Especially rose plants (Rosaceae) are affected by the phenomenon, which makes it difficult to replant species of this family on the same land. Soil fatigue lasts for a very long time, usually 10 to 25 years, and is defined by weaker growth of the crop plants. There are various explanations for its occurrence – but the exact causes are still being researched.
Theories on soil fatigue
Soil fatigue (or post-planting disease) is a growth or yield depression. Typical of soil fatigue is that it cannot be remedied, or can only be remedied incompletely, with proven cultural measures – for example, with an intercrop, green manure or targeted crop rotation. Although a fertiliser application can improve the growth performance of a weakened plant in the short term, the effect unfortunately does not usually last long.
The exact causes are still not fully understood – but there are two possible explanations:
- the affected plants gradually poison themselves through excretions from their own plant roots, which remain in the soil.
- certain micro-organisms or fungi that specialise in the decomposition and conversion of root residues in the soil are responsible for the regrowth problem.
Soil fatigue in fruit species and roses
The rose family (Rosaceae) is particularly affected. It includes most of the known fruit species and fruit trees: apple, pear, stone fruit species such as cherries, plums, apricots, almonds, peaches and nectarines. And of course strawberries and raspberries as well as the rose.
Pome fruit in particular is often affected: If an apple tree is uprooted and a new tree is planted in the same location, a growth depression of 20 to 30 percent must be expected.
Modern rose varieties flower on this year’s wood. However, if this is insufficiently developed, the flowering will of course also suffer.
Soil fatigue is less pronounced in stone fruit. In the home garden, a cherry can be planted after a cherry or an apricot after an apricot. Planting stone fruit after pome fruit is also possible.
These measures help against soil fatigue
Plant roses consistently in unused soil where roses have never stood before and where no pome fruit tree has stood before! If this is not possible for reasons of space: dig a generous pit about 50 cm deep and fill the planting hole with garden soil from an uncritical area. To be on the safe side, you should plant pome fruit a little away from the growing site of the preceding tree (also pome fruit). With strawberries it makes sense to plant in the same place only every 3 to 5 years. Raspberries need to be replanted at certain intervals (after about 7 years). Here, too, it is essential to change the location. By introducing organic matter into the replanting soil, the soil life is activated so that, for example, harmful fungi are suppressed. A good start is very important – provide the young plant with sufficient nutrients and plant a fruit tree in autumn if possible.