Effects of beer factory sludge on soil properties and growth of sugar beet (Betavulgarissaccharifera L.) Cihat K€ ut€ uk a, * ,G€ okhan C ß aycı a , Abdullah Baran a ,O guz Bas ßkan a , Roger Hartmann b a DepartmentofSoilScience,FacultyofAgriculture,UniversityofAnkara,06110Ankara,Turkey b DivisionSoilPhysics,SoilManagementandSoilCare,FacultyofAgriculturalandAppliedBiologicalSciences,UniversityofGent, CoupureLinks,653-B-9000Gent,Belgium Received 6 November 2002; received in revised form 15 February 2003; accepted 3 March 2003 Abstract The possible use of beer factory sludge (BFS) for an agricultural purpose was investigated with sugar beet (Betavulgarissac- charifera L.). BFS was air dried and sieved through a 4 mm mesh before application to a soil (Typic Xerofluvent). Afterwards, the BFS was mixed with soil at a rate 0, 10, 20, 40, 80 and 160 tonnes ha 1 . The mixtures were than put into pots and kept in the greenhouse for an incubation of five months. During the incubation, pH, the electrical conductivity, the organic matter content, NH þ 4 -N and NO  3 -N content were regularly measured. At the end of the incubation period, sugar beet seeds were sown into the same pots. After a growing period of six-months the sugar beet plants were harvested, and yield and quality parameters were determined. BFS increased leaf and root yield. However, the effect of BFS on leaf growth was more pronounced than on root growth. The highest sugar content, refined sugar content and refined sugar yield were obtained with the application rate of 10 tonnes BFS per hectare. Ten tonnes of BSF per hectare was the most suitable on the basis of root quality parameters and root yield. However BFS should be applied to the soil six or seven months in advance due to the high level of nitrogen released through mineralization. Ó 2003 Elsevier Science Ltd. All rights reserved. Keywords: Beer factory sludge; Sugar beet; Waste; Amendment of soil 1. Introduction There has been a considerable focus at both national and international level on the need to reduce the amount of waste and to increase the proportion of recycled materials. Farmers have long since recognized the im- portance of organic matter (OM), so agricultural waste has been used to sustain and improve the fertility of soils. Agricultural wastes––animal excreta and straw have been used for hundred years––use has more re- cently declined with advent of intensive farms with little land. Use of factory wastes has possibly recently ex- panded (Saviozzi et al., 1994; Tripepi et al., 1996; K€ ut€ uk et al., 1998; Baran et al., 2001). Those materials were traditionally burned, dumped at sea or stored in land- fills. However, in the last decades, there has been a trend to use those materials in agriculture due to an increasing demand to decrease environment pollution. Industrial wastes, especially of organic origin, have a high potential for agricultural use. Using those wastes in arid and semi-arid regions, where the OM content of soils is rather low, will contribute on one hand to re- ducing of environmental problems and on the other hand they will enrich the soil with OM. The gradual and rapid decrease in OM content in soils under agriculture, especially those in hot climates, may lead to the deteri- oration of their chemical and physical properties (Flaig et al., 1977). However, the positive effects of soil OM depend on its amount and composition (Clapp et al., 1986; € Unsal and Ok, 2001). The beer factory located in Ankara, has a capacity of 1.5 million hectoliter per year, and produces 5 tonnes of sludge per day. This sludge has been up to now dumped into landfill creating some environmental and manage- ment problems in the region. Whereas the use of sludge in the soil system will enhance the development of * Corresponding author. Fax: +90-312-3178465. E-mailaddress: kutuk@agri.ankara.edu.tr (C. K€ ut€ uk). 0960-8524/03/$ - see front matter Ó 2003 Elsevier Science Ltd. All rights reserved. doi:10.1016/S0960-8524(03)00089-0 Bioresource Technology 90 (2003) 75–80