The influence of artificial vertical macropores in a compacted soil on the growth of winterwheat. I. Growth of winterwheat on an alfisol derived from loess

In field experiments on a compacted alfisol it was investigated. how artificially made vertical macropores in the compacted structure influence water extraction and growth of winterwheat compared to the compacted structure without vertical macropores and LO the loosened structure. The experiments were carried out in two subsequent years with different pre- cipitation (308.0 and 440.1 mm in the period of November until August of both growth periods). The influence of the different soil S~NCIUR was most pronounced dur- ing periods of increasing water tension. Compared to the compacted structure, water extraction as well as yield was improved by the vertical artificial macropores to a similar extend as by the loosened structure. Both structures increased water extraction from deeper parts of the soil (25-50 cm). The beneficial effects of the vertical macropores were more pronounced in the dry compared to the wet year. Despite of the unequal distribution of roots in the Compacted structure with vertical macropores. water extraction from the soil between the macropores was not negatively affected.