Steve,
I disagree that you don't need to rotate. Different plants require different amounts of specific nutrients, and if you keep planting the same crop on the same soil year after year, you will deplete specific nutients faster that you can replace them organically. In addition, you will never know for sure what nutrients you are depleting and by how much, unless you do a complete soil test at least once a year.
To be on the safe side, rotate what you plant to a different area of your raised beds every year, and not have to worry so much about it.

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journam Entry for Feb."

One really doesn't deplete nutrients at a different rate when growing most plants, including veggies.

This is kind of an old idea from the same period that told us using a lot of phosphorus was the way to get more blooms when all it did was tie up other nutrients and stress the plants into blooming while polluting the environment.

Most plants use the 'big three' nutrients in a 3:1:2 or 3:1:3 ratio. We know this from tissue analysis as well as soil tests done before and after a crop has been grown in it. The rate these use the secondary nutrients is also consistent enough that we don't have to worry about what nutrients a plant is taking from the soil.

The only exception I can think of would be legumes which can add N to the soil if their roots are allowed to decompose in it.

Anything can be grown after anything and organic matter will resupply everything adequately other than (in some cases) nitrogen which can be supplemented.

As long as you're seasonally amending you're grow area with compost and manure you should be fine. You should also try to get a cover crop in between you're growing seasons, especially grasses/brassicaceae which tend to be non-host crops to veggie diseases and bio-antifungals respectively.

justaguy2 ,
That's just nopt true! Corn, for instance, requires a lot of nitrogen, and will deplete the soil a lot quicker that potatoes, for instance that use a lot less nitrogen, but a lot more phosphorus. Garden plant do not use all the nutrients at the same rate. Try growing corn on the same soil, without amending it with a higher nitrogen feed that other beds, and you will get stunted, light green plants with poor production. I farmend organically for over 10 years, and I can tell you forst hand, crops do not use nutrients evenly. Ask any farmer!

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journam Entry for Feb."

That is certainly true, Ron. What I was trying to communicate is that while a plant may use more *total* nutrients than another, the ratio they use nutrients is pretty similar.

As an example, corn uses nutrients (just NPK) in a 2.5:.2:2.5 ratio, or more generically a 3-1-3 ratio.

Potatos use NPK in a 2:.2:2.5 or more generically a 2:1:3 ratio.

Because the ratios rarely deviate by much between crops we can talk about heavy feeders and light feeders, but not so much a plant that depletes N or P or K and things like that.

One could, I suppose, rotate to have a light feeder follow a heavy feeder while organic matter was being processed into the soil.

What I thought you were saying is that one plant uses all the N so you would have to plant beans which get their own N from the air or something.

I think we agree!! The purpose of rotating crops is so the soil has a chance to regain nutrient balance when certain nutrients are used up more than others. No plant, of course, uses all of any thing, and organic based nutrients take time to break down and become available for plant use, as I am sure you well know.

I think part of my perspective comes from living in the north where we only get one season per year for gardening so I don't worry about successive crops exhausting nutrients.

Grow a crop, add OM, wait until spring, add OM, grow a crop, add OM is the way it goes.

Crop rotation was originally used as a means to maintain soil fertility where you spread your manure on the field one year and raised crops in succeding years to best utilize the soil nutrients. Since different crops were raised someone noticed that this helped control plant diseases and insect pest. If you only feed your soil once every 7 years you may need to think about crop rotation, but if you but back into the soil, every year, the nutrients the crop you grew, if you maintain your soils fertility then rotating is unnecessary for soil health. In the average back yard garden rotating crops for insect pest and disease control will only be successful if you can seperate the plots by 300 feet or so.

Thats not quite true kimmsr!
If you plant corn, a very heavy nitrogrn feeder, and amend your soil that grew the corn the same as the rest of the garden, that soil would not receive sufficient nitrogen to bring it back to it's orininal content.
It replace the nutrient content used by a specific crop, you would need to do constant soil testing and and apply different amendments to every area of your garden. hardly something most gardeners would care to do. In theory what you say could work, but it's not practical for most gardeners or farms.
I, for instance, have 4 x 10 raised beds. I usually have several different veggies growing in each bed. It would be impossible to amend each area of each bed to replace the specific nutrients used. The common sense approach is to plant different veggies in each bed every year, and use good organic practices to maintain fertility. Crop rotation is a must in most garden senerios for good harvest and healthy soil!

