Utilisation of manure composts by high-value crops: Safety and environmental challenges R. Moral a, * , C. Paredes a , M.A. Bustamante a , F. Marhuenda-Egea b , M.P. Bernal c a Dept. Agrochemistry and Environment, Universidad Miguel Hernández de Elche, EPS-Orihuela, ctra. Beniel Km 3,2, 03312-Orihuela, Alicante, Spain b Dept. Agrochemistry and Biochemistry, University of Alicante, 03080 Alicante, Spain c Dept. Soil and Water Conservation and Organic Waste Management, Centro de Edafología y Biología Aplicada del Segura, CSIC, P.O. Box 164, 30100 Murcia, Spain article info Article history: Received 6 June 2008 Received in revised form 28 November 2008 Accepted 3 December 2008 Available online 20 January 2009 Keywords: Manure Composting Added value properties Organic fertiliser Suppressiveness abstract The intensification in livestock production has increased the need of efficient treatments of waste streams especially to preserve as much as possible, the nutrients into the soil-plant system. Composting is a cheap, efficient and sustainable treatment for solid wastes that is always included in any manure treatment scenario. In this paper, an overview about the environmental and safety challenges of com- posting of manures is made considering the compost quality requirements established by the main demanding sectors. Co-composting and additive strategies are presented as feasible options for the improvement of compost quality. For quality evaluation of manure compost, the use of both classical and innovative instrumental techniques could increase our knowledge about added properties in com- post, especially those related to organic matter stability. Ó 2008 Elsevier Ltd. All rights reserved. 1. Introduction Agricultural management is quickly changing. A new view in relation to the agricultural systems is little by little taking place, including environmental and sustainability concepts without for- getting the gross production. Several treatment approaches have incorporated compost as a key operation in advanced management systems. Moreover, it must be considered that the agricultural management through the compost use supposes a brake reduction to the greenhouse effect, with a potential C sequestration in the arid zones of approximately 0.10–0.20 tons C/ha/year for applica- tion doses of 20 Mg/ha/year (Lal, 2000). However, the development of high-quality compost from organic wastes must be focused on specific agricultural activities in order to justify the associated pro- duction cost of compost and also to obtain the compost quality de- manded by each user. Several agricultural sectors could pay for high-quality composts, especially the sectors of nursery crop that uses soilless media, orchard mulching, and organic farming. In relation to the nursery crop sector, the widely extended use of peat as growing media constituent is a concern because of the carbon reserves in peatlands are being rapidly depleted due to mining of peatland resources. Peatlands are a sink for atmospheric carbon and their carbon uptake accounts for about 12% of current human emissions. Although they are low in biodiversity, their fauna and flora are distinctive and many groups are confined to this habitat. In the EU alone, it has been estimated that 38% of the total of peatlands have been severely affected by commercial harvesting (Raeymaekers, 2000), while 3.39 million m 3 of peat is the total amount used annually by the UK horticultural industry (ODPM, 2003). For all these reasons, the British Government has proposed a very strict legislation in this aspect, with a reduction of 10% before 2010 in the use of peat as growing media and soil im- prover, as well as the encouragement of the re-use of organic wastes as growing media components instead of their spill. There- fore, composts can be considered as an alternative and low-cost growing media instead of peat for plant production. Usually, high-quality compost has suitable characteristics for their use in potting media, such as high hydraulic conductivity, air porosity, and stable and non-phytotoxic organic matter, and potential sup- pressiveness capacity against soil-borne diseases. The use of compost in mulching is becoming a rising agricul- tural practice. This is because composts as mulching agents can de- crease plant stress, soil-borne pests and diseases, reduce fluctuation in soil temperatures and soil erosion, provide weed suppression, and increase soil quality. In New South Wales (Aus- tralia), wide extension trials with manure compost showed savings up to 70% mineral fertilisers in the first year of mulching applica- tion (Recycled Organics Unit, 2006). In relation to this, Gonzalez and Cooperband (2002) found that combining amending and mulching management improved the yield and sustainability of field nursery production of ornamental shrub, increasing saturated 0960-8524/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.biortech.2008.12.007 * Corresponding author. Tel.: +34 966749652; fax: +34 966749711. E-mail address: raul.moral@umh.es (R. Moral). Bioresource Technology 100 (2009) 5454–5460 Contents lists available at ScienceDirect Bioresource Technology journal homepage: www.elsevier.com/locate/biortech