Category Archives: Projects

Onions Update Field Walk

LandWISE MicroFarm
21 Ruahapia Rd, Waipatu, Hastings
Monday 11 December 2:00pm

In our final year of “Benchmarking Onions” we have again planted a crop at the MicroFarm. It went into a suitably moist soil, emerged reasonably evenly but has shown increasing variation. We now have very good areas and very disappointing areas. 

We’ve mapped the crop with our CoverMap system again this season so we can compare 2015-16, 2016-17 and 2017-18 growth patterns. Are there areas that consistently perform better or worse? What is driving the variation we see?

We also have a few different varieties we are tracking to see how canopy development fits our web calculator. We want to know if the same calculations can be applied to phone images or if variety-based tweeks are necessary.

In a couple of fertiliser application trials we comparing standard and late application because we understand most nitrogen is taken up at or after bulbing. And based on our mapping, we are comparing the effects of full and half rates on areas where canopy cover is low. Maybe we can cut back, save fertiliser and leaching and get the same yield with improved bulb quality.

Come along and see for yourself!

Note: This field walk follows the HotGrass electric weeding demonstration, see more here>

Our Onion Research is in conjunction with Plant and Food Research. It is funded by Onions NZ and the Sustainable Farming Fund. This season we are being aided by Apatu Farms who are helping with field operations and harvest and we are very grateful for their support.


Field Scale Electric Weeder Consortium

Do you have an interest in field scale electrothermal weeders and being part of a project to make that happen?

Charles Merfield is leading a proposal to develop equipment in conjunction with Ubiqutek,  a UK company who originally designed electric weeders and have weeders in use in the UK and HotGrass, the NZ agent. 

The current commercial machines are ‘only’ hand held weeders aimed at the urban weed control market, e.g., councils, and their contractors.  However, the handheld machines can clearly demonstrate the potential of electrothermal, and Kazel Cass of Hotgrass, is doing a series of demonstrations around the country which you may be interested in attending.

If you would like more information about electrothermal weeders have a look at the FFC Bulletin article.

In any normal situation, Ubiqutek and Hotgrass as the owners / suppliers of the weeders would be developing field weeders themselves, however, both are very small business startups with limited funding and people resources, so they are unable to start work on a field machines for several years.  They also lack expertise in what is required from field machines especially for the different sectors, e.g., pasture, cropping, viticulture and other permanent crops, and therefore how to design them. 

The aim of Charles Merfield’s project is to accelerate the development of a field scale weeder so that NZ farmers & growers get access much sooner. To do this he is seeking farmers and growers who are interested in the technology and willing to contribute some funding. 

For more details, contact Dan at LandWISE or Charles Merfield at the Future Farming Centre.


MicroFarm Update

Some important “Thank you”s:

For the last three seasons, Gerry Steenkamer and family have supported our onion growing and the OnionsNZ Sustainable Farming Fund project on Benchmarking Variability. Without their help we wouldn’t have even had a crop and seen the variability in it in the first place. Since then we’ve been dependent on them for prep and planting, harvest and marketing the crops we’ve produced. We are extremely grateful for that. Many, many thanks Gerry, Jenny, John and all the staff who have done great work for us. It has been a privilege.

This year Apatu Farms have come on board to help us with our final year of the Benchmarking project. So, many thanks too Mark and Paul and your staff who are helping us this season. We especially appreciate fitting our very small but time consuming job into your schedule during a very difficult planting season. With seven different varieties planted, it took even longer than normal, but we are thrilled with the job done.

Two years ago we borrowed a tractor from Mike Glazebrook for a few months. After two seasons, we’ve returned it but also thank Mike and Nigel for their help with MicroFarm activities. The main role of this machine was carrying our sensors, then towing a small spray trailer over our onions. It was an ideal fit, but is now needed again at its true home! Thanks Mike and BioRich.

To replace the BioRich tractor we’ve picked up an older John Deere 2030. To fit the Apatu Farms standard bed we’ve been getting the wheels out to run on 2 m wide beds. That took a little work, but it’s now all go.

This project is a collaboration with Plant and Food Research for OnionsNZ with support from the MPI Sustainable Farming Fund.

Benchmarking Onions Year 3

The final year of our collaborative project with Plant and Food Research for OnionsNZ with support from the MPI Sustainable Farming Fund is underway.

This season we are linking with regional agronomists and farmers in Pukekohe/Pukekawa, Hawke’s Bay and Canterbury to further test the Management Action Zone tools.

One of the Pukekawa crops is most advanced and our mapping there starts very soon. Our aim is to map crops at 3 leaf stage, use that to identify canopy zones and take photos in each zone for detailed analysis.

The ground area calculated from the photos is added to plant population counts and run through a crop development model on to predict final yield in each zone. The model also identifies if population of plant growth rate are causing lower than expected development, and therefore yield.

This field is almost ready for the first mapping exercise. We are somewhat nervous because the weeds can cause errors: green is green! Sometimes we can filter the weeds out of the images, but if there is very little difference between weed and onion, it is not yet possible.

