About four weeks ago our local farmer, Duncan Ellis, planted out a cover crop on the fields we will be planting with vines in 2012.
I spent many weeks in the Plumpton College library reading books about cover crops and got very confused.
Essentially you plant a cover crop to protect the soil from erosion, to prevent weed growth and as a green crop to improve soil fertility, adding nutrients and improving soil structure by raising the humus level in the soil. This last point is very important to us as the soil samples we have taken indicate that, although the soil is fine for arable crops, the potassium, phosphate and magnesium levels are below the levels ideal for vines. So prior to planting our vines in spring 2012 we are trying to raise the levels of essential nutrients in the soil by direct addition of fertiliser, green waste (the council recycled stuff) and cover cropping.
I had initially planned to plant out red clover as our cover crop, however, as the soil at Rathfinny is so well draining I was advised that clover doesn’t take very well. So I then looked common vetch, Austrian peas, rye and mustard. All cover crops that have been used in organic vineyards in California.
We have settled on mustard, principally because it will take well on the soil at Rathfinny, and despite the lack of rain since planting, it has already come up well in most areas. I was advised that peas could be susceptible to some forms of nematodes and also sclerotinia crown rot. Sclerotinia is a fungal infection, which can also affect grapevine roots. In order to lessen the risk of this infection in the peas, the advice was to plant two pea crops in succession. Which is a shame because from my research peas look to be the best returner of nitrogen, and the best biomass provider. Some of the vineyards in California have had problems with common vetch, which is also a good nitrogen and biomass producer, but it became too invasive and difficult to control. So in the end, after consulting experts from Plumpton College and Ohio State University, thank you Patti, we decided on mustard. Which, when mowed and turned into the soil in early 2012, will provide a good deal of biomass, some nitrogen and will probably reseed itself after the vines are planted out.
We may plant out some crimson clover and rye grass latter this year to add further biomass. This can be turned in prior to planting in spring 2012.
Mustard, as well as being pretty good for the soil it also looks good in a vineyard.
A great blog about the use of mustard.
Our mustard is taking well… so are the nettles!