitrate leaching from vegetable production areas.
In this LandWISE 21 Conference presentation, Dan will describe the four strands they set out to address: Precision Prescription, Precision Application, Maximum Retention and Nutrient Mitigation, and the processes for achievement they employed.
The LandWISE team has observed a significant shift in grower thinking and practice. This came when growers were supported with easy to access and use tools and one-on-one coaching.
Stephen Collins is a groundwater scientist for Horizons Regional Council where his job involves managing the monitoring and research aspects of the region’s groundwater resources. A particular research interest of his is understanding land use effects on water quality, which has culminated into him undertaking a PhD part-time.
Stephen’s research is on refining estimates of subsurface nitrogen attenuation. At LandWISE 2021, he discussed nitrogen attenuation and how more accurate predictions of it can help improve overall catchment management.
Abstract:
Subsurface nitrogen attenuation – a key unknown in modelling catchment-scale water quality scenarios
1Massey University, Farmed Landscapes Research Centre (FLRC), Palmerston North
2Horizons Regional Council (HRC), Palmerston North
Subsurface nitrogen attenuation is a measure of how much nitrogen is removed in the subsurface environment below the farm root zone, varying from very low rates in some places, to very high rates elsewhere. In other words, some land units appear more resilient in dealing with nitrogen losses compared to others.
An effective understanding of where and when subsurface nitrogen attenuation occurs, and by how much, can have a significant impact on the way nitrogen losses to waterways are modelled and managed in a catchment, especially when water quality improvements are needed.
Where water quality improvements are required, catchment-scale water quality scenarios need to be developed that take account of attenuation dynamics. However, subsurface nitrogen attenuation appears to be spatially variable across different hydrogeological settings, leading to uncertainty in the modelling of those scenarios. Therefore, a robust method of predicting the spatial variability, and potential rate, of subsurface nitrogen attenuation across different hydrogeological settings in agricultural catchments is needed.
The primary nitrogen attenuation pathway in subsurface environments is denitrification, a microbially-facilitated biogeochemical process that reduces nitrate into predominantly ‘benign’ di-nitrogen gas. This process is governed by a range of physical, chemical and biological characteristics that influence ‘reduction-oxidation’ (redox) conditions in hydrogeological settings. Subsurface redox conditions can broadly be described as either reduced (where dissolved oxygen is low) or oxidised (where dissolved oxygen is abundant). Denitrification mainly occurs in reduced conditions.
Though the science of subsurface denitrification processes is being increasingly studied and better understood, the challenge yet remains to achieve a robust method of predicting the spatial variability, and potential rate, of subsurface nitrogen attenuation across different hydrogeological settings.
Direct measurements of denitrification is practically complex and resource intensive, and therefore not easily measurable over large spatial scales. However, the opportunity to meet this challenge potentially comes from the ability to use easily measurable groundwater quality parameters to assess groundwater redox conditions as a suitable proxy for nitrogen attenuation in subsurface environments. Further, groundwater redox conditions show a strong relationship with some landscape attributes such as soil drainage, permeability, rock type and soil texture.
To aid this research, Massey FLRC and HRC are collaboratively investigating how to refine, measure and account for subsurface nitrogen attenuation in New Zealand landscapes to inform modelling of catchment-scale water quality scenarios.
Phillip Schofield is a soil scientist and rural professional, working with growers and farmers, helping them improve soil function and hence profit.
He holds a B Ag Sci (hons) and a PhD, is a Certified Nutrient Management Advisor and Certified Green House Gas Advisor. Phil is a founding Board Member of the HB Future Farming Charitable Trust.
Phil provides farmers and growers with soil health advice and adapt production systems to improve farm performance and profitability in the face of increasing compliance and regulation.
At LandWISE 21, he asked: Why is soil carbon important? How might we increase it?
Atmospheric CO2 is a greenhouse gas, responsible for global warming. The IPCC reports that soil holds two to three times as much carbon as the atmosphere, so the 4.5 billion ha of pastures and croplands are an immense source or sink.