The MicroFarm crop has started to emerge in recent days. We are keeping an eye on this to see what impact emergence has later.

LandWISE 2017: Are we ready for automation?

In 2017 our 15th Annual Conference focuses on automated tools for data collection, decision making and doing actual tasks on the farm (and beyond).

  • What do you want?
  • What’s on offer?
  • How will farms and management have to change?

We have a comprehensive programme. We’ve gone a bit outside the box to bring a variety including from outside the horticultural and arable sectors. We find cross-pollination and hybrid vigour valuable!

So register, come along and listen to excellent presenters, discuss the ideas with colleagues and go away with new understanding and plans.

Thanks to Our Loyal Platinum Sponsors!
Many thanks to AGMARDT, sponsors of our international presenter, Thibault Delcroix, France

Hawke’s Bay Regional Council, John Deere and BASF Crop Protection are our Platinum Sponsors again in 2017. Many thanks to these loyal supporters who have backed the Conference for a number of years.

We also welcome our Gold Sponsors, meal sponsors and  trade displays new and old. These are the organisations that make conferences like this possible and affordable.

Join them and us at the Havelock North Function Centre on 24-25 May 2017 to mix with leading practitioners, farmers, growers, researchers, technology developers and providers.

Register now – click here!


Benchmarking Onion Variability 2016-17

Now in year two of our OnionsNZ SFF project, we have trials at the MicroFarm and monitoring sites at three commercial farms in Hawke’s Bay and three more in Pukekohe.


A summary of Year 1 is on our website. A key aspect was testing a range of sensors and camera systems for assessing crop size and variability. Because onions are like needles poking from the ground, all sensors struggled especially when plants were small. This is when we want to know about the developing crop, as it is the time we make decisions and apply management.

By November our sensing was more satisfactory. At this stage we captured satellite, UAV, smartphone and GreenSeeker data and created a series of maps. 

We used the satellite image  to create canopy maps and identify zones. We sampled within the zones at harvest, and used the raltioship between November canopy and February yield to create yield maps and profit maps.

Yield assessments show considerable variation, limits imposed by population, growth of individual plants, or both

We also developed relationships between photographs of ground cover, laboratory measurements of fresh weight and leaf area and the final crop yield.

In reviewing the season’s worth of MicroFarm plot measurements and noticed there were areas where yield reached its potential, areas where yield was limited by population (establishment), some where yield was limited by canopy growth (development) and some by both population and development.

This observation helped us form a concept of Management Action Zones, based on population and canopy development assessments.

Management Action Zones – If population is low work for better establishment next season. If plants are small see if there is something that can be done this season


Our aims for Year 2 are on the website. We set out to confirm the relationships we found in Year 1.

This required developing population expectations and determining estimates of canopy development as the season progressed, against which field measurement could be compared.

We had to select our “zones” before the crop got established as we did a lot of base line testing of the soil. So our zones were chosen based on paddock history and a fair bit of guess work. Really, we need to be able to identify zones within an establishing or developing crop, then determine what is going on so we can try to fix it as quickly as possible.

In previous seasons we experimented with smartphone cameras and image processing to assess canopy size and relate that to final yields. We are very pleased that photographs of sampling plots processed using the “Canopeo” app compare very well with Leaf Area Index again this season.

Through the season we tracked crop development in the plots and using plant counts and canopy cover assessments to try and separate the effects of population (establishment) and soil or other management factors.

We  built a web calculator to do the maths, aiming for a tool any grower or agronomist can use to aid decision making. The web calculator was used to test our theories about yield prediction and management zones.

ASL Software updated the “CoverMap” smartphone application and we obtained consistent results from it. The app calculates canopy ground cover and logs data against GPS position in real time. Because we have confidence that ground cover from image processing is closely related to Leaf Area Index we are working to turn our maps into predictions of final yields.

Maps of canopy cover created from the CoverMap smartphone application show significant variability across the paddock. Canopy increase is seen over time in two maps created a week apart

The current season’s MicroFarm crop is certainly variable. Some is deliberate: we sat the irrigator over some areas after planting to simulate heavy rain events, and we have a poorly irrigated strip. We know some relates to different soil and cover crop histories.

But some differences are unexpected and so far reasons unexplained.

Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns. This photo is of the area shown far right in the cover maps above.

Together with Plant and Food Research we have been taking additional soil samples to try and uncover the causes of patchiness.

We’ve determined one factor is our artificial rain storm, some crop loss is probably runoff from that and some is historic compaction.  We’ve even identified where a shift in our GPS AB line has left 300mm strips of low production where plants are on last year’s wheel tracks!

But there is a long way to go before this tricky crop gives up its secrets.

This project is in collaboration with Plant and Food Research and is funded by OnionsNZ and the MPI Sustainable Farming Fund.

We also appreciate the support of growers, seed companies and our MicroFarm sponsors Ballance AgriNutrients, BASF Crop Protection and the Centre for Land and Water.


