UQ study says crop breeding could boost next-season yields

Researchers at The University of Queensland say breeding crops for farming systems, not just standalone yield, could lift subsequent wheat harvests and reduce fertilizer costs. In a mungbean-wheat trial in southern Queensland, some mungbean lines raised the next wheat crop by as much as 45% while others cut it in half.

Why it matters: - Breeding crops for how they affect the next crop could help farmers cut fertilizer costs and improve whole-rotation productivity. - The approach shifts crop breeding from single-crop yield to system-level performance. - UQ researchers say the method could reveal genetic potential that conventional breeding has overlooked.

What happened: - Researchers at The University of Queensland published a study arguing that crop breeding should target farming systems rather than yield alone. - The team tested the idea in a mungbean-wheat rotation in southern Queensland. - More than 300 genetically diverse mungbean types were grown at a research station, and the same wheat variety was then planted across all plots. - The research was published in Plant Communications and Nature Genetics.

The details: - The experiment found wheat yields varied by up to 1 tonne per hectare depending on the preceding mungbean variety. - Some mungbean lines lifted following wheat yields by 45%, while others reduced them by half. - The research team said the results show the effect is real and heritable. - Professor Lee Hickey said the team identified specific regions of the mungbean genome linked to performance of the following wheat crop. - Hickey said some genetic regions may improve one crop's yield while leaving fewer soil resources for the next crop. - The team simulated selection applied equally to mungbean yield and subsequent wheat yield. - That simulation suggested gains in both crops, with lower input requirements. - The researchers said the same logic could apply to other rotations, including canola-wheat and chickpea-barley.

Between the lines: - The findings suggest crop genetics can influence rotation benefits, not just farm management choices. - If breeding programs can select for legacy effects, farmers may be able to improve total system returns without relying only on more fertilizer or other inputs. - Dr Millicent Smith said the biology behind the effect is still unclear, so the work remains an early step rather than a finished breeding tool. - The research also points to a broader shift in plant breeding as drones, genomics, crop models and computing make large-scale systems testing more practical.

What's next: - The team plans broader testing to understand what drives the legacy effect. - Smith said the next step is to uncover the biology behind the results and that will require a community effort. - The researchers will also need to test whether the same breeding strategy works across more crops and environments.

The bottom line: - UQ's work suggests crop breeding could move from maximizing one harvest to maximizing the whole rotation, which could change how farmers and breeders think about productivity.