Conal’s Pasture Research , Part 1: The First Cut

The first cut is complete. Part 1 brings together fresh pasture weights, Brix readings, earthworm counts and Conal Wattam’s observations from the paddock.

Across all three trial areas, the recorded fresh pasture weights were higher in the Fungal Feeder treatments than in their corresponding controls. Conal also observed substantial soil variation, including within Area 1. Both findings matter when interpreting this first cut.

Read the prequel, Meet Conal Wattam: Fungal Feeder Pasture Research Underway, for Conal’s background and the start of the trial. The comparison follows a control alongside Fungal Feeder applied at 30, 60 and 90 litres per hectare. Part 1 brings the first-cut measurements together with his field observations.

Fungal Feeder was applied on 5 September. The first-cut data were collected on 5 and 6 October, about a month later.

Conal used 1 m² sampling areas and a hedge trimmer. He describes the cut as approximately 2 to 3 cm, intended as a one-off assessment. Each treatment had five samples in Areas 1 and 3, and three samples in Area 2, where the rows were shorter. Each kilogram figure is the combined total from those samples, covering 5 m² per treatment in Areas 1 and 3 and 3 m² per treatment in Area 2.

The table and graphs show the combined fresh pasture weight in kilograms for each treatment within each trial area.

Calculated from the combined fresh-weight totals divided by 5 m² in Areas 1 and 3, and 3 m² in Area 2. Values are rounded to two decimal places.

Trial area 1

In Area 1, the combined control weight was 3.10 kg, compared with 6.50 kg at 90 L/ha. The 30 L/ha weight was slightly above the control, with 60 L/ha between them.

Trial area 2

Area 2 recorded its highest combined fresh weight at 90 L/ha (3.40 kg), followed by 60 L/ha and 30 L/ha. The corresponding control was 1.30 kg. Each total covers three samples of 1 m².

Trial area 3

Area 3 showed a different order for its combined fresh weights. 60 L/ha recorded 3.70 kg, ahead of 90 L/ha at 3.10 kg. The control was 1.10 kg.

The highest recorded weight was at 90 L/ha in two areas and 60 L/ha in the third. These first measurements help guide the next stage of the research. Laboratory results and further replicated trials will help us investigate how application rate, soil conditions and pasture growth relate to one another, and whether the patterns repeat.

Conal’s main observation was the extent of the soil variation, both between Areas 1 and 2 and from one end of Area 1 to the other. In his assessment, the 60 and 90 L/ha plots in Area 1 appeared to have the best soil conditions. His soil observations provide useful context for interpreting the pasture weights.

While looking for earthworms, he also examined how readily the soil broke apart. He reported that some samples in Area 2 were difficult to dig to spade depth and described that area as compacted. He also noted more weeds in its pasture mix, differences in root depth and a lack of visible nodules on the clover roots he inspected.

These photographs and Conal’s field observations give us a starting point for exploring the connections between Fungal Feeder, soil biology, root development and earthworm habitat. The laboratory results and further replicated research will help us test those connections and understand whether the same patterns occur across different soils and growing conditions.

Fungal and bacterial soil testing

Conal is keen to see the soils examined under a microscope and hopes the soil biology testing will help explain the differences he observed. Whether Area 1 has greater biological activity than Area 2 remains a question for the test results.

We are waiting for the Soil Foodweb results, including the fungal and bacterial soil measurements. By matching these results to the trial areas and treatments, we aim to explore how the soil biology relates to the structure, roots and earthworms observed in the paddock. Further replicated research will help us assess how consistently these relationships occur.

A separate random hill sample was sent to Soil Foodweb for interest. It was collected outside the trial and will be kept separate from the treatment comparisons.

A next step: soil eDNA testing

We also want to add soil environmental DNA (eDNA) testing to the next phase of the research. eDNA is genetic material recovered from environmental samples such as soil or water. With suitable soil tests, it can help identify organisms detected in a sample, including fungi and bacteria.