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journam Entry for Feb."

Crop rotation is a must in most garden senerios for good harvest and healthy soil!

I also have raised beds and I do not rotate. I grow what I grow in a given bed primarily to maximize sunlight to the crops.

I *have* encountered low N issues, but that is because I don't use manure in the beds, just year old compost and it tends to not be high in N. I simply toss some soybean meal into the beds and the N problem is resolved.

If you grow the same things in the same place year after year, eventually you WILL have nutrient issues. I assume you are confirming this with regular soil tests?

You may have gotten away with it so far, but it will happen sooner or later. That is why all good farmers, and gardeners rotate their crops.

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journam Entry for Feb."

you grow the same things in the same place year after year, eventually you WILL have nutrient issues. I assume you are confirming this with regular soil tests?

Why would growing the same thing year after year result in nutrient issues if the growing soil is getting biannual additions of organic matter and as needed N additions?

If I was doing nothing to the soil and kept growing stuff I would understand that the good times would eventually end, but with a continual replenishment I just can't wrap my brain around what the problem would be. The beds in question are going on year 7.

Do I regularly have soil tests done? No, why would I? The soil tests available are for mineral based soils and I have organic based soil (vermiculite, peat and compost, mostly compost). The tests would not be even remotely accurate. I let the plants tell me if they are in need and other than N there has not been any need I can see.

Those that rigidly maintain a position of any kind have not thought out all the ramifications involved. If the health of the soil is maintained, by adding compost and other forms of organic matter, something that can be done better that way then by crop rotation, then there will be many fewer problems with insect pests and plant disease then if you rotated you plantings in the small spaces that backyard gardens do have.
I know many people that absolutely insist that the backyard garden must be rotated that have plants that are every year attacked by insect pests and plant diseases anyway, while the plants, growing in the same bed for many years here have not been so bothered.

justaguy2,
With the soil base you use, I would be very concerned about tract mineral imbalances for starters. Just adding organic matter an N is not going to correct or maintain proper levels of Phosphorus or Potash if you regularly grow crops on the same soil that are heavy feeders of those nutrients.
I also disagree that a soil test would not be accurate. It will provide an accurate reading of nutrient levels regardless of the soil base. I think you might be surprised at what a good soil test would show you about your practices.

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journal Entry for Feb."

farmersteve: I was taught crop rotation at the age of nine in a village school in England during the war. Like most things we learn at that age it has stuck, and I have seen no reason in the intervening years to change my mind. I present three reasons for rotation: disease control, mineral balance, and the need to provide nitrogen by growing legumes in rotation.

1. Disease control: the agents of disease, mostly fungi, are always present in the soil, usually in populations that aren't large enough to cause problems. They are specialists; when you grow their favourite food, their population will increase dramatically, let's say one hundred fold. If you grow the same crop in the same place for a second year, the pathogen population will again grow a hundred fold, so it's now 10,000 times larger than the original population -- in the assumption used -- and in a position to do damage. Whereas, if you rotate the crop, the pathogen poulation will eventually fall back to its orginal level. Having said that, I know a fellow who grows tomatoes successfully in the same place every year; but do you feel lucky?

2. Mineral balance: all vegetable species require the same essential minerals, but not in the same proportions. My favourite example of this is spinach, which is a heavy boron user, so that if it were grown in the same place year after year the boron level would decline and the soil minerals would become seriously out of balance. By rotating, you allow the natural processes of release of minerals from the "rock" content of the soil to catch up with the disparate mineral needs of your crops.

3. Nitrogen from legumes: organic growers don't get their nitrogen out of bags or bottles, they often don't have access to manure, and they are unable to make enough compost to provide for all their nitrogen needs. Legumes in rotation is the answer, not only peas and beans, but also leguminous cover crops.

I hope this gives you a useful basis for a practice that really ought to be second nature for any gardener or farmer. Regards, Peter.

Amen Peter, Amen!

Ron
The Garden Guy
http://www.TheGardenGuy.org
"New Article & Journal Entry for Feb."

