Speaker
Description
Legume-based mixed cropping systems play a crucial role in maintaining crop productivity while reducing reliance on inorganic nitrogen inputs and enhancing resilience under climate change.
Our research provides valuable insights into the long-term economic and ecological implications of adopting specific legume-based crop rotation systems, thus empowering growers to make informed decisions and facilitating widespread adoption.
The study used APSIM simulations to evaluate four distinct crop rotation systems: Canola-wheat (R1), Lucerne-lucerne-lucerne-canola-wheat (R2), Fababean-canola-wheat-barley-fababean-wheat (R3), and Fababean-barley-oat-canola-lupin-wheat (R4), considering varying nitrogen levels (0, 50, 100, 150, and 200 kgN/ha) across different climate scenarios covering historical (1984-2024) and future projections under RCP2.6, RCP4.5, and RCP8.5 (2025-2085) in four contrasting locations (Boorowa, Cootamundra, Condobolin, and Ardlethan) in NSW.
The study revealed notable differences in soil organic carbon increase (R2>R4>R3>R1) regardless of nitrogen fertilizer rates, with diminishing differences among crop rotations as nitrogen level increased. Considering wheat as a benchmark, the highest yields were observed in R1 and R3 (R1>R3) compared to R2 and R4 but yield variability increased. Moreover, the study highlights a relatively greater yield response to nitrogen rates in R1 and R3 (R1>R3). Therefore, integrating legumes such as lucerne, fababean and lupin significantly enhanced soil organic carbon levels while maintaining crop yields, suggesting the potential to achieve optimal yields with reduced fertiliser nitrogen input.
This research highlighted the value of legume-based crop rotations to improved productivity, resource-use-efficiency, and resilience of agricultural systems and offers practical insights for sustainable agricultural practices in southeastern Australia.
| Keywords | cropping systems, ecology, economics, legumes, long-term |
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