-
webmaster
- Site Admin
- Posts: 9478
- Joined: Sun Feb 08, 2004 12:59 pm
- Location: Amherst, MA USDA Zone 5a
Rotation in an Organic Garden
What kinds of plants do you consider mandatory for rotation in a garden? Why rotate? What does it do for the soil, etc?
-
opabinia51
- Super Green Thumb
- Posts: 4659
- Joined: Thu Oct 21, 2004 5:58 pm
- Location: Victoria, BC
Wow Roger, that's a huge quesiton.
Well, you want to have soil builders and nitrogen fixers.
Soil builders are plants from which you annually cut down and leave the cuttings on the soil that macro and micro-organisms break down into more soil. I'm thinking, Rye, oats, wheat, chickweed(you can eat this one as well), dandelion, daikon (improves clay soil) and so on....
Nitrogen fixers generally consist of legumes but, non legumes (ie. plants from a different family) also fix nitrogen. Here are some Nitrogen fixers, that you can plant in the rotation: Peas, beans, clover, and hairy vetch.
Why Rotate:
Well firstly say for instance that you plant corn or tomatoes in the same spot every year. These are both heavy feeders and all of the nutrients in that area will be used up very shortly. Rotation, builds the nutrients that were lost back up.
Second, if a plant is continually grown in the same area, any pathogen that feeds on the plant will reside in that area and reak havoc on tha the plants grown. Rotation, dissemanates the pathogens by taking away their food source. This allows, nature to come in with more beneficials that will eat up the pathogens and keep them in check. If you plant the same annual over and over (and use pesticides) you are actually artificially selecting for pathogens.
Take a look at a forest and it's evolution from grassland to forest. This starts with founder species such as grasses, next you get deciduous trees springing up and shading out the grasses and other founder species (which also build up the soil such that the deciduous trees can get started) and finally, conifers come in and eventually overtake the conifers. (The deciduous trees, through the decompisition of their leaves have built up the soil even more for the conifers).
We want to try and mimic this in our gardens. Obviously we don't want to build up a coniferous forest but, we want to keep the nutrients and plant sequence flowing such that pathogens don't build up. With continually added organic matter, the soil will consist of an equal balance of pathogens to beneficials (and one could not survive without the other).
What does it do for the soil:
In short, it makes the soil. One more thing about Nitrogen fixers, when they are mowed, the roots (that can extend up to 15 feet into the soil slough off and add Nitrogen (from the N fixing bacteria that associate on and in nodules on the roots ) to the soil.
Of course, crop rotation is important but, what is equally important is that you don't monocrop. The trinity is a great way of growing corn, feeding the soil and keeping weeds down. Corn, peas/beans, squash.
Well, you want to have soil builders and nitrogen fixers.
Soil builders are plants from which you annually cut down and leave the cuttings on the soil that macro and micro-organisms break down into more soil. I'm thinking, Rye, oats, wheat, chickweed(you can eat this one as well), dandelion, daikon (improves clay soil) and so on....
Nitrogen fixers generally consist of legumes but, non legumes (ie. plants from a different family) also fix nitrogen. Here are some Nitrogen fixers, that you can plant in the rotation: Peas, beans, clover, and hairy vetch.
Why Rotate:
Well firstly say for instance that you plant corn or tomatoes in the same spot every year. These are both heavy feeders and all of the nutrients in that area will be used up very shortly. Rotation, builds the nutrients that were lost back up.
Second, if a plant is continually grown in the same area, any pathogen that feeds on the plant will reside in that area and reak havoc on tha the plants grown. Rotation, dissemanates the pathogens by taking away their food source. This allows, nature to come in with more beneficials that will eat up the pathogens and keep them in check. If you plant the same annual over and over (and use pesticides) you are actually artificially selecting for pathogens.
Take a look at a forest and it's evolution from grassland to forest. This starts with founder species such as grasses, next you get deciduous trees springing up and shading out the grasses and other founder species (which also build up the soil such that the deciduous trees can get started) and finally, conifers come in and eventually overtake the conifers. (The deciduous trees, through the decompisition of their leaves have built up the soil even more for the conifers).
We want to try and mimic this in our gardens. Obviously we don't want to build up a coniferous forest but, we want to keep the nutrients and plant sequence flowing such that pathogens don't build up. With continually added organic matter, the soil will consist of an equal balance of pathogens to beneficials (and one could not survive without the other).
What does it do for the soil:
In short, it makes the soil. One more thing about Nitrogen fixers, when they are mowed, the roots (that can extend up to 15 feet into the soil slough off and add Nitrogen (from the N fixing bacteria that associate on and in nodules on the roots ) to the soil.
Of course, crop rotation is important but, what is equally important is that you don't monocrop. The trinity is a great way of growing corn, feeding the soil and keeping weeds down. Corn, peas/beans, squash.