Chickpeas on heavy soil: Pre-harvest update from the Moora trial
By Kate Parker & Simon Kruger, WMG
The West Midlands Group’s heavy soil chickpea trial at Jim Hamilton’s property in Moora is approaching harvest, providing early insights into how Desi chickpeas perform in a challenging season. The site forms part of the broader GRDC funded, GGA led Grain Legumes Project and is testing whether management decisions such as seeding rate and inoculant loading influence establishment, biomass and nitrogen fixation on heavier country in the West Midlands region.
This update summarises findings to date, drawing on plant counts, biomass cuts, ¹?N analysis and seasonal constraints observed across the site. Final yield results will be reported once harvest is complete.
Trial design and seasonal context
The trial evaluated three treatments of Captain (Desi) chickpeas on heavy soil:
| Treatment | Description |
|---|---|
| Control | 3.5 kg/ha Nodulator, 100 kg/ha seed |
| Double inoculant | 7 kg/ha Nodulator, 100 kg/ha seed |
| Increased seeding rate | 3.5 kg/ha Nodulator, 130 kg/ha seed |
The site experienced one of the most variable starts in recent seasons. Initial seeding on 14 April was followed by unseasonably hot and dry conditions through April and May, resulting in very poor establishment. The paddock was re-seeded on 9 June, after which plant numbers rapidly recovered, reaching target densities by early July.
From late July onward, the seasonal pattern reversed sharply. Rainfall at the nearby Barberton station far exceeded the long-term average in June, July and August, driving prolonged waterlogging in the top and bottom quarters of the paddock. This had a clear influence on crop development, with saturated soil becoming the dominant constraint through flowering and biomass sampling.
| Statistic | Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct |
| 2025 | 1.6 | 5.8 | 10.2 | 20.8 | 24 | 65.2 | 132.7 | 108.6 | 36.4 | 21 |
| LTA (1911-2025) | 13.6 | 16 | 19.2 | 23.6 | 55.7 | 82.8 | 83.9 | 64.5 | 37.8 | 23.6 |
The 2024 soil tests (0–10 cm) indicated moderate phosphorus, high potassium, slightly acidic pH (5.7 CaCl?) and low organic carbon (1.01 per cent).
Establishment after reseeding
Plant establishment was measured twice: after the unsuccessful April sowing (8 June) and following the June reseeding (1 July). After the reseed, all treatments achieved strong and consistent establishment across the better-drained central portion of the paddock.
Figure 1 and 2. Plant establishment 1. Seeded on April 14th, Plant counts completed on the 8th of June. Plants/m2 (left) and Establishment % (right), Recommended establishment % is 80 percent germination of seeds.
While differences were not statistically significant, the increased seeding rate treatment recorded slightly higher plant numbers, aligning with expectations. By early July, establishment percentages across all treatments were close to the recommended 80 per cent germination benchmark.
Figure 3 and 4. Plant establishment 2. Re-seeded (100kg/ha) on June 9th, Plant counts completed on the 1st of July. Plants/m2 (left) and Establishment % (right), Recommended establishment is 80 percent germination of seeds.
Weed pressure
Weed counts taken at early flowering (21 August) showed no significant treatment effect, though the increased seeding rate plots carried marginally fewer weeds. Weed pressure was patchy, reflecting moisture variability and herbicide performance rather than treatment differences.
Biomass development through winter
Early flowering biomass
The first biomass cuts (13 August) showed:
- a clear trend toward higher early biomass in the increased seeding rate treatment
- double inoculant and control treatments performing similarly
- a separate “waterlogged reference” recording very low biomass due to persistent moisture stress.
These early results highlight chickpeas’ strong sensitivity to saturated soils. In low-lying areas, growth was severely restricted, with subsequent drone imagery (10 September) showing stark contrasts between waterlogged and better-drained zones.
Peak biomass
Peak biomass sampling on 7 October revealed a statistically significant treatment effect. The increased seeding rate treatment again produced the highest biomass, clearly above the control and double inoculant treatments.
Waterlogged areas remained far lower in biomass across all treatments, confirming that soil moisture, not inoculant rate or disease, was the primary limiting factor this season.
Nitrogen fixation: a positive result
¹?N analysis conducted pre-flowering showed exceptionally strong nitrogen fixation across all treatments. Despite chickpeas often being considered “lazy nodulators”, the crop derived the vast majority of nitrogen from biological fixation.
| Treatment | % N from atmosphere | N fixed (kg/ha) |
|---|---|---|
| Increased seeding rate | 96.7% | 83.2 |
| Control | 104.8% | 59.4 |
| Double inoculant | 90.0% | 64.7 |
The increased seeding rate fixed the most total nitrogen due to greater plant biomass at the time of sampling. Importantly, these values are likely conservative, as the crop continued to accumulate biomass beyond the sampling date.
Disease observations
No foliar diseases were detected during flowering, and the patchy chlorosis observed in low-lying areas was attributed to waterlogging rather than disease. Fungicide applications were effective, and there was no evidence of Ascochyta or Botrytis infection.
Key learnings so far
Based on the 2025 season to date, the following insights are emerging from the Moora heavy-soil trial:
- Early drought followed by prolonged waterlogging created highly variable conditions across the site.
- Reseeding in June restored plant establishment to target levels.
- Increased seeding rate may improve canopy closure and weed competition.
- Nitrogen fixation was very strong across all treatments, providing a positive contribution to soil nitrogen levels.
- Waterlogging was the major limitation this season, rather than inoculant rate or foliar disease.
- Yield results are still required to determine whether biomass differences translate into grain yield.
- Current yield modelling suggests a potential yield of 4.29 t/ha, although actual values may vary depending on harvest conditions.
Next steps
Harvest results will be available shortly. These will help determine whether the benefits observed in biomass and N fixation carry through to final grain yield and what this means for chickpeas as a rotational option on heavy soils in the West Midlands region.
A full post-harvest report will be released in early 2026, including economic analysis and implications for growers considering chickpeas on heavier soil types.
