Weed management systems and other factors affecting the earthworm population in a banana plantation

The effects of chemical and manual weed management on the abundance of earthworms and composition of earthworm populations in a banana plantation were studied in a long term field experiment. Earthworm populations were monitored in plots receiving either a cyclical course of two applications of paraquat (480 mL ha−1) at monthly intervals followed by one of glyphosate (1680 mL ha−1) or manual weeding using slashing, mechanical cutting and scraping. There were no significant differences in earthworm counts between manual and chemical plots both in areas with 15% (15° inclination) site (F = 0.48, P = 0.49) and 25% (25° inclination) site (F = 0.44, P = 0.51) during the 2-year period. Instead, variation in earthworm counts could be attributed to differences in rainfall, organic matter, organic mulch and soil cover.