Weed Population Dynamics in Four Year Conservation (CA) and Conventional (CN) Agriculture Plots in Southern Maize belt of Ethiopia

Abstract

CA methods have become increasingly popular in world due to increasing fuel cost and environmental concern. But, the sustainability of CA systems depends on the development of economical and effective weed management systems. Weed scoring was conducted on plots of conventional (CN) and conservation agriculture (CA) during the main cropping season of 2012 and 2015 in Sidama zone (Loka abya, Boricha and Awassa) with an objective of characterizing weed population dynamics in the permanent plots of maize based production systems. From each location four samples were taken using a 0.5mx 0.5m (0.25m²) quadrant. A total of 27 weed species identified in the base year became 28 weed species in the fourth year. After four years, weeds species composition, frequency, abundance and dominancy were analyzed. There was a shift in weed population from time to time and from location to location.  Quantitatively, the broadleaf weeds were found to be the most abundant family under CA systems suggesting that weed management practices should focus more on broad-leaved weeds under CA. conversely, both grass, sedge and broadleaved weeds were common in CN. The findings of this assessment could also provide important information about weed density under CA and CN systems to design site specific weed management strategies for the future as well as to assess weed dynamics under CA agriculture system. Academia, research, development organizations and policy makers shall consider annual weed surveillance to harness newly emerging weed species.

Keywords: CA (conservation agriculture), CN (conventional agriculture), weeds species, frequency, abundance, dominance