Weeds and the soil environment - Ecological Management of Agricultural Weeds - page 231

Figure 5.6 Fate ofwinter wheat seeds sown into conventionally tilled standing
maize on 18 and 20 September 1990,and evaluated on 9 October 1990.Seeds
were either placed on the soil surface,placed on the surface but protected with
cloth covered screen to exclude mammals and surface dwelling
macroinvertebrates,or planted at 2 cm depth.Partial exclosure treatments (data
not shown) indicated that slugs and earthworms were the principal seed
predators.(C.L.Mohler,unpublished data.)
by tillage several weeks before planting cash, fodder, and food crops. When
used as mulches, cover crops often are killed with non-residual herbicides
such as glyphosate or paraquat shortly before planting the next crop.
Alternatively, some cover crops can be killed by mowing after they have
reached a certain stage of maturity (Table 5.1). Creamer et al . (1995) developed
an undercutter that killed winter rye, hairy vetch, and crimson clover cover
crops by severing roots with minimal soil disturbance. Ideally, a mulch crop
would grow during the fallow season and then die back naturally as the main