BioCycle October 2004, Vol. 45, No. 10, p. 55
Faced with the challenges of low organic matter and high erosion, the large agricultural industry in Andalusia, Spain is finding solutions offered by compost.
Alexis Kerner and José Marìa Álvarez

ANDALUSIA is the southern region of the Spanish peninsula whose coasts border both the Mediterranean Sea and the Atlantic Ocean. It is the largest and most populous region (pop. 7,478,432) of the country, covering 87,597 square kilometers that are divided into eight provinces: Huelva, Cadiz, Almeria, Malaga, Sevilla, Cordoba, Granada and Jaen. The landscape, dotted with olive and fruit trees, is largely dominated by agricultural activities. Regional farmers are faced with two challenges: low organic matter and erosion.
Despite some fertile soils found in the Guadalquivir River basin, many Andalusian soils contain less than one percent organic matter. These averages should be between 1.7 and 3.4 for the area. The second challenge, erosion, occurs when the lands are left bone dry after Mediterranean summers without precipitation, coupled by heavy autumn rains. Since Andalusia has a large agricultural industry that cultivates cereals, grapes, olives, citrus and a quantity of other fruits and vegetables, it becomes imperative to address these concerns. Compost has been found to be an effective solution to these and other issues the region faces.
MUNICIPAL ORGANICS AND COMPOSTING
Waste reduction is one of the challenges that compost helps resolve. Andalusia produces 3,150,000 tons of MSW (municipal solid waste) each year. Last year, 2003, the region treated 1,200,000 tons of organic matter derived from this source and created 480,000 tons of compost in 18 composting plants. The future goals for 2005 aim to compost 300,000 tons more organic material than it did in 2003 of which 585,000 tons of usable compost will be produced. During the same time frame, the government seeks to construct four more plants to process the increased quantity of material. Additionally, it intends to utilize 65 percent of its 1,250,000 tons of sludge produced annually in agriculture and soil conservation efforts. Park and garden trimmings, which amount to an estimated 1 million tons yearly, would be used as a bulking agent
To place regulations on the aforementioned wastes, the government has established a regional plan for the management of urban wastes (El Plan Territorial Regional de Gestión de Residuos Urbanos) that incorporates the European Directive 1999/31. It is important for European Union member countries to include the established community directives since it is expected that they will be following them within a specified period of time.
As a result, composting and waste recovery plants have been constructed to support composting as a means of municipal waste treatment. As noted before, composting the organic matter in the waste stream helps the region address many issues. Some of these include: high tipping fees; accumulation of organic matter in landfills; methane gas emissions; and vermin, disease, odors and fires associated with controlled dumps. In a similar way, the product is known to reduce soil erosion, desertification, and soil fertility loss, lower water contamination and lessen the need for nonrenewable resources.
COMPOST RESEARCH AND DEVELOPMENT
In 1998, the project, Research and Development of Composting Production and its Application in the Agricultural and Forestry Sectors, was established under the management of EGMASA, a public Andalusian environmental management company (www.egmasa.es). The program, financially supported by the European Regional Development Fund (ERDF), was established to give additional strength to composting production and help support its use.
The project started its research by manufacturing three distinct composts – A, B and C – cocomposting different ratios of MSW organics, WWTP (wastewater treatment plant) sludge, and park trimmings (chipped). Compost A was comprised of 25 percent sludge and 75 percent park and garden trimmings. Compost B contained 60 percent park and garden trimmings with organics from MSW. Lastly, Compost C was comprised of all three feedstocks: 25 percent sludge; 25 percent MSW organics; and 50 percent trimmings. The wood chips used were screened to obtain fragments between 2 and 15 cm before they were blended into the specified mixtures, serving as a bulking agent that aided in pile aeration and improved fermentation. The better pile conditions achieved by using the chips helped to create a better end-product and reduce odors associated with anaerobic fermentation.
Composting was done in windrows for all three types of composts. This was mainly due to its familiarity among the manufacturers involved in the project. The piles were arranged in 5.5 meters wide and 2.5 meters high windrows and were turned every 10-15 days. The windrow temperatures were monitored throughout a two-month long fermentation period. After fermentation, the material was left to mature for at least one month. According to its final destination, the compost was screened using a 24/12/4 mm mesh.
Studies were done on the feedstocks, the final-end composts, the soils where the composts were used (before and after application) as well as on the harvested plant material that had been grown using the compost. Inorganic fertilizer was used as comparison. These studies were used to demonstrate that the parameters used in determining the characteristics had values that categorized them as good quality. Table 1 shows the parameters tested for each of the three composts and their results.
Tests were also done for characteristics that could have a negative effect on the plants or the environment. An important set of chemical parameters that fit in this category is heavy metals. The heavy metal content for the composts measured lower than the established legal limits and fell within the limits outlined in the second draft of the European Commission’s working document, Biological Treatment of Biowaste from February of 2001 (http://mie.esab.upc.es/ms/lesg_working_document.PDF). The three composts, according to the European Commission limits, could be classified between class 1 and class 2. Since heavy metals can be absorbed into the plant material from contaminated soil, tests were also completed on the plant material, whose results were within suggested limits. Ecotoxicological tests on seed germination and microbiology confirmed that the composts were not harmful to the environment or plant development. Finally, each compost was tested for pathogens, weed seeds, and its maturity level. Temperatures during fermentation that ranged from 60°-70° C (140°-158° F) proved effective in killing pathogens along with weed seeds and a month of maturation showed to be an efficient amount of time for compost stabilization. When the composts were insured to be of good quality, they were tested on commonly used agricultural and forestry plants.
