Effects of dryland summer cover crops and a weedy fallow on soil water, disease levels, wheat growth and grain yield in a Mediterranean-type environment

Numerous studies have reported wide-ranging benefits of cultivating cover crops during the typical fallow period in temperate cropping systems. However, data on impacts summer water-limited, Mediterranean-type climates, is lacking. A 3-year field experiment was conducted near town Northam wheat-belt Western Australia to test hypothesis that inclusion would increase ground cover, water storage and grain yield subsequent wheat crops. White French millet ( Panicum miliaceum ) cowpea Vigna unguiculata a weedy were compared chemical over period. Autumn groundcover 10–30% higher when weeds left uncontrolled treatment. Dry-sown late established (February) failed groundcover, whereas demonstrated small (~9–10%) one season, biomass approached 1 t ha −1 . Cover growing had no significant effect total plant available (0–50 cm depth) prior sowing any season. there less readily soil N crop (less 10–30 kg 50 treatments second crop. Despite some effects cowpeas Gaeumannomyces graminis var tritici (take-all) Didymella pinodes (causing black pea spot), disease levels low thought pose little risk following winter Wheat yields not significantly different between treatments, other than after 2015 due emergence count. Grain protein screenings generally affected by treatment year, except for year. Given limited disease, it possible may be able integrated with cereal rotations without reductions In light current usage, issues around herbicide residues herbicide-resistant weeds, worthwhile revisiting need fallow, particularly rainfall areas.