One year after draining and extensively loosening heavy-clay soils, irrigation water was sprinkled over it daily for 10 h for a 3-day period, using a 10 mm h-1 rate, perpendicularly over plastic drains. Five days after the initial application of water another 140 mm of water was applied, and on the 7th day, an 80 mm solution containing complex chemical (NPK) nutrients was also spread over the soil plots. The deep loosening tracks modified the soil's hydraulic properties by decreasing bulk density and increasing soil porosity, water permeability and, implicitly, soil water flux. Solute penetration also showed a preferential character. Under the moist conditions of the heavy-clay soil studied, these tracks were very active soil macropores that had a role similar to that which cracks have on dry soils. Soil water volume and flux as well as drain discharge decreased curve-linearly with time following field saturation over several days of internal drainage. The pipe drainage system combined with deep loosening was an efficient, yet expensive measure in the land reclamation of these heavy-clay soils. When discussing priorities for the hydro improvement measures needed to control soil water, it could be said that the priority is to prevent excess rainfall in these soils during spring, while secondly it is important to irrigate them during summer time.