title: Reduced turning frequency and delayed poultry manure addition reduces N loss from sugarcane compost.
abstract: Composting is an effective method to recycle biodegradable waste as soil amendment in smallholder farming systems. Although all essential plant nutrients are found in compost, a substantial amount of nitrogen is lost during composting. This study therefore investigated the potential of reducing N losses by (i) delaying the addition of nitrogen-rich substrates (i.e. poultry manure), and (ii) reducing the turning frequency during composting. Furthermore, we tested the effect of compost application method on nitrogen mineralization. Sugarcane-waste was composted for 54days with addition of poultry manure at the beginning (i.e. early addition) or after 21days of composting (delayed addition). The compost pile was then turned either every three or nine days. Composts were subsequently applied to soil as (i) homogeneously mixed, or (ii) stratified, and incubated for 28days to test the effect of compost application on nitrogen mineralization. The results showed that delayed addition of poultry manure reduced total nitrogen loss by 33% and increased mineral nitrogen content by >200% compared with early addition. Similarly, less frequent turning reduced total N loss by 12% compared with frequent turning. Stratified placement of compost did not enhance N mineralization compared to a homogeneous mixing. Our results suggested that simple modifications of the composting process (i.e. delayed addition and/or turning frequency) could significantly reduce N losses and improve the plant-nutritional value of compost.
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
authors.forename: S
authors.initials: S
authors.lastname: Bryndum
authors.affiliation: Latin American Chair of Agroecology and Agrobiodiversity, Center for Research and Higher Education in Tropical Agriculture (CATIE), CATIE 7170, Turrialba 32501, Costa Rica.
authors.forename: R
authors.initials: R
authors.lastname: Muschler
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
authors.forename: A
authors.initials: A
authors.lastname: Nigussie
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark.
authors.forename: J
authors.initials: J
authors.lastname: Magid
authors.affiliation: Department of Plant and Environmental Sciences, Faculty of Science, University of Copenhagen, Thorvaldsensvej 40, 1871 Frederiksberg C, Denmark. Electronic address: adn@plen.ku.dk.
authors.forename: A
authors.initials: A
authors.lastname: de Neergaard
mesh_terms: D000818:Animals; D000076282:Composting; D008372:Manure; D009584:Nitrogen; D011200:Poultry; D031786:Saccharum; D012987:Soil
chemical_list: D008372:Manure; D012987:Soil; D009584:Nitrogen
keywords: Compost; Fertilizer-value; N mineralization; N-enrichment; Soil incubation; Turning frequency