Organic Gardening: Crop Rotation

The concept and practise of crop rotation is not a new one there are ancient Roman, African and Asian archaeological references to its practice and theory. But it was not until 8 - 13 CE during the global Muslim Agricultural Revolution (MAR), that it became well known and widely introduced into global farming practises. It is only with the fairly new advent of inorganic pesticides and fertilisers that crop rotation lost favour and was mistakenly replaced. There is however a return to or innovation of these old practices through the systems of sustainable farming as seen in organic farming, permaculture, polyculture etc. It is becoming undeniably self-evident that modern petro-chemical reliant commercial farming is not only un-sustainable but increasingly damaging to the environment.

Going back to the MAR for a bit because within it we can see the roots of modern farming in some very fundamental concepts and practises that changed humanity forever (perhaps even more than we think see article Evolution in Action). What the MAR did was to put forward major innovations to agriculture of the time. The Muslim trade routes saw the introduction of these innovations inconjunction with an incredible amount of new food crops, especially into Europe that had been mainly wheat farming up until then. Among the new crops were cotton, rice, aubergines, bananas, figs, lemons, flax, oranges, apricots and sugar cane.

There are four main reasons to practise crop rotation and they are Soil Depletion, Disease Prevention, Pest Control and Weed Control. Different crops not only utilise different properties of the soil like minerals and nutrients, but they themselves also change the soil with their root structures and outputs too. If one plants the same crop year after year in the same soil or garden bed, the soil will without aid become leached of all that the specific crops requires in order to grow. The yield of that crop will gradually dwindle until it is not worth sowing any more. There are three solutions to this problem.

One; move to new land and join a slash and burn farming culture that has in itself become nearly redundant in the face of pressing population and environmental concerns. Two; join the modern commercial culture that is wholly reliant on petro-chemicals for fertiliser and pesticides in combination with grow once hybrid seed. Or alternatively ply your land with massive amounts of manure and compost which whilst being organic might perhaps break the bank. Three; join a culture of crop rotation combined in a dynamic and innovative way with other elements of organic gardening such as companion planting etc.

Diseases, Pests and Weeds are perpetuated by continuous mono-cropping; nearly all wild plants, diseases and pests are fairly specific in what plants they attack or grow amongst. The plants they are attracted to are usually within the same family. Continuous mono-cropping provides the perfect kingdom for plant associated disease and pests, a kind of guaranteed all you can eat buffet. The only way to break these cycles without crop rotation is through the application of toxic chemicals, a damaging and unsustainable process. Bring all four reasons together and you have a pretty good argument for the resurgence and innovation of crop rotation back into home and commercial agriculture.

There is a wealth of specific crop rotation methods available for study; after all we have been practicing it for at least 700 years. So I will lay down three of them to give you the idea of how to go about it. The thing is to see the core system concepts involved and then apply them to your particular and unique situation in a dynamic way. These specific methods are not to be adhered to but rather used as a basic framework.

The 3 Year 4 bed Crop Rotation system.

Divide you garden into 4 beds or multiples thereof like 8, 16, 24 etc. In year One we start off with the beds in order A-D.

A is for Root crops such as Beetroot, Carrots, Jerusalem Artichokes and Parsnips etc.

B is for Brassicas crops such as Broccoli, Cauliflowers, Cabbages, Kale, Radish, Swede, Turnips and Kohl Rabi etc.

C is for those heavy feeders such as Courgettes, Beans, Peas, Celery, Sweet Corn, Potatoes, Marrows, Spinach, Tomatoes and Leeks etc.

D is for long term crops such as strawberries, blackberries, rhubarb and herbs like Rosemary etc. Give some though to this bed especially as these crops will be in there for 3 years or more.

Now take a look at the diagram you will see how the crop rotation proceeds, it is fairly simple A moves to B etc, but D remains for three years before going to the top and thus releasing that bed for a new pattern in year four. In other crop rotation methods D remains stationary permanently and is given over to fruit trees and other permanent crops. Or it is just left fallow for two years with a final annual legume crop like clover in the third year that is green manured into the soil for the fourth year and the subsequent crop of C heavy feeders.

The 5 year crop rotation system.

Another way to achieve crop rotation is to keep each bed irrespective of its neighbours or additional beds on a five and six year rotational systems that has its roots in the plant families.

1) Brassicas: Cabbage, Cauliflower, Radish and Swede etc.

2) Legumes: Pea, Bean e.g. Broad, French and Runner etc.

3) Onions: Onion, Garlic, Shallot and Leek etc.

4) Potatoes: Potato, Tomato, Aubergine etc.

5) Umbellifers: Carrot, Parsnip, Parsley, Celery, Florence and Fennel etc.

The 6 Year crop rotation system.

1) Roots: Carrot, Parsnip, Beetroot, Chicory, Swiss Chard and Celeriac etc.

2. Alliums: Onions, Garlic, Leeks, and Shallots etc.

3. Legumes: Broad Beans, Runner Beans, French Beans and Peas etc.

4. Brassicas: Cabbage, Cauliflower, Sprouts, Broccoli and Swede etc..

5. Solanaceae: Potatoes and Tomatoes etc.

6. Cucurbiteae: Courgettes and Squashes etc.

Bear in mind that these crops are not to be mono-cropped but interplanted with appropriate Companion Plants wherever possible. There are varying degrees that one can implement companion planting with crop rotation but it always depends on your unique situation. Many larger scale organic farmers find themselves reducing the amount of interplanting with companion plants to achieve a higher efficiency in time spent weeding and harvesting. After all you can’t be hacking your way through a jungle every time you need to harvest produce for sale. The trick is to come to a dynamic compromise between all these factors that will ensure a long term sustainable organic gardening endeavour be it for sale or home consumption.

As I said before these are only guidelines, the real work comes in finding out what works for you in a systematic manner and being shrewdly dynamic. I mention this without fail in each organic gardening article in this series because it is a key issue in being a successful organic gardener/farmer. It requires a constant observation that allows the land to communicate in an error feedback what works for you locally. Take this knowledge to be innovative and dynamic, that is find news ways for old knowledge and be ready to adapt at any moment to the changes that occur. All the principals of crop rotation are applicable to any sized garden from balcony pots to large farms. So if you haven’t tried it out give it a go you might be quite surprised at the difference it will make. Also keep in mind all the other elements of organic gardening like design, compost and pest control and blend them together to arrive at a holistic solution that uses and benefits from all the elements.

In this series: . Weed Control . Compost . Pest Control . Companion Planting . System Design . Crop Rotation .

Organic Gardening: Crop Rotation was written By Ivor W. Hartmann.