Editing Crop rotation (section)

=== Weed management ===

Integrating certain crops, especially [[cover crops]], into crop rotations is of particular value to [[weed control|weed management]]. These crops crowd out weeds through competition. In addition, the sod and compost from cover crops and green manure slows the growth of what weeds are still able to make it through the soil, giving the crops further competitive advantage. By slowing the growth and proliferation of weeds while cover crops are cultivated, farmers greatly reduce the presence of weeds for future crops, including shallow rooted and row crops, which are less resistant to weeds. Cover crops are, therefore, considered conservation crops because they protect otherwise fallow land from becoming overrun with weeds.<ref name="moncada2010">{{Cite report |author1=Moncada, Kristine  |author2=Craig Sheaffer |date= 2010 |chapter=Chapter 2 Rotation |title=Risk Management Guide for Organic Producers |publisher=[[University of Minnesota]] }}</ref>

This system has advantages over other common practices for weeds management, such as [[tillage]]. Tillage is meant to inhibit growth of weeds by overturning the soil; however, this has a countering effect of exposing weed seeds that may have gotten buried and burying valuable crop seeds. Under crop rotation, the number of viable seeds in the soil is reduced through the reduction of the weed population.

In addition to their negative impact on crop quality and yield, weeds can slow down the harvesting process. Weeds make farmers less efficient when harvesting, because weeds like bindweeds, and knotgrass, can become tangled in the equipment, resulting in a stop-and-go type of harvest.<ref>{{Cite web |url=http://potatoes.ahdb.org.uk/sites/default/files/publication_upload/Weed%20Control%20in%20Potatoes.pdf |archive-url=https://web.archive.org/web/20161019200703/http://potatoes.ahdb.org.uk/sites/default/files/publication_upload/Weed%20Control%20in%20Potatoes.pdf |archive-date=19 October 2016 |url-status=live |title=Weed Control in Potatoes |last=Davies |first=Ken |date=March 2007 |publisher=British Potato Council |access-date=1 December 2016}}</ref>