Organische Düngung intensiv genutzten Dauergrünlandes im Vergleich mit Mineraldüngung - Ergebnisse eines 22 jährigen Versuches auf Wiese und Mähweide.

In a 22-year-old experiment in Southwest Germany, the effects of different fertilization systems (organic and mineral fertilizers) on permanent grassland were investigated. The effects were investigated under cutting and mown pasture with two grazing periods per year. The experiment had 8 fertilizer treatments and 3 replications, the size of field plots were 25 m2 in area. Dry matter (DM) yields and mineral contents in soil and forage (P, K) were measured. The botanical composition was investigated each second year. Maximum DM yields were obtained by mineral NPK fertilization and a treatment called ‘alternating fertilizer’, with yearly alternating use of farmyard manure, liquid manure and mineral NPK. The application of composted farmyard manure reduced DM yields. The additional application of stone-meal and metallurgical lime to slurry did not increase the effects of untreated slurry on yield. Fertilization with slurry increased the proportions of grasses, whereas farmyard manure increased forbs. The proportion of legumes was increased by PK and by fertilization with slurry with lime