Plants fix carbon dioxide by photosynthesis, and this provides a mechanism to move CO2 from the atmosphere to the soil. Human activities release about 9 GT C/yr. so increasing soil carbon by 0.4% would account for much of our emissions. It would also improve soil health and set us up better for climate change. Atmospheric CO2 can be sequestered. Plants exude 30% of their sugars through their roots, providing energy and raw materials for synthesis by other organisms.
Soils that contain more carbon have more humus to hold particles together, provide a better environment for root growth, hold more nutrients and hold more water. However, many of our current practices degrade soil. Regenerative practices address soil health by minimising disturbance, keeping the soil covered, always keeping living roots in the soil, increasing plant diversity and introducing grazing animals.
The HB Future Farming Trust aims to establish a series of trials partnering with industry, HBRC, CRIs and MPI. One set is a replicated trial proposed for the LandWISE MicroFarm, with further demonstration trials on orchards, vineyards, and arable and vegetable properties.
Trial sites will be heavily monitored, benchmarking soil physical, chemical and biological properties, nutrient and GHG budgets, water, energy and financial analyses of the enterprises.
Tom Skerman is a self-described “jack of all trades, master of none” who has relished the opportunity to view the primary sector from a number of different viewpoints.
In addition to farming business interests he has practised Law and worked as a commercial development manager for the Maori Trustee, Te Tumu Paeroa, identifying, analysing and executing commercial opportunities for owners of Maori freehold land.
Tom is an investor in a Waikato sheep and beef farming syndicate, a director and shareholder of farm financial software company Figured, an independent director of a foreign-owned NZ forestry and commercial property company and was previously the independent Chair of a pipfruit investment syndicate in the Esk Valley.
In 2016 Tom received a Nuffield Scholarship which, after several months of international travel focussed exclusively on the world of agriculture, culminated in his report “Agribusiness Governance – Finding the Green Zone.”
Tom joined Hawke’s Bay Regional Council in 2013 to work with the Ruataniwha Water Storage Project giving him a front-row seat to the environmental issues and tensions challenging the primary sector. In 2017 he was appointed to the executive team as Group Manager Strategic Planning, which includes responsibility for progressing Hawke’s Bay’s policy and regulatory framework for natural resource management, including all things freshwater.
LandWISE runs on a voluntary membership basis with an annual subscription of just $100 for the current year. Subscriptions are now due and our Financial Members will be getting their invoices sent out shortly.
If you are already one of our Financial Members, Thank You! Can you please help us again by recommending us to a friend?
We haven’t changed our subs for years, but are starting to review that. What would be best, is if more of our followers chose to join!
If you’re getting and valuing our newsletters, downloading and listening to our podcasts, accessing the resources on our website or the FertSpread tools etc. please think about giving us a hand. It really will only cost you about half a cup of coffee a week, but it will make a big difference to us.
How does LandWISE fund its activities?
Our overheads are kept rock-bottom. The MicroFarm, our offices and equipment are provided as an in-kind service by Page Bloomer Associates. Our Board is voluntary, and we meet mostly by email and video conferencing. But we do need to pay accountants and insurance and run websites and the other things every organisation has to do.
Our major activities are funded on a project by project basis. That means we need a lot of support from co-funders so we can access (hopefully) various reasearch and extension grants such as MPI’s Sustainable Food and Fibre Futures fund (SFFF). Our Conference too (as podcasts in 2020!) also relies on a number of loyal sponsors and the delegate fees we collect.
Merf explaining cover crops and catch crops at the LandWISE AGM
All these things cost a bundle. If we can get more members, we can increase the amount of work we can self-fund and provide more member services.
Please consider becoming a Financial Member today. Click the link, fill it in and we’ll flick you an invoice. (and we’ll cover the cost of our own coffees!)
Fernando has a background in edge of field treatments to reduce nutrient losses from cropping systems. He studied the use of vegetated buffer strips to prevent nitrogen losses from maize paddocks, and is now working on a range of N loss mitigation trials in the Horowhenua district of Manawatu.
