Crop Rotation and why It's the way to go!

Crop rotation is one tried and tested method to make growing food easier in the long run. Grouping annual vegetables according to their similarities, nutrient and soil requirements pays.So why? The first and foremost reason is pests I'm refering mainly to soil born like nematodes and fungi.
Plants and parasites have evolved together and therefore some parasites only effect one type of plant and if you keep planting in the same position years after year you give the parasites a chance to build numbers in the soil waitng for their host plant to return. If you move the host plant to another position by rotation you can actually starve the parasite out of your garden bed with no chemicals. Yea now thats great!
There are thousands of examples of this dual evolution in nature Eg wasps and trees. Some species of wasp only polinate a particular species of tree - take away either and say goodbye to one.

Plants have evolved different root syetems some are shallow extracting nutrients from only the top 20cm of soli and some go deeper like corn extracting nutrients from deeper in the soil. They also like slightly diferent soil PH.

Here's how I've broken up my veges - I havn't included some well know temperate veg's as the growing season is too short in Cairns.
1. Tomatoes/Capsicum you could include egg plant in this group but I don't put egg plant in a bed - this group prefer a slightly acidic soil.

2.Legumes - Nitrogen fixing. Fix some of their own nitrogen from the air via their bacteria buddies. Prefer slightly alkaline soil. Add some Dolomite before planting

3.Leafy - asian Veg and lettuce

4.Cucumber, Zuccini, Squash and Corn

5.Onions all types and root crops like carrots

6.Green Manure

7.Strawberries
Keep these groups rotating around to a different position from year to year to minimize soil born parisites and to for a better balance in nutient distribution and to maintain a more neutral soil PH
So among other things Crop rotation will save you in the long run.