Is it true?

[GIB]

Is it true that you must not grow potatoes on the same area of ground two years in a row? If so can you tell me why this is please.

thank you.

[Cider Boys]

Simply, when you grow any crop it uses nutrients in a ratio depending of the type of plant. If you grow potatoes without redressing the exhausted nutrients they will not grow so well and produce a lower yield. (All other things being equal.)

However the main reason to rotate especially potatoes is to prevent any build up of pests and diseases that the crop is subject to. Saying that, in a garden/allotment situation it is often difficult to always stick to a rotation due to lack of space and timings of planting and I have successfully grown new potatoes after main crop potatoes using a good application of fertilizers.

Good practise says rotate but this is not an ideal world.

It would also be interesting to learn from the Jersey potato growers on their methods.

Barney

[GIB]

Barney

Many thanks for your reply.

The reason i aksed is that i put a good layer of well rotted manure on the piece of ground that i grew them in the 2006 season and then planted them in the same place again this year with no adverse affects at all. There were no signs of any disease on them and they cropped very well so i think i will do the same again next year as i am limited for growing space.

thanks

[Allan]

There may be another problem inasmuch as sometimes a significant number od tubers get left in the ground and grow the next season which could be a nuisance especially if you are changing to another potato variety.
Allan

[peter]

To reduce your chance of catastrophic blight attack.

[Mike Vogel]

Gib, I think Peter has given the most telling reason. Blight is inclined to stay in the soil and overwinter and there will probably be spores in the soil even if this year's crop has not been obviously affected.

Brasicas are another crop which need moving around, because of the potential of club-root to build up where they are grown.

Organic gardening pundits have a lot to say about rotation, but ranking high among their advice is not to get too hung up about it, for reasons given by Colin and others here. They also put emphasis on rotation of potatoes and brassicas.

The nutrition argument gets surprisingly little attention from them, except the value of the nitrogen from legumes for following brassicas. The most often mentioned thing here is the value of heavy doses of manure or compost used for crop A being excellent for crop B the next year. So after potatoes [with heavy manure], grow roots [which don't thrive on heavy manuring but will on old manure already part of the soil]. Books often use the expression "... with manure from the previous crop" when advising on growing crops which thrive in these conditions.

Compliments of the season.

mike

[Mike Vogel]

Sorry, Cider Boys, I meant to acknowledge your comments but cited "Colin" instead. My apologies to you - and to Colin.

mike