Comparing the DNA detected in treatment and control soils would add another way to explore the differences Conal is seeing in soil structure, roots, earthworms and pasture growth. We would agree a consistent sampling plan with the laboratory and include replicated samples. This is a proposed next step, alongside the dry matter, Soil Foodweb and Hills herbage results already being awaited.

eDNA would help build the picture of which organisms are present. We would interpret that alongside the other tests and field observations to investigate how the soil is functioning.

What is eDNA? Read the New Zealand EPA’s simple explanation.

Brix and earthworm observations

Brix is one clue, not a silver bullet

The Brix results do not show a consistent improvement from Fungal Feeder at this first cut. They add information about the sampled pasture, but do not establish whether its feeding value improved.

Brix is a refractometer reading that reflects the concentration of dissolved substances in plant juice. Sugars contribute, alongside other soluble compounds. Brix is not a direct measurement of sugar content, feed energy or overall pasture quality. Mississippi State University Extension explains the limits of Brix in forage.

These are the mean readings from the first cut:

In Areas 1 and 3, every treated mean was below the control. Area 2 was mixed, with higher readings at 30 and 90 L/ha and a lower reading at 60 L/ha. There is no consistent pattern of Brix increasing with application rate.

The graph shows the number of readings behind each mean. Samples that yielded no juice are excluded.

Why the sampling method matters

• Area 2’s control had only one reading. That makes this comparison particularly uncertain.
• No juice means a missing measurement. These entries are excluded from the means, rather than treated as zero Brix. The resulting means describe the samples that yielded juice.
• Plant species differed. Conal observed higher readings in weeds than grass, so the mix of plants sampled could influence the comparison.
• Averages do not show the full spread. The means alone cannot tell us whether the differences exceed normal sampling variation.

Brix can also vary with the part of the plant sampled, plant maturity, moisture, weather and time of day. Consistent sample selection, juice extraction, instrument calibration and reading conditions are essential for a useful comparison. Mississippi State University’s sampling guidance explains why matching methods and conditions matters.

Inconsistent sampling can produce misleading comparisons and a false impression of a treatment effect. Recording the method and repeating the comparisons helps us separate a possible response from differences in the samples or the way they were measured.

Higher fresh pasture weights were observed in this trial, while the Brix measurements leave feed quality as a question for further testing. Lower Brix readings also do not establish poorer feed quality. In a study of alfalfa and orchardgrass, researchers found that higher or lower Brix did not reliably track changes in laboratory measures of nutritional value. The relationship was particularly weak for orchardgrass. Read the USDA Agricultural Research Service research summary.

Earthworm counts

Conal counted earthworms in spade-depth soil samples as part of his Visual Soil Assessment (VSA). The graph below shows the values entered in the field record.

Area 1 recorded the highest counts at 60 and 90 L/ha. Area 2 recorded low counts, and no earthworms were recorded in Area 3. These observations sit alongside the soil structure photographs and Conal’s account of the variation within the paddock.

The strongest pairing was in Area 1 at 90 L/ha. This plot recorded the highest earthworm count, 14, alongside the highest fresh pasture weight: 6.50 kg across five 1 m² samples, equivalent to 1.30 kg/m². It remained the highest weight after accounting for the smaller sampled area in Area 2.

That pairing gives us a useful connection to investigate between earthworms, soil conditions and pasture growth. Conal also observed substantial soil variation. The dry matter weights, Soil Foodweb results, Hills herbage tests and further replicated comparisons will help us explore how these factors relate and whether the pattern repeats.

This is the first part of the results. The next update will bring in the dry matter weights, Soil Foodweb results and Hills herbage test results as they become available, alongside further observations from Conal. Together with further replications of the research, these results will help us investigate the links between Fungal Feeder use, soil biology and pasture performance.

Conal has suggested checking regrowth after approximately two weeks, although a further cut date has not been confirmed. He also reports that an aeration pass is planned for Area 2. Its timing and coverage will need to be recorded, because that would introduce another management change into any later comparisons.

Watch this space. We will share Part 2 as the laboratory results and dry matter weights become available, building on the first-cut measurements and what Conal is seeing in the paddock.