Regarding legumes as cover crops: I have been told that the majority of the...

Asked October 1, 2014, 10:23 AM EDT

Regarding legumes as cover crops: I have been told that the majority of the nitrogen-fixing function that a legume performs happens when the plant is flowering. Is this accurate? Thanks!

Montgomery County Maryland soil improvement vegetable cover crops horticulture

2 Responses

Yes, it is right before and at flowering. A good time to turn them under is as soon as they start to flower.
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I'd like to add a comment for clarification. The N-fixing process involves the interaction of the roots and soil. Flowering does not actually cause an increase in the ability to fix nitrogen; but anything that enhances root growth (such as more leaves for photosynthesis) would increase nitrogen fixation. The plant is likely in this state just before flowering, so you might use the onset of flowering as an indicator for nitrogen fixation.