Potato growing according to the CULTAN-system.

摘要

The ammonium-nitrogen nutrition system CULTAN (Controlled Uptake Long Term Ammonium Nutrition) is a depot system where ammonium is placed in a line depot close to the root zone. For potatoes on sandy soils 10 cm depths and on loamy soils 15 cm are used. Results from 2003 field research near Julich, western Germany, are shown. The field has a deep loam soil and potatoes were planted with minimum tillage at a plant population of 42 000. Six fertiliser treatments and four replications were used. Results showed highest total yield of 85.6 t/ha with 100 kg N/ha as ammonium sulphate and DAP [?diammonium phosphate] in "bulk blending" technique added with 1.5 t gypsum. The treatment with 129 kg N/ha mineral nitrogen as calcium ammonium nitrate (CAN or KAS, in German) produced 69.1 t/ha. The Nmin content was 71 kg N/ha in all treatments. [No details on production economics or leaching are given]..