Effect of cultivation methods on weed seed distribution and seedling emergence

Abstract

The influence of four cultivation treatments viz ploughing rotary hoeing power harrowing and no soil disturbance on the distribution of weed seeds in the soil profile was investigated in a field trial Weed seeds were counted by dry sieving soil samples collected from 05 510 1015 and 1520 cm depths The density and species of weeds that emerged in field plots were also recorded at threeweekly intervals Samples from undisturbed plots showed a linear decline with depth Ploughing was the only treatment that caused a significant shift of seeds to the deeper profile Ploughed plots had significantly fewer weed seedlings than other treatments due to lower numbers of both summer grasses and broadleaf weeds Undisturbed plots contained significantly fewer broadleaf species and weed emergence was delayed Implications of these results for seedbank sampling methodology and weed management strategies are discussed