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.