This study was conducted to investigate how different mulching types affect the occurrence and distribution of weeds in 35 maize and soybean fields in Jeonnam province, and to find out the relationship between population variation within the same species and dominant levels of weeds based on important values. In June and August of 2020, we determined that maize fields had 27 and 21 different weed species, respectively. In June, August, and September of 2020, we found 28, 33, and 31 different weed species in soybean fields, respectively. In maize and soybean fields, the rankings of the top six dominant species differed slightly by survey period and crop, but the kinds of weed species were similar. The ten most dominant species at all survey periods in both maize and soybean was Digitaria ciliaris>Acalypha australis>Eclipta prostrata>Chenopodium album>Amaranthus lividus>Abutilon theophrasti>Cyperus microiria>Echinochloa crus-galli>Bidens frondosa>Mollugo verticillata. Weed occurrence in maize fields was not significantly different regardless of mulching type. However, in soybean fields in June, August, and September, 28, 28 and 31 different species of weeds were detected in areas using non-mulching methods and 12, 18, and 20 species were detected in areas using black vinyl mulching methods, respectively. In both maize and soybean fields, the order of rankings of the top ten dominant species by mulching types was different, but the kinds of species were similar. In maize and soybean fields, it was determined that the variation between minimum and maximum shoot fresh weight in weeds of the same species was greater in June than in August and September. In addition, most of the weeds with the greatest variation between minimum and maximum shoot fresh weight in both maize and soybean fields were the same weeds that were most dominant in terms of important values, although the order of ranking varied slightly. Thus, weeds with the greatest shoot fresh weight variation are likely to become dominant weeds due to factors such as climate change.
Figures & Tables
Fig. 1. Survey sites of soybean (A) and maize (B) fields in Jeonnam province.