CHANGES IN SOME CHEMICAL PROPERTIES OF THE SOIL UNDER GRASS SWARD AND HERBICIDE STRIPS IN APPLE ORCHARDS

Research was carried out in 1986–88 in seven apple orchards located in Poznan region.
In each orchard there were 3 levels of nitrogen fertilization: 0, 60 and 120 kg N/ha in NH₄NO₃ form.

The dominant system of soil management was – herbicide strips in tree rows and grass sward alleys (system I, 6 orchards). In one orchard, the herbicide strips were maintained in tree rows with clean cultivation between them (system II).

The samples of soil were taken from the depths of 0–20, 20–40 and 40–60 cm in 1986 and from 0–20 cm in 1987–88 at 3 dates (in mid-April, mid-June and at the end of July).

It was found that in system I, the soil at a depth of 0–20 cm under the grass sward strips had higher levels of: pH, humus content, cation exchange capacity, K and Mg.
The contents of N-NH₄, N-NO₃, K and Mg decreased during the vegetation period, but no marked differences were found in P content.
In system II, herbicide strips showed higher levels of N-NH₄, N-NO₃ and P, but lower levels of K and Mg in comparison with clean cultivation belts.
Nitrogen fertilization lowered the content of K and Mg either in the herbicide or in the grass sward alleys.

International Symposium on Diagnosis of Nutritional Status of Deciduous Fruit Orchards

A. Komosa

https://doi.org/10.17660/ActaHortic.1990.274.25