Chickpeas on heavy country: what the 2025 Moora season showed

By Simon Kruger, WMG Project Communications Officer

Harvest is complete at Jim Hamilton’s chickpea trial site near Moora, concluding a 2025 season that included failed establishment in April, reseeding in June, and prolonged waterlogging through winter. This article covers the final yield results, treatment findings and an indicative economic analysis for the site. Full technical results, including establishment data, biomass measurements and nitrogen fixation analysis, are in our November pre-harvest update.

Yield

The yield monitor recorded a whole-paddock average of 2.34 t/ha from 38.6 ha harvested, with a total of 90.4 t. Jim observed yields of 3.5 to 4.0 t/ha in the best-drained sections during harvest, consistent with what he saw driving the header. In the trial strips measured through the season, core zones away from the worst waterlogging averaged 2.19 to 2.42 t/ha depending on treatment, while outer zones affected by prolonged saturation sat substantially lower. Waterlogging ultimately affected around 10 to 16 per cent of the paddock area, and its influence on the whole-paddock average is significant. On better-drained country the crop performed commercially well, and the site went on to win the GGA Crop-etition for yield, a yield competition run by the Grower Group Alliance as part of the project.

Treatment results

The trial compared three treatments of Captain desi chickpeas: a control (100 kg/ha seed, 3.5 kg/ha Nodulator), a double inoculant treatment (100 kg/ha seed, 7 kg/ha Nodulator), and an increased seeding rate (130 kg/ha seed, 3.5 kg/ha Nodulator).

The increased seeding rate treatment produced consistently higher results across plant density, early and peak biomass, nitrogen fixation and yield. Peak biomass was significantly higher than the control, and that advantage carried through to the yield data from the measured strips. The additional seed cost was $28.50/ha. In a season where canopy recovery after the reseeding event mattered, the higher plant density appears to have supported more consistent crop development through to harvest.

The inoculant result is worth reading carefully. Standard rates achieved near-complete nitrogen fixation across all treatments, with %Ndfa (percentage of Nitrogen derived from the atmosphere) values at or above 90 per cent, meaning the crop was sourcing almost all of its nitrogen from atmospheric fixation rather than drawing on soil reserves. Doubling the inoculant rate did not improve fixation efficiency. However, the double inoculant treatment showed a small positive trend in biomass and yield relative to the control, and at an additional cost of only $24.50/ha, the project team considers this a potentially cost-effective option if the response proves consistent across seasons. We would be interested to hear from growers who have observed a similar biomass or yield response to higher inoculant rates in their own paddocks.

Economics

An indicative partial budget using variable input costs supplied by the host farmer shows a positive margin over variable inputs across all treatments. At a mid-range desi chickpea price of $700/t, core-zone margins over variable inputs ranged from approximately $1,190/ha for the control to $1,320/ha for the increased seeding rate treatment. Whole-paddock margins were lower, reflecting the waterlogging penalty on outer zones. These figures cover seed, seed treatments, fertiliser and the in-crop chemical program only, and exclude operations including seeding, spraying passes, harvest, freight and levies, which would typically add $250 to $350/ha or more depending on individual farm circumstances. At the lower price scenario of $615/t, whole-strip gross income falls by around $150/ha across all treatments. Growers should work through their own cost of production before drawing on these figures for rotation decisions.

The partial budget also does not capture nitrogen carryover to following crops, which is a meaningful part of the longer-term picture. All three treatments fixed nitrogen at levels suggesting a genuine contribution to the soil system, with the increased seeding rate treatment estimated at 83 kg N/ha fixed at the time of pre-flowering sampling. Post-harvest soil analysis recorded 10 mg NO?-N/kg in the 0 to 10 cm layer, with lower but detectable levels to 60 cm depth. Most of the nitrogen benefit from this season is likely held in crop residues and root biomass rather than immediately available as mineral nitrogen, and carryover to the following cereal should not be assumed to arrive quickly or in large amounts.

For Jim’s account of the season, including the decisions made at each stage and what he would carry forward, see the case study below.