Organic Household Wastes as a Nitrogen Source in Leek Production

Abstract

Composted and anaerobically digested organic household wastes were evaluated as N sources in leek (Allium porrum L.) production in an incubation experiment without plants and in an outdoor frame with plants.Their N-fertilizing values were compared with that of chicken manure.Both experiments were conducted on four soil types (sand, two loams and a clay).After 168 days of incubation the percentage of inorganic N of total N applied was 40 -60% for slurry, 15% for compost and 20 -30% for chicken manure.Only in treatments with chicken manure was net N mineralization achieved in all four soils at the end of incubation.In the frame experiment, between 5 and 20% of the slurry N, 1% of the compost N and 6% of the chicken manure N was utilized by the above-ground leek crop.Slurry gave 1-20 Mg ha -1 higher leek fresh weight yield than did compost or chicken manure.The highest fresh weight and N yields were achieved on the finer textured loam.The experiments showed that the amounts of plant-available N from slurry or compost were too small to support a leek crop with a high N demand towards the end of the growing season.