The effect of a ploughpan in marine loam soils on potato growth. 1. Physical properties and rooting patterns

Abstract

The ploughpans studied on old land had a very small number of large pores, a large penetration resistance and a diminished aeration. On recently reclaimed land a very weak ploughpan was present but a severe ploughpan with similar characteristics as on old land could be established relatively easily. A too high mechanical impedance has to be considered as the primary factor severely hampering root growth in these ploughpans. Especially in a relatively dry growing season, water supply to the root system, therefore, was clearly suboptimal. Removal of the ploughpan on old land only slightly increased the effective rooting depth because of a hardly rootable subsoil. Roots easily penetrated the subsoil on new land.