I am sowing vetch seeds under my fruit trees to substitute for nitrogen fertilization. To get the full benefits, should I burry it once the vetch flowers?
When I grew buckwheat as a cover/green manure I would cut it just before flowering. Your question got me thinking about the timing for cutting and incorporating a perennial cover. I found this very comprehensive article on hairy vetch (Vicia villosa): http://extension.oregonstate.edu/catalog/html/em/em8699/#anchor553406 The author writes "Hairy vetch tolerates close mowing before flowering and high mowing during flowering. Close mowing during peak flowering may kill it." Good luck with your project.
Sounds like you might have experience with perennial legumeous cover crops. What would be the advantage of hairy vetch be over a lower growing clover, maybe one that could tolerate the shade under fruit trees.
Letting it mature then burrying it in the soil...slightly after it flowers is the trick. It rots/decomposes pretty quickly once burried.
This may sound naive, but must a legumeous cover crop be dead and decomposed before the nitrogen in its nodgules be utilized by another plant?
Garden Lover:""Letting it mature then burrying it in the soil...slightly after it flowers is the trick. It rots/decomposes pretty quickly once burried."" Most fruit trees have feeder roots near the soil surface. I worry about damaging them too much. Mowing and leaving as mulch is more effective here. BrianQ: ""This may sound naive, but must a leguminous cover crop be dead and decomposed before the nitrogen in its nodules be utilized by another plant?"" The degree and time of nitrogen release depends on the leguminous species planted.
Good idea in principle, but use a local native species of vetch, such as Vicia americana or V. caroliniana. I remember reading somewhere that some of the European vetches (such as Vicia villosa cited above) can be invasive weeds in parts of Canada.
Using a perennial crop such as clover is recommended for orchards and vineyards as it does release some nitrogen without tilling. Mowing and leaving the clippings as mulch is what we do.
Here is some information regarding Hairy Vetch (V. villosa) AKA Winter Vetch from WSU http://www.spokane-county.wsu.edu/Spokane/eastside/Weed_Information/weed_text/Hairy%20Vetch.pdf
