Weed treatments consisted of Bromus tectorum (downy brome), a combination of Thlaspi arvense(field pennycress) and Descurainia sophia(flixweed), and a weed-free control. Treatments were organized in a split-split-plot design with four replications. Main plots were application timing-tillage intensity, sub-plots were N source,and sub-sub-plots were weed species. Sub-sub-plot size was 2m wide x 5m long