Tag Archives: MicroFarm

Onion Crop Development

The crop at the MicroFarm is showing increasing variability.  The cause of some is understood, essentially excessive water pre-germination.  But in some poor performing areas the causes have yet to be determined.

The effect of our artificially applied rain event pre-emergence is clearly evident in late November.

The lasting effect of a heavy (artificial) rain event pre-emergence (right panel) shows low population and poor growth compared to areas without heavy rain (left panel)
The lasting effect of a heavy (artificial) rain event pre-emergence (right panel) shows low population and poor growth compared to areas without heavy rain (left panel)

However, we also see other areas that have poor crop development that are outside the area irrigated to create the artificial rain event.

Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns.
Wide variation within the area new to onions does not follow artificial rain or topographic drainage patterns.

Sharp differences in crop growth are evident in the new onion ground. Some parts that were heavily irrigated to simulate heavy rain show reasonable development. Areas that were not irrigated also show good development, but in some patches total crop loss.

Investigations of soil physical properties in these different areas are underway.

Onion Crops Sown

As part of our ongoing research project with Onions New Zealand, a new crop was sown on 6 September 2016.

Sowing onion seed at the MicroFarm
Sowing onion seed at the MicroFarm

Harvey from G & J Steenkamer planted the crop using Rhinestone seed donated by Vigour Seeds and treated for us by Seed and Field Services. We are very grateful for their continuing support.

We’ve aimed at a population of 580,000 plants/ha. With 8 rows in our 1.82m wide beds, we have seed at 72mm spacing in the row.

G& J Steenkamer sowing our onion crop.

After last harvest the beds, but not wheel tracks, were ripped to 450mm depth.  Autumn planted Caliente and oat cover crops were mulched and incorporated in late June and the ground left fallow.  Prior to sowing it was hoed and rolled.

Rain after planting had only minor impact, with a little soil capping in some areas.


Scouting by Consumer UAV

Consumer UAVs are increasingly seen as farm tools.  Some come with camera and packaged tech for easy flying, pretty much straight out of the box.

But before you leap in, please be aware there are RULES.

We suggest you spend time on the AirShare www.airshare.co.nz and CAA www.caa.govt.nz/rpas/ websites before you get started.  Designed specifically for UAV users they have easy to digest information setting out what you can and cannot do.

DJI Phantom 3

Our package came with all equipment, an extra battery and optional propeller guards packed in a tough custom carry case.  The camera is on a gimbal for steady shots, panning and tilting. Zoom in by getting closer!

A downloaded smartphone or tablet app shows flight information such as height, position and battery charge and lets you see exactly what the camera sees with no delay.

In windy conditions, we achieved about 13 minutes of flight time rather than the 23 minutes stated for each battery charge. Rules say you must be able to see the aircraft with your own eyes so you are probably limited to under 100ha. You could make a reasonable inspection in that time.

Peas and onions from 30m Web

We used the UAV to scout at the LandWISE MicroFarm. Viewed from 30m up, crop variation is immediately obvious.  Pea flowering striping seems to match drill widths. We had variable emergence too so ponder the link. Sprayer runs are visible too.

On the onion side we see thinner areas to the bottom right, and patches where Plant & Food have harvested sample plants as part of our joint OnionsNZ research project.


Viewed from directly overhead we see more of Plant & Food’s research plots, some harvested and some still being followed through to final harvest. The image indicates all these plots are within a reasonably good and even part of the crop.

To the bottom right, a lower wetter area shows lower populations where plants are smaller and fewer made it through establishment.


Dropping to a metre of two above the crop and tilting the camera, we see up close. Because we are seeing what the camera is seeing, we can choose exactly what we want to check and go there immediately.

So we’ve scouted the whole paddock, had a closer look here and there, and if we need to, we can walk to the spots we want to check in detail. The thing is, we know where we should be looking.

Satellite Imagery

A large part of Heretaunga Plains horticulture was photographed for us by satellite at the end of November.

World View 2 satellite coverage of the Heretaunga Plains on 23 November 2105
World View 2 satellite coverage of the Heretaunga Plains on 23 November 2105

Part of our OnionsNZ Variability project, the World View 2 coverage targeted our crop and other onion crops east of Hastings.

By capturing four bands of light, Blue, Green, Red and Near Infrared, we are able to get a “normal” colour image like an aerial photo, and a biomass map using the NDVI index.

The satellite image pixel size in 0.5m x 0.5m, so we get at least two pixels across each onion bed.

World View 2 NDVI image captured 23 november 2015 of MicroFarm onion and vining pea crops
World View 2 NDVI image captured 23 November 2015 of MicroFarm onion and vining pea crops

In the NDVI image, the onion crop is lower left paddock, the vining peas upper right. Red areas indicate low or no biomass, yellow light, green moderate and blue heavy cover. Note however that the value of each colour is slightly different for each crop.

Because the pea canopy is full ground cover while the onions are only roughly half ground cover, we had to use different value bands to see variation within each crop. If we used the same range, either the peas would all be blue, or the onions mostly yellow and red.

The striping effect in the onions is the onion beds. Some adjacent beds have quite different canopy densities.  The red edge around the onions is bare soil and light canopy in the outer beds. The blue area in the centre is influenced by charcoal from an old bonfire site. Even taking these things into account, there is a reasonably large amount of variation in this crop.

Red spots in the pea crop are patches with no plants. The red headlands show light canopy areas and the red strip centre right the irrigator access track. There are three different seed lines of Ashton peas making up the pea crop. These are not discernable in the satellite image. The crop was harvested on 14 December, and there was no significant difference seen in hand harvested plots or in the viner.