OK guys, this has been most entertaining, I'm aware of the other thread the OP is talking about. I recall the advice given was to plant the tomatoes at the south end of her little plot next year...by all means mix things up a bit if that would make her feel better.

when I hear about people wanting to do crop rotation in little gardens I think they mean what I do. I have 15,000 sq feet in the works. when I rotate a section, that piece is only growing green manure for a whole year. It's getting horse manure, compost material, leaves/grass etc it's out of production for 12 months.

for these little guys to do rotation properly they wouldn't be growing much at all because half their garden would be out of service for a season. That's why she was advised not to stress over it.

Steve, you said "It seems to me that the issues with bugs and diseases are quite simple, that these problems can easily travel the few feet I have moved their host. However for nutrient levels, it would still seem to be advantageous to rotate one bed to the next or flip flop ends and so on through a multi-year cycle" I think you're on track with that thought...take it out for a season, let it rest.

All,
I appreciate all of the garden input (there's an organic double entendre for you). I think that rotating seems the best option for me primarily because that is the best way for me to get a cover crop into different areas each year.

As was alluded to by justaguy, I think, I am dealing with a long season with successive planting and some crops grown right through the winter. If it were not for the plan (and I want to emphasize the word plan and not execution) of rotation, then I would only be able to plant cover crops on the same areas year after year. If I ever stop major tweaking to the garden layout and contents of vegetables, then I may be able to execute a plan to rotate the cover crops effectively.

As it is, I make a new plan for rotation each and every year with my new plan for what I will be growing for the next several years. Then the next year I go and change it all up again and out with the old plan and in with the new...

Some day I may have enough space to hold an area for green manure only (don't tell my wife, but that's the long term plan).

Thank you all,

Steve

bloosquall: I'm unclear why you think that rotation "done properly" means leaving any land out of production at all; what have you in mind? My view is that roots-in-the-ground-all-year-round is one way to keep pumping carbon out of the air into the ground and so keep the microbes well fed and active. And those roots might as well be food crop roots.

Also I can't quite grasp why you think scale realates at all to rotatablity (to coin a word). If you have a garden measuring 2 feet by 2 feet you can have 4 one-foot plots rotating straightforwardly. Please explain your thinking, I just can't see what's in your mind, and (despite my advanced age) I am anxious to keep learning. Regards, Peter.

Good evening Peter,

I believe taking the ground that was used for growing corn, spuds, beans, garlic etc out of production for a year is correct. I did not say leave it bare, I may have used the wrong words when saying "let it rest". IMO it's not advisable to grow a plant that is going to take more from the soil than it's putting back into it.

I wrote "when I rotate a section, that piece is only growing green manure for a whole year. It's getting horse manure, compost material, leaves/grass etc it's out of production for 12 months". In the off year for a section if I'm on the ball I can have a vetch crop and a couple green pea stands before it's time to plant in the fall. all that lush green matter and N gets worked into the ground...More goes in than was taken out.

"I can't quite grasp why you think scale relates at all to rotatablity" Nothing really, My answer to that woman who was asking about it [Planning new BIG garden! Help with crop rotation plans] I thought about what the average back yard gardener does and gave my opinion, she probably isn't doing any intensive planting of crops that are going to zap her soil so advising to put her tomatoes at the south end and mix things up year to year was logical. She made her plot bigger so she could grow more stuff, she doesn't want to cut that in half every year.

I'm aware that some of my opinions and tactics aren't real popular on here, but it's nice to hear a different point of view, let the guy who asked the question decide what's best for him/her.

I'm a small scale farmer rather than a gardener. I'm pretty serious about what I grow and the condition of the soil since I'm 100% organic. I have read about big farmers being 100% organic, they do this very same thing but on a huge scale with big machines.

So, I do try to have roots in the ground all the time..but half the time those plants are there to get disced in. ;-)

So if you can't rotate because of sun issues, then do you just not garden?

I read Stacy's post again, I saw "intensive planting" I understand what she's talking about since I'm also in the north where the growing season is much shorter. My advice is still to plant in different locations is she doesn't want to cut her ground in half.

I don't understand "sun issues" ???

Steve and Shebear, I don't know anything about your season down south. I would guess that ya'll could get couple cover crops in and still have time to have a regular vegi planting before winter.

bloosquall,
A couple of examples of my planting for my zone are:

1) In one area I started peas a few weeks ago (late Jan/first of Feb). After the peas are done in April or so, I will put some cantaloupe in that same area. When those have run their course in late summer or early fall, I plan to put in some Brussels sprouts and kale. These may last me through the winter.

