Deposition of spray liquid on the soil below sugar beet and potatoes after applications during the growing season

The aim of this study was to investigate the proportion of spray liquid applied in a typical application that was deposited on the soil surface below the crop. This part of the spray is not only an application loss, but it also constitutes a primary source to leaching. The investigation was carried out during 1999-2001 in sugar beets and potatoes. Applications were carried out at approximate intervals of 10 days during the whole growing season in both crops, which were grown in rows. The results show that a high proportion of the spray liquid reaches the soil below the crop during applications at early growth stages, which correspond with stages when weed control is practised. At later growth stages soil deposition declined and reached values below 10-15% of the applied dose in sugar beet (GS 39) and 5-10% in potatoes (GS 59-79).