| Abstract: | Nutrient displacement and water balance under oat crop on a Cambisol from loess colluvium Field experiments with oat on a loess soil were carried out from January until December 1978 on a since 6 years cultivated small plot area to study the water budget and the influence of different nitrogen fertilization on nutrient leaching. Ceramic cups were used to obtain soil water samples at a depth of 100 cm at two-week intervals, two years after application of a compost and after the application of artificial nitrogen fertilizers. Main components of the water balance were calculated with the use of a computer simulation (CSMP) program, the performance of which was controlled by tensiometer measurements. It was calculated that 214 mm of the total 608 mm rainfall in 1978 drained out of the profile, and that the cumulative evapotranspiration was 448 mm. This study included 70 stress days during which evapotranspiration was reduced. Chemical analyses of the soil solution samples showed that an intensive nitrogen fertilization surrendered to a significant increase in the nitrate displacement, whereas the average yearly losses of other nutrient elements, including potassium, phosphorus, calcium and magnesium were unchanged. The use of the compost fertilizer resulted in a significant increase in the sodium concentration of the soil solution samples. |
