Nitrogen contributions are provided by the biological fixation of atmospheric N by bacteria residing in root nodules of legumes such as:

	Purple Vetch
	Bell Beans
	Woollypod Vetch

Cover crops are plowed under as green manures to provide N and organic matter to the soil. Cover cropping results in an average of about 60 lbs N/acre for subsequent rice crops.

Click here for data.

Cover crops also:

• Improve soil tilth by:

• increasing soil pore space
• enhancing microbial activities
• providing additional cation exchange sites for nutrients
• Reduce the energy required for tillage

Concerns, however, that may impede adoption of cover cropping include:

• The delay experienced in rice seedbed preparation

• Cover crop planting may interfere with rice harvest

Adapted from the resources available at:
   UC SAREP Cover Crop Resource Page and the
   UC Cooperative Extension Rice Project