2) In another bed I would have (if last fall was not so busy) garlic and shallots in the ground through the winter for 1/3 of the bed and crimson clover in the other 2/3. In early April the clover will be cut down and turned in to the top few inches of soil in prep for the tomatoes to go in mid to late April. When the garlic and shallots are harvested from the other end (late May or early June), the zucchini and crook neck squash will go in.

In other sections, I start cabbage, lettuce, chard, beets, and carrots in early winter that are all followed by other things when they are done. So, as you can see, without expanding the garden (a constant discussion and struggle with my wife) I have only some sections of the garden where I can get cover crops put in long enough for them to mature. This section, it seems to me, is the most important to rotate to new parts of the garden. Sometimes I can get catch crops in; sometimes they're radishes for eating and sometimes cover crops for the soil.

All in all the rotations are challenging for me because some sections of the garden flow into non-traditional veggie seasons and cover crops do not have the opportunity before it is time for the next growing season. I do feel lucky that I can get something to eat out of the garden pretty much year round most years, but I am struggling to make sure that the soil has what it needs to keep feeding me and the family.

Steve

Steve,

Sounds like you have a great plan. Thank for explaining how things work in the south, I have no idea. I'll plant my first green pea crop in late april..maybe. Look up Justaguy and Dchall for ideas on what meals do what if you don't know. I saw that soybean meal is a nitro source. Alfalfa pellets from a feed store are also good I've heard. I do know much about them. I use a lot of horse manure...adds great texture

I have access to a pile of rotting alfalfa hay bales..pondering getting a few and spreading them out, let them decompose on my ground and it's free.

Send the wife to her sisters for a few days, that'll give you enought time make a third bed hahaha. It's easier to ask for forgiveness than permission anyway.

My wife and kids are heading "home" to California for 3 weeks in May and June. They may be surprised when they get back.

I think there is a big difference between what's best and what's a compromise. I don't think anyone is saying don't garden if you can't do it perfectly, but we're all saying that the less perfect your practices, the more likely you are to have problems, and the less perfect your results.

When I had a 100 square foot area to garden at the community garden in a three month growing season, I sure wasn't going to leave anything to "rest" every other year, or even once every three years.

The advantage of rotating, as I learned, wasn't so much about fertility, because if you have to you can amend the soil to replenish what was used by whatever you grew. It was to minimize the disease potential for soil-borne problems. A minimum of three years rotation (one year on, two years off) WITH DIFFERENT CROPS TAKING TURNS ON THE TWO "OFF" YEARS, was how I learned. So, one year brassicas, followed by a year of corn, and then a year of whatever else, maybe tomatoes. It all depended on what you were growing, of course.

What I did in my 100 square feet was to divide my garden plans so I did half and half (a two year rotation with alternating crops on alternating years). I grew a little bit of a lot of different things, and chose which went together by what made good companions. So, on year one, half my crops went into plot A and the other half my crops went into plot B. The next year, the reverse.

I was there three years, and it went well. I added compost every spring, and fertilized with seaweed and fish throughout the season. Never had any problems.

Now, if your space dictates that you can only plant certain crops in certain places due to how much sun you have, you do what you have to do and hope for the best. If you are asking what the best practices are, and you can't live up to the ideal, that doesn't change what the ideal is, it only means you have to compromise.

You might never have problems. Or maybe you will. But everything in life has pros and cons and nothing is guaranteed. We can only do the best we can and be honest about the risks.

Really interesting and helpful thread. Thanks, Peter, for the demystified explanation of the benefits. My yard is tiny, but I will try to grow beans this year where I grew tomatoes last year. I think my yard isn't big enough to benefit from the microbial stuff, but maybe I'll get some nitrogen into the soil. I think, I hope, that I have good soil bacteria to get into the bean roots-- I see lots of worms and things seem to grow pretty well.

from growing up on a farm and planting huge acrerage / crop rotation is a must due to the huge cost of soil amending / 40/ 80/ 100 acres or more fert and replenishment it adds up fast / but in a back yard garden its not that big an issue to replenish the soil with fert and amendments / besides most of us do it anyways when we start prepping our beds for veggies in the early spring / so no rotation is not a must for a small backyard garden / i dont rotate and have a pretty good garden

This is the organic Gardening thread! Some interesting points have been expressed in the thread.