Vegetated buffer strips can help to prevent nitrogen losses from farming land, thus protecting nearby water resources. The main aim of Fernando’s Chilean study was to assess narrow buffer strips (5 m) wide of different species effectiveness in removing nitrogen forms that flow from cultivated maize fields towards surface water bodies.
During the second year after establishment, variable N loads were estimated from nitrate-N (NO3-N) and ammonia-N (NH4-N) concentrations measured at 1 m depth during the study period. Fernandos’ trial had five treatments: a strip of grass, a strip of grass and a row of native shrubs (Fuchsia magellanica); a strip of grass, a row of shrubs and a row of native trees 1 (Luma chequen); a strip of grass, a row of shrubs and a row of native trees 2 (Drimys winteri); and bare soil as control. The experiment was set in two cultivated maize (Zea mays) fields located in the commune of Pichidegua, Región de O’Higgins. In a clay loam, buffer strip outlet nitrogen measurements from subsurface lateral flow ranged from 10 to 105 kg N ha-1. All treatments were more effective in N removal than the bare soil control treatment and with the grass strip, row of shrubs, and row of native trees treatment performing the highest N removal.
Many thanks to our sponsors who supported the recording and publication of our podcast series.
Our latest podcast is now online. Phillip Schofield talks with Georgia about the role microbes play in soil plant interactions, the use of Visual Soil Assessment (VSA) and practical ways to improve soil health on-farm.
Phillip is a soil nutrition consultant based in Hawke’s Bay. He has a PhD in Plant Science from Massey University where he studied autotoxins, herbicide residues and pathogenic fungi in asparagus crops. He has many years’ experience in soil conservation, and nutrient management in the Hawke’s Bay area.
Our thanks to our loyal sponsors and to Radio Kidnappers for support with our podcast series.
Calling all followers and friends of LandWISE, we invite you to become a financial member this year.
Your support is vital for LandWISE to continue doing what we do. We rely on farmer support to ensure the backing of new projects, discover new areas for research or technology adoption, and to fund field days, workshops and the development of practical resources.
LandWISE Membership is a great way to support the mission of sustainable production in New Zealand, and as a member you’ll benefit from:
Results from on-farm trials
Projects focussed on real farmer and grower problems
Regional field days and workshops on a range of topics from conserving soil to nutrient management and novel fertiliser technology
A discounted registration at the 2021 LandWISE Conference
Subscription to our annual LandWISE News publication
Membership is open to all who are interested in primary production and share our values. We hope you’ll consider becoming a member, or forward this on to a non-member if you already are!
The Efficient Irrigation workshop and IRRIG8 Quick bucket-test field demonstration we ran for Gisborne Irrigation Operators and Crop Managers was well attended. We were pleased to have industry and council staff also attending the day.
Many thanks to Leaderbrand for continuing their support for our Gisborne activities and setting up their irrigators for the bucket test demonstration. A great group of staff getting stuck-in and learning as much as possible about good practices.
We started the day with a slide presentation at the Bushmere Arms, discussing the many different definitions of “Irrigation Efficiency”. Efficient Irrigation is a critical input for high-value cropping systems. Getting it right or wrong can make or break crop yields, quality, and nutrient management targets. Dan noted that when most people are talking about efficiency they mean Application Efficiency: how much of the water applied to a field was held in the soil and avilable for plants for growth.
To get high application efficiency, application should be as uniform as practically posssible, and the depth applied should only be enough to refill most of the root depth. Low efficiency means excess water is applied, a sign that leaching risk is increased.
The IRRIG8 Quick calibration methods uses 20-24 9L buckets, spaced across the irrigation application area. Different bucket positions are used depending on the type of irrigation being tested. At this worshop, we tested one of Leaderbrand’s boom irrigators.
We also demonstrated the IRRIG8Lite software that runs on a PC. This is a free resource from Page Bloomer Associates. It takes care of all calculations required and produces printable reports including a graph of application depth across the irrigation area.
Stephen Collins is a groundwater scientist for 
Tom Skerman is a self-described “jack of all trades, master of none” who has relished the opportunity to view the primary sector from a number of different viewpoints.
In 
Our 
