fixed nitrogen (N) from legume cover crops. Winter annual cover
crops planted after a cash crop can scavenge nutrients and reduce
nitrate leaching by up to 80% (Dabney et al., 2001; Staver and
Brinsfield, 1998).
However, cover crops are typically incorporated into the soil
using tillage before planting the following cash crop, thereby
leaving soil vulnerable to erosion during the growing season
(Magdoff and van Es, 2009). A non-tillage method for terminating
cover crops in organic systems is rolling them
flat with a roller-
crimper during a particular stage of growth. Cover crops
commonly used in this system are cereal rye (Secale cereale L.)
and hairy vetch (Vicia villosa Roth), which can be effectively killed
when rolled at anthesis for cereal rye (Ashford and Reeves, 2003)