Weed control ability in sweet maize of single sown legume cover crops compared to their mixtures

Abstract

To achieve efficient weed control through cover cropping, the plant species chosen is very important. Growing different legume cover crop (CC) species single and in mixtures with grass may increase the number of provided ecosystem services, including reliable suppression of weeds. We conducted an experiment using randomized complete block design with four replications in 2014/15 - 2015/16 growing seasons, at the Experimental Field of Maize Research Institute in Zemun Polje (Serbia). Single cover crops were considered as the main factor (common vetch and field pea), mixtures common vetch and field pea with winter oats and traditional variant, without coverage on biomass. Green biomass of the cover crops was incorporated in the soil, and treatments with favorable establishment and above-average biomass yields tended to suppress weeds by showing lower weed dry matter and weed numbers. The weediness of sweet maize was much higher in the second year of investigation. The number of weed species, fresh and dry biomass of weeds were the least in the variants with mixtures, while the number of plants per specieswas the lowest in the single cover crops. So, mixtures were not as effective as legume single sown CCs, species combinations increased resilience against adverse weather conditions, an advantage to achieving efficient weed control over a long-term period. The statistically significant difference in the fresh biomass of weeds obtained in the control variant (540.46 and 385.88 g) was especially pronounced compared to the variants with single cover crops (391.63 and 486.53 g) and their mixtures (260.00 and 250.78 g), indicating a higher proportion of perennial weed species.