Kiwifruit · Variable rate

Variable rate in kiwifruit

Put fertiliser where each part of the block needs it, and prove it went on. Follow one example block from the soil test to the spreader and back.

Six steps, one loop

One example block: 4.0 ha of gold kiwifruit. Under the canopy every part of a block is different. Test it properly and each part can get what it needs, rather than one average rate for the lot.

  1. 1TestGrid soil samples, one bag per point
  2. 2SeeResults on a map, nutrient by nutrient
  3. 3PrescribeA rate map, with a rate for each part
  4. 4SpreadThe spreader changes rate as it goes
  5. 5ProveProof of application comes back
  6. 6MonitorRe-test the same spots each year

Round again: what monitoring shows sets next season’s rates.

A transect gives an average. A grid shows where.

Most blocks are tested with a transect: a zig-zag walk across the block, with every plug in one bag. A grid tests the same block at 16 points, and each one is bagged and analysed on its own.

The same kiwifruit block twice. On the left, a zig-zag transect gives one bag and one number, K 0.70, so the whole block is one colour. On the right, 16 grid points give 16 bags, and the map shows a low corner in the south-west and a high strip in the north-east.
Transect

One walk, one bag of plugs, one number for all 4.0 ha: K 0.70. A good average, but it can’t tell you where.

Grid

16 points, each in its own bag. Now you can see the low corner that needs more and the high strip that already has plenty.

A close-up of one grid point: soil plugs are taken across three rows and four bays around the point, and all of them go into one labelled bag for that point.

How a grid sample is taken

  1. Find the point. The sampler walks to each point with GPS. Each one stands for about a quarter of a hectare.
  2. Plugs from 3 rows × 4 bays. Soil plugs are taken across the three rows and four bays around the point, so the bag stands for that patch of the block, and one odd spot can’t skew it.
  3. One bag per point. Each bag is labelled with its point and analysed on its own: 16 points, 16 bags, 16 results.

Every result, on the map

The lab results are imported against each grid point, and every nutrient gets its own map. Deficient, in range and excess stand out at a glance, graded against the consultancy’s own ranges.

Three maps of the same block. Potassium is deficient in the south-west corner, pH has one low patch in the middle, and magnesium is in excess along the eastern edge.

The patterns don’t line up. That’s why each nutrient gets its own decision, and why one average for the block can hide what’s going on.

The platform shows the data. The advisor makes the call.

  1. The platform

    Shows the data

    Every result on the map, with the block’s history, so the highs and lows are easy to see.

  2. The advisor

    Makes the call

    Writes the recommendation and the annual plan, from the data and what they know of the orchard and the grower’s goals.

  3. The platform

    Carries it out

    Turns the advisor’s rates into a rate map, sends it to the spreader and brings the proof back.

The ranges are the consultancy’s. What counts as deficient, in range or in excess is set by the consultancy, not the platform.

Nothing is prescribed automatically. The platform never writes a recommendation or an annual plan by itself. It makes a better-informed call quicker and easier.

A rate for each part of the block

From the potassium map, the advisor sets a potash rate for each band of soil K. The block is split into 10 m cells, and each cell gets the rate for its result.

The potash rate map for the block: 450 kg/ha in the south-west corner, 300 kg/ha around it, 150 kg/ha across the middle, and no potash in the north-east.

Potash rate map

Soil K in me/100g · potash in kg
Soil KAreaRatePotash
Below 0.45 0.23 ha 450 kg/ha 104 kg
0.45 – 0.60 0.88 ha 300 kg/ha 264 kg
0.60 – 0.80 1.73 ha 150 kg/ha 260 kg
0.80 and over 1.16 ha None 0 kg
Total4.00 ha628 kg

The rates are the advisor’s call for the crop. The map just puts each rate where it belongs.

