THE FATE OF N FROM COMPOSTED POULTRY MANURE WHEN APPLIED TO FORSYTHIA AND CHRYSANTHEMUM

Abstract

`Lynwood Gold' forsythia and `Jessica' chrysanthemum were grown for 12 weeks in a nursery mix consisting of 5 parts composted pine bark, 1 part composted hardwood bark and 1 part sand. Fertilization was by topdress applications of composted poultry manure at rates of 1, 2 and 3 g N per container, resin coated slow release fertilizer at 3 g N per container, or with constant liquid fertilization at 200 mg N per liter. Leachate samples were collected weekly and nitrate, nitrite, ammonium and total nitrogen determined. At 12 weeks, plant dry weight and the amount of nitrogen in the plant, media and leachate determined. Total nitrogen loss in the leachate for the compost was rapid during the first three weeks and then fell to low levels. The resin coated fertilizer released a higher and constant nitrogen flux during the study than the composted manure but total nitrogen loss over the 12 week period was lower than for compost. The leachate nitrogen in the constant liquid fertilization treatment increased during the study. The relative proportion of nitrogen in the medium, compost and leachate will be discussed.