One of the key organic principles is replenishment; of course referring to nutrients and organic matter. The use of cover crops, rotations, intercropping, green manures, recycling refuse and manure to name a few, fill the replenishment options. That certainly does not preclude the organic amendments for deficient nutrients or adjustment of pH.

The OP specifically poised the rotation topic. It compels me to ask of those who plant the same plants in the same location, "What do you proclaim to be the cause of pests and disease?" If a plant(s) succumbs to a pest or disease in that location from year to year, do you not think that the origin might be the soil?

Rotation is primarily directed at avoidance of direct exposure to pests and disease that exist in the soil. While there is also truth in healthy soil reducing the impact of pests and diseases, moving the host plant to a fresh location reduces the incidence. The continuos presence of the host (as mentioned by Peter) continues the cyles of pests and disease without interruption. By rotating crops you insert a non-host species or one that is antagonistic to that pest or disease (i.e. - marigolds for nematodes).

Diversity of planting is also an enhancement, especially for pests and disease. The availability of nutrients is also a factor in the growth rate of the plants; a plant growing too fast or slow suffers stresses which are invitation to pests and diseases.

Being in a zone 5 and growing many long season heirlooms I am compelled to start most for transplanting. Timing the starts attempts to have a strong plant able to adapt easily when placed within the suitable growing conditions. Transplants also permit me to properly prepare the beds.

For me rotation means having a growing plant or crop in the soil 70-80% of the year. A fall green manure and/or cover crop is part of the plan. Timing of fall sowing may require inter-seeding to permit suitable germination and growth before first frost. Turning under the spring growth prior to transplanting adds nutrients and organic matter which must be given 2-3 weeks for initial decomposition; so not to starve the transplants of nitrogen.

Rotation does have a part in the small and medium scale. For my two distance-separated plots totalling nearly 10,000 square feet it is simple to rotate plantings by simply leapfrogging beds. My five year rotation plan shifts each wide (3 feet) bed about 21 feet (including the paths).

For nutrient replentishment I strictly limit amendments to compost, composted manure (cattle/horse) and green manure. My soil is tested every three years for comparison. My nutrient management plan is based on improvement versus maintenance. My primary plot is sand which has produced for nearly 40 years. A new plot of silt-loam on a beef farm has been in production for me over five years.

My only bad year was 2009 due to very brief summer weather and only about 30% sunny days. I'm sticking to my rotation plan.

Another significant aspect of the rotation requirement relate to diversity of soil organisms. By changing the planting you also support different organisms. The bacterial population like the quick consumption materials; translate to the 'fast' food nature of the simple structured organic matter. The fungi are the full meal population that consume the more complex matter.

By varying the organic amendment you contribute to the related organisms. The presence of both bateria and fungi can permit a more diverse recycling of the available amendments within the production. Bacteria remain the primary residents since most amendments are of simple structure.

As in composting, you need both bacteria and fungi (plus the others) to thoroughly decompose the range of materials.

Reeeeeeealy?
U guys argue far too much. This is soo the most NOT useful thread.

Actually, I find this a very interesting thread.

The only thing not mentioned above is that crop rotation also helps control weeds. By planting at different times, the weeds do not get used to a pattern they can exploit.

jajm4, are you talking about three year rotation of Robert Rodale of Rodale Press.
Getting the most from your garden Page 140
Heavy feeders- cabbage,broccoli,beets.
Light feeders-peppers,onions,carrots.
Soil builders- clover,peanuts,peas,beans.
This is just one of 4 reason for rotating crops:
Disease control
Insect control
Weed control

I can see that the "nutrient-balancing" reason for crop rotation is arguable. Furthermore, rotation won't defeat insects, because the are mobile and can detect their favorite food from at least a quarter of a mile away. Not-with-standing the above, I have been a devoted rotator since it was taught by my elementary school teacher in England during the war. The #1 reason is to fool the microbes (usually fungi) that present soil-borne diseases. They always lie in wait in the soil in non-pathagenic population levels, until their favorite food is grown -- then their poulation increases by - let's say - 100-fold. If you grow the same crop in the same soil a second year, the population increase would be 10,000-fold, and in three years 1,000,000-fold. So eventually, in an organic system, crop failure would be inevitable. The other reason, I have learned over the last 40 years, is that nitrogen has to be provided by growing legumes in rotation. I knowe of no safer way to provide sufficient nitrogen in organic culture. Regards, Peter.