Description:
The benefits and limitations of pulses
Pulse crops, such as chickpeas and lentils, have traditionally been encouraged as a disease break for cereal-dominated rotations, with their ability to fix nitrogen being a welcome bonus.
The recent increase in demand for pulses has led to higher prices, and in some areas, pulse crops have taken over as the central pillar of crop rotation.
Previous projects by the Grains Research and Development Corporation (GRDC) estimated there was a yield gap of about 40 per cent from pulses, and there was room to improve how a limited amount of available water is used by chickpeas, lentils and other pulses.
The National Pulse Agronomy project (NaPA) project aims to quantify how yield formation in these indeterminate crops is limited by water stress and temperature and identify how crop timing, including sowing date and the length of reproductive stage, can be used to manage or avoid losses.
The project will investigate the efficiency of nitrogen fixation in stressed plants and evaluate its role in achieving the crop water-limited yield potential.
The aim is to deliver appropriate variety by management packages that provide information about different profit/risk scenarios based on the combination of experimental data and crop modelling.
The project involves a national team from various organisations, led by CSIRO, with the Department of Primary Industries and Regional Development Western Australia (DPIRD) conducting trials in WA.
Each organisation will conduct similar experiments within their local environments using similar protocols and the results will be analysed nationally.
2022 trial details and results
In 2022, WA had one satellite chickpea trial at Deepdale, near Geraldton, which featured four times of sowing and eight varieties.
Across multiple states, including WA, 2022 trials suffered disease and flooding issues due to higher than average rainfall.
Despite multiple fungicide applications at Deepdale, this rainfall contributed to botrytis grey mould and sclerotinia developing in some varieties of April sown chickpeas, which is thought to have impacted yield.
However, based on previous time of sowing trials conducted by DPIRD there has rarely been a benefit to sowing in April and in this trial, the varieties sown in May witnessed much less disease pressure.
WA adapted variety, CBA Captain sown on May 10 produced the maximum yield results in the trial, of over 2.9 tonnes per hectare, while most other lines produced their highest yields when sown on May 27.
Across all varieties, average yield for April 12 was 1.6t/ha, April 26 was 1.8t/ha, May 10 was 2.4t/ha and May 27 was 2.5t/ha.
This reinforces the current thinking that there is little benefit to sowing chickpeas earlier than May in WA.
Plans for the 2023 season
There is one detailed site at Northam planned for 2023, with two times of sowing (mid-May and early-June), four varieties that have different water use patterns (including Captain and Striker which are the best yielders in WA), and two water treatments.
Half of the plots will be rain fed and half will have irrigation applied when there are dry periods through spring.
The move to a detailed site allows DPIRD to take much more in depth measurements to gain a deeper understanding of the water use patterns of different genotypes and the critical periods for yield development.
This year, the researchers will also be looking at how water stress affects nitrogen fixation and by better understanding and optimising crop growth in each location, they can match pulse varieties with soil and climate to help growers achieve water limited yield potential, maximising their profit and yield.
Future trials and the ultimate benefit to growers
In 2024, DPIRD will have one detailed site and potentially one satellite site in the central Wheatbelt.
By the end of the project, growers and agronomists will have an improved understanding of pulse growth and development across a range of environments, enabling the matching of pulse genotypes with soil and climate to maximise yield and profit, with manageable risk in Australian cropping systems.
Funded by:
DPIRD, GRDC, CSIRO, NSW DPI, AgVic, UQ, and SARDI
Project code:
CSP2107-003RTX