Nitrogen Balance in Fertilizer Application and Plant Production

Abstract

The investigation comprises several agricultural crops, a Karup locality (56°16' N, 9°9' E) with an average annual precipitation of 775 mm and coarse sand (soil 1), and a Tåstrup locality (55°40' N, 12°18' E) with an average precipitation of 600 mm and clay with fine sand (soil 6). Soils 1 and 6 have 5 and 8 t N/ha in organic matter, respectively, to 50 cm soil depth and an average effective root zone capacity for available water of 60 and 170 mm.

Data for soils 1 and 6 in kg N/ha as average (with great annual variation) were for spring barley found to be around the following: mineralization 75 and 135, denitrification 5 and 20, uptake in harvest 105 and 155, leaching 65 and 40, and spring storage 10 and 60, respectively. Wintering and late growing crops reduce the leaching by around 20 kg N/ha. The nitrogen leaching from sandy soil is clearly influenced by variation in fertilization whereas the leaching from clay soil is only a little affected.