The spreader changes the rate by itself

  • The map goes to the spreader. Straight onto the contractor’s job list, or as a file for their controller.
  • The rate changes as it drives. GPS tells the controller which zone it’s in, and the rate steps up or down at each boundary.
  • Nobody touches a dial. It’s off on the headland and back on at the next row.

In the clip: 300 → 450 → 300 → 150 kg/ha along one row

What the spreader applied, pass by pass down the alleys, coloured by rate and laid over the zones of the plan. It followed the map, with short ramps where the rate changes.

Proof of application comes back

627 kgapplied
628 kgplanned
  • What went on, where and when. The spreader’s record comes back to the platform after the job.
  • Laid over the plan. You can see it went where it was meant to.
  • Kept with the block. Ready for an audit, or for next season’s plan.

One average rate: too much here, too little there

With only the transect’s 0.70 to go on, 150 kg/ha everywhere is the sensible call. Lay that flat rate over what the grid found.

The flat rate laid over what each part of the block needed: the north-east got 150 kg/ha it didn’t need, the middle was about right, and the south-west was short, by up to 300 kg/ha in the corner.
  • 150 kg/ha too much1.16 ha · soil K 0.80 and over
  • About right1.73 ha · soil K 0.60 – 0.80
  • 150 kg/ha short0.88 ha · soil K 0.45 – 0.60
  • 300 kg/ha short0.23 ha · soil K below 0.45

About the same potash. A very different result.

Transect · 150 kg/ha everywhere
600 kg

174 kg on 1.16 ha that didn’t need it, and 1.11 ha left 201 kg short.

Grid · four rates
628 kg

All of it where the soil test said it was needed.

Potash rate in each part of the blockkg/ha
Potash rate in each part of the block, kg/ha
Soil KAreaTransectGrid
Below 0.450.23 ha150450
0.45 – 0.600.88 ha150300
0.60 – 0.801.73 ha150150
0.80 and over1.16 ha1500

On some blocks the grid saves product, and on others it uses a little more. Either way, it goes where it does some good.

An example variable-rate fertiliser programme

Straight fertilisers in place of mixed products where possible, then side dressings at key points in the season. A mix moves every nutrient up and down together; with straights, each nutrient can follow its own rate map.

  1. Base dressing

    Correct variability

    Two to three passes of straight products

    Each follows its own rate map, moving every part of the block towards the optimum range.

  2. Side dressing 1

    Bud break

    YaraMila Complex Blend or Advantage Bud Break

    Supports strong early growth as the vines come out of dormancy.

  3. Side dressing 2

    Pre-flowering

    Yara Rega or Advantage Pre-Flower

    YaraLiva Nitrabor + SOP

    Key nutrients for cell division, flowering and fruit set.

  4. Side dressing 3 · optional

    Crop load

    YaraMila Complex or Advantage Post-Flower

    Where required, for dry matter, fruit sizing and crop load.

Where the soil needs itThe variable-rate base dressing evens out the block.
When the vine needs itSide dressings at the stages that set the crop.

An example only. The products, rates and timing are always the advisor’s call.

Then keep an eye on it

You don’t need a full grid every year. A few of the same grid points are re-tested each year as monitoring samples, then a full grid redraws the map every four to five years.

Five years of the same block. Year 1 is a full grid of 16 points. In years 2 to 4 the same four points are re-tested, and the low corner climbs from 0.28 to 0.33 to 0.38 to 0.42. Year 5 is a full grid again, and the deficient corner has shrunk to a small patch.

Year 1 · Full grid

Every point tested. This sets the map and the first rate map.

Years 2–4 · Monitoring samples

The same four grid points, one in each rate zone, so the numbers compare like for like. The low corner climbs: 0.28 → 0.33 → 0.38 → 0.42.

Year 5 · Grid again

Every 4–5 years, a full grid redraws the whole map.

See it on a 30-minute call

We’ll follow an example orchard from the grid test to proof of application, then talk about your business.

Book a demo

Example orchard · illustrative figures, not agronomic advice.

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