Nitrogen: yields, spear quality and Nmin-residues of asparagus

摘要

Asparagus cv. Huchtels AM33 was planted at 13 000 plants/ha on sandy soil in a trial at Ingelheim in 1986 and fertilized with mineral N every June to give N concentrations of 30, 60, 90 and 120 kg/ha. It is concluded that N fertilization should be based on analysis of soil N, especially if organic fertilizers are used. Excessive N supply can result in less vigorous spears, while N deficiency reduces quality. Soil N concentrations of 90 kg/ha in the 0-90 cm layer after the third year of cultivationare recommended, both for optimum plant growth and minimum groundwater contamination.