To investigate the effect of the sowing treatment on weed populations and crop performance on two contrasting soil types (a dune sand and a heavier clay loam swale).

• In a non-wetting sand, sowing on-row allowed seedlings to germinate in a wetter soil, with increased competitiveness against weed and disease pressures resulting in significant advantages in crop establishment and biomass production.
• Sowing on-row in sands or loam that did not express non-wetting did not capture the same level of benefits.
• Sowing crops on or very near last year’s crop row greatly suppressed grass weed populations and reduced brome grass seed set by over 70% compared to inter-row seeding.
• Early sowing in the last week of April instead of the third week of May helped to overcome the dry spring conditions and resulted in yield benefits of 28% at Loxton and up to 13% at Karoonda.
• When sowing crops on last year’s row, the potential for higher stubble borne pathogen (Take-All and Fusarium) inoculum and a greater likelihood of N tie-up after opening rains needs to be considered. However, impacts on rhizoctonia disease depend upon inherent biological fertility of soil.