MicroFarm Update

Ballance AgriNutrients and BASF Crop Protection have continued their sponsorship of the LandWISE MicroFarm for 2016-17 and 2017-18. The MicroFarm is hosted by the Centre for Land and Water which provides fields, sheds, equipment and the Green Shed venue for our meetings and seminars. We greatly appreciate their very significant contributions which make the operation possible.

Mark Redshaw put hours into getting the MicroFarm up and running and spending much of his free-time spraying and monitoring onions for two seasons. Now we have our own small sprayer we have taken that task over, but remain most grateful to Mark.

Special thanks also to Mel at HydroServices for irrigation monitoring, Patrick Nicolle for machinery support, BioRich for lending us a tractor, Hugh Ritchie for his irrigator, FruitFed Supplies for crop protection support, Scott Lawson for seed and machinery, Vigour Seeds and SPS for onion seed and McCain Foods for process crop support.

After a number of years of constant pea crops, we are having a break. Our main focus this season has been on onions, crop variability and its drivers. We have plenty of variability, but which factors are driving still proves elusive.

Aerial view of the MicroFarm taken by DJI Phantom showing replicated soil amendment plots on right, flagged replicated plots in onion zones on left, and at far left drought stressed onion beds, the reason we extended the irrigator

In conjunction with OnionsNZ and Plant & Food,
we held a grower field day in January to discuss the OnionsNZ SFF project.

We do know topography and drainage are critical factors but they do not explain all the variation we are seeing. To assess their impact, we deliberately applied “heavy rain” to some areas and have been comparing these with areas not subjected to a hard40+mm rain event before emergence.

Artificial heavy rain event applied after planting and before emergence

We prepared an OptiSurface plan two years ago but did not implement it as we were keen to explore variation in our onions trials. Perhaps it is time to act on our own advice!

Topomap created from a Trimble RTK GPS survey shows relative elevations. Yellow highest, purple lowest. Surface flow analysis of topographic maps like this show where water can become trapped and pond.
OptiSurface analysis shows where water will pond. In this image, the beds are assumed to be 100mm high. The brown areas will drain, blue and purple areas will have ponding – pale blue least, dark purple most.

The other main crop this season is sweetcorn. We are hosting a series of variety trials and are assessing a soil amendment product to see if it offers an economic advantage to growers.

To assess the soil amendment we set up a six plot replicated trial – with and without the treatment. We randomly split plots to avoid bias, and are taking crop development data through the season. At harvest we will determine paddock yield and the recovery rate of kernels in each plot.

A randomised six plot trial layout for assessing the effect of a soil amendment on a sweetcorn crop. Yellow lines imposed on aerial image from consumer UAV.

Drainage and Erosion Planning

The Arawhata Catchment Integrated Storm Water Management project is drawing to a close, the majority of work is done but farm follow-ups continue. The aim of the project was to reduce crop loss from ponding and minimise erosion of soil to Lake Horowhenua. 

We completed OptiSurface drainage analyses for 26 Levin properties covering 450ha of intensive vegetable cropping. OptiSurface calculates flood patterns and erosion risk and creates cut & fill maps for GPS levelling. An example is shown in our earlier post “Mapping for Drainage”.

Drainage and Erosion Management Plans were developed for each block. The plans identify drainage problem areas and erosion risks and recommend management strategies to respond.

Individual farms have done significant work to prevent erosion and reduce crop damage. Farmer actions to reduce sediment runoff and ponding include realigning bed direction, levelling, grassed headlands and drains and swales and sediment traps.

Stages in headland redevelopment

Original design used narrow headlands subject to pugging in wet weather with high risk of slumping soil into vegetation-free drains
Headland lowered to ensure adequate drainage from furrows. Vegetation being encouraged to protect drain from sediment inflows
Land-shaping created a much wider headland for a greater vegetation buffer between cultivated land and drains
Completed headland with its well-established vegetated buffer filtering sediment from drainage water

Now farms are required to have consent in this catchment, the Drainage and Erosion Management Plans are a useful component of the overall Farm Nutrient Management Plans required.

Fertiliser Spreader Calibration

We successfully completed our SFF project “On-farm Fertiliser Spreader Calibration” and launched the online tool, earlier this year.

Some key messages:

  • Our testing found wide performance variation
  • Most new machines do a good job if set up correctly
  • Caution is essential spreading blended fertilisers or when bout widths exceed 30 m
  • Visible striping indicates > 40% application variability and at least a 20% yield penalty.
  • Fertiliser ballistics play a critical role
Setting out a line of catch trays to test fertiliser application uniformity
Driving over a line of catch trays

We ran a number of workshops from Waikato to Ashburton reaching a wide range of farmers and industry people. Information, training handouts and how-to YouTube video clips are on the LandWISE website. See for the on-line calculator and field recording sheets.

We are grateful for strong support from Miles Grafton and Ian Yule at Massey University.

This project was co-funded by the Foundation for Arable Research (FAR), the Fertiliser Association (FertResearch) and MPI Sustainable Farming Fund.

More at