Is it really necessary to rotate runner beans?

Question

A firm believer in 3-year crop rotation, I sow my runner beans in a different plot every year. After they crop, I dig their stems and roots into the soil, to replenish it with their captured nitrogen; I then dismantle the bamboo support frame and reconstruct it elsewhere. To avoid this hassle, several of my gardener friends dig in plenty of manure and use the same plot year after year - and their plants thrive and crop well (sometimes better than mine!). If their long-term failure to ‘sow by the rules’ has depleted the soil of certain nutrients, it certainly isn’t apparent. Is it really necessary to rotate runner beans?

Answer 1

The manure is going to include other nutrients as well nitrogen - there's probably a sufficient spread of nutrient types that depletion is slow or non-existent.

One advantage of your rotation is that your beans are adding nitrogen to the soil in different parts of the garden. You should also be less prone to pests - which it sounds like isn't currently a problem for you and your friends in your area at the moment.

Answer 2

If you work new soil into your beds every year I don't see any point in crop rotation. Composting your stems and roots, along with some manure, kitchen scraps (coffee grounds, etc), and leaves during the summer and then working that into your soil prior to planting your new crop next spring is a great way to keep your soil nutrient level fresh.

Answer 3

The reason people like to do crop rotation is to avoid pests staying in the soil, and to replete nutrients lost from the soil. But some people like Elaine Ingham say that the soil will not be depleted of nutrients in anyone's lifetime if you keep the soil biology intact. Ruth Stout found the same thing. She mulched year after year and kept planting the same crops without rotation with no problems. And she replenished the soil biology by using hay which fed the worms and microbiota, and cast some meal over the hay. A woody material helps also to replenish the soil fungi which hold a significant proportion of the soil micronutrients in their bodies.