The effects of soil tillage techniques on weed flora in high input barley systems in northern Spain

In barley cropping systems of northern Spain, agronomic practices and weather conditions are key components of weed control efficacy. We compared the short-term effects of conventional tillage (CT) with minimum tillage (MT) and zero-tillage (ZT), in barley monoculture and barley rotation systems. Weed density and weed species number were measured at tillering and flowering barley stages. We found that tillage system can influence weed density and weed species establishment due to, in part, the available light for weed seeds. The results obtained led us to believe that MT system facilitate the prevalence of the grass weed Bromus diandrus Roth (50.37%) and the annuals dicots Galium aparine (L.) and Lithospermun arvense (L.) abundant were high in MT system too, 43.71% and 43.97% respectively. The germination of these species showed high dependence of light availability. We saw that barley-monoculture plots had a great infestation of Bromus (71.29%) and barley-rotated plots presented more infestation of Galium and Lithospermun (74.36% and 84.4%). After herbicide application, weed infestation in conservation systems was reduced in barley-rotated plots compared to barley-monoculture. If conservation systems avoided the presence of dominant weeds, the weight of each weed species was balanced within competitive relationships of the cropping systems. Our results confirmed that MT and ZT systems favour different weed species emergences in barley-rotated plots. The combination of MT and barley rotated cropping system resulted in terms of greater weed diversity and lower total weed density.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author