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| Cover crops provide a home for extremely beneficial "insects" and more! |
We all want "better" soil or at least to maintain the wonder-full soil we have - if we do. As crops are taken out of the soil, they remove soil, nutrients and water from the soil. So we need to continually [key word] add these and more to the soil.
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| Field radish [daikon]grown to loosen subsoil |
- to protect the soil from 'the elements'
- to build the soil through the addition of nutrients and organic matter
- to smother/kill weeds through the dense growth of the cc - and the allelopathic actions of them
- to loosen/break up the soil via deep rooted cc's,
- fight erosion
- maintain moisture
- radiation protection
- prevent leaching and volatilization of nutrients
- scavenge nutrients [especially N, P]
- carbon sequestation/fight the climate emergency
- provide home for predatory insects
- provide pollination for bees, butterflies, others
- fight pests/diseases
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| Fall rye planted in rows of Rau Ram |
The grower needs to determine which 'actions' are the most needed. Some farmers, like local organic grain producer Ray Halma cover all bases by planting mixes - consisting of 14 different plant seeds. I am also experimenting with General Seed Company's Nitro Winter Cocktail . Their website is also a wealth of information of any cover crop your heart and soil! may dream of.
A few examples for growing in the Northeast include, but not limited to:
N source: red clover, hairy vetch, berseem, sweet clover, alfalfa, peas
Soil builder: rye grass, sweet clover, sorghum-sudan grass, rye
Erosion fighter: rye, rye grass, white clover, oats
Subsoil loosener: sorghum-sudan grass, field radish [daikon], sweet clover, alfalfa
Weed fighter: sorghum-sudan grass, rye, ryegrass, buckwheat
Pest fighter: rye, sorghum-sudan grass. One audience member suggested that wire worm can be killed using black sesame.
More areas to consider include: the impact on the soil: we can look at subsoil impact, freeing up P & K and loosening the top soil. Looking at the soil ecology we should consider both the present condition of the following along with what we want to accomplish in the area of nematodes, disease, allelopathic effect and choking of weeds. Other important considerations include the attraction of beneficials, how well the cc's bear traffic and the length of the growing window.
The cost of seed also needs to be considered. It also should be noted that grasses produce much more organic matter than legumes do. And while grasses take up/scavenge N left over from previous crops, N is less likely to be released for a crop grown immediately after the cover crop is grown.
Mixing grasses with legume cc's in your cropping systems helps alleviate the N-immobilization effect. This can lead to more dry organic matter and erosion control due the different growth habits of the species.
For more information, see the classic Canadian Organic Growers "Organic Field Crop Handbook". The Organic Science Cluster work is also a valuable resource.
For a totally different and, in some ways, complementary approach, Carolyn Merchant notes in The Death Of Nature that Renaissance behaviour treated nature as a "person-writ-large". And American-Indian tribes, like the Columbia Basin Tribes opposed the Europeans attitudes in the mid-1800s [prevalent today]. Smohalla [p.28] is quoted as saying:
You ask me to plow the ground! Shall I take a knife and tear my mother's breast? Then when I die she will not take me to her bosom to rest.
You ask me to dig for stone! Shall I dig under her skin for her bones? Then when I die I cannot enter her body to be born again.
You ask me to cut grass and make hay and sell it, and be rich like white men! But how dare I cut off my mother's hair?