After three years of work, the objectives for the ERDF project were completed. However, many people that had been involved with the project wanted more information and assistance with compost. It was obvious that the project had accomplished important research but that it needed a second phase to continue presenting the information to users and manufacturers. Therefore, in 2000, the Andalusian Regional Ministry for the Environment and 10 other public and private organizations that included four research groups (IRNAS-CSIS, ENCE Group, University of Almeria, and Algarve University), two provincial councils (Seville and Jaen), two waste treatment plants (Western Malaga’s Costa del Sol Association and EMASESA), one environmental company (Terravida Limited.) and a small farmer’s organization (UPA) cooperated to financially help support the cause. To cover the additional funding necessary to carry out the project, the European LIFE initiative awarded the program with a subvention. This second phase of the program was titled “LIFE Compost Dissemination”.
FINANCIAL INSTRUMENT AND COMPOST DEMONSTRATION
The LIFE-Environment Project of the European Union describes its program as one that operates within the framework of sustainable development, contributes to the implementation, development and improvement of the European environmental norms and legislation, as well as the integration of the environmental themes in other European regulations. LIFE supports innovative techniques and methods by cofinancing demonstration projects in the following five categories: land use development and planning; water management; reduction of the environmental impact of economic activities; waste management; reduction of the environmental impact of products through an integrated product policy.
LIFE-Environment does not finance research or investment in existing technologies or infrastructure. The purpose of the program is to bridge the gap between research and development results and their large-scale application. To this end, demonstration projects based on the results of projects which have been supported under past or ongoing technological research and development programs are encouraged. The dissemination of results is essential for ensuring that innovative technologies and procedures for protecting the environment are widely applied.
The main purpose of the Compost Dissemination Project of Andalusia has been to educate and make aware the social agencies involved in the processing and application of compost so to avoid inadequate practices that deteriorate the validity of these organic materials as quality fertilizers. The LIFE Compost Dissemination’s partners are committed to carry out this propagation which aims to demonstrate that organic wastes coming from human activity are valid resources for cocomposting or mixed composting from a technical, economical and environmental point of view. In order to achieve this, the project has been designed to be accomplished in the following phases: Manufacturing of quality compost; Maintenance of the test and demonstration sites; Design and construction of the compost spreader; and construction of the compost spreader; and Dissemination of the project results.
The compost, that was manufactured in the previously described way, was tested in the following fields: reforestation, landscaping, forestry, agriculture and nurseries. Table 2 shows the fields and the corresponding number of test sites with results.
In these tests, the compost has been utilized as a topsoil substitute for gardening and landscaping, in place of traditionally applied manures for species cultivated for forestry and agriculture, and to replace potting substrate in plant nurseries. The positive results that were attained using the compost under these conditions supports the belief that the product can completely or partially replace the nonrenewable resources, peat and sphagnum moss, in plant cultivation activities, manures and decreasingly available topsoil. The results using compost have been almost always better than the usually applied methods. For example, reforestation studies demonstrated that the application of compost stimulated plant growth and improved tree survival rates. It also showed an increase of height and volume in tree cultivation that could prove valuable in lumber production. Irrigated agricultural plots likewise have shown mostly positive outcomes. Table 3 further details the results in the diverse sectors using some of the most cultivated species of the area.
FEASIBILITY AND COST-EFFECTIVE RESULTS
Apart from showing that compost use has positive results, the Project needed to prove that its application was both feasible and cost-effective. Therefore, the LIFE project, along with the technical experts from ENCE Group, set out to design, construct and demonstrate a new compost spreader that would reduce costs of application and would be able to apply compost on difficult terrain. The resulting spreader replaces the old manure and fertilizer spreaders by adjusting technology to the unique characteristics of compost and confronting challenges farmers face. The new machine is able to regulate the rate of application and the way it is applied as well as operate on slopes of 17 percent grade and irregular surfaces. Its size and easy maneuverability has been designed to allow the apparatus to pass through olive tree and other plantations where machines in the past have encountered obstacles.
As word spread about the encouraging results that were being obtained using LIFE compost, more organizations and companies wanted to join the effort by trying the product and supporting the diffusion of its information. Reacting to the demand, a network was established and set up to efficiently distribute information, as well as act as a way to exchange experiences and ideas. In addition, the project created a headquarters called the LIFE Office for Compost (Oficina LIFE del Compost) located in Seville, Spain, and an extensive project website. The website has been recently translated into English to broaden its possible audience. It also contains downloadable files about the experiments and a forum for debate. The site can be found at http://www.compostandalucia.net/.
In the future, the LIFE Project intends to continue with the activities already in progress that provide services to compost producers and users and establish new ones. One endeavor would respond to an expressed interest in finding agricultural by-products for cocomposting agro-industrial, wastewater treatment plant sludge and developing initiatives for cocomposting in ecological agriculture. Previous projects have included the promotion of domestic composting and participation in national and international forums which the program anticipates to continue supporting. Finally, it is important to mention that a plan for the management of WWTP urban biosolids will further be encouraged that would assemble the competent distinct regional administrations.
As a result of the project’s outcome, a document has been written for a program that would create a Regional Compost Center. This program would control, promote and distribute compost in the regions of Andalusia and Algarve. Its activities would keep inventory of the existing installations that produce biodegradable wastes, put together guides on the best practices for compost production and edit catalogues for its use. It would also organize the production and use of compost through the Association of Producers of Quality Compost, detail procedures to accredited laboratories that specialize in the analysis of these products and oversee product quality control within the region. Similarly, the program would support the demonstration site network and organize informative activities that include domestic and community composting. Finally, it would also incorporate composting of feedstocks that originate from agro-industrial olive oil production mills into the already involved network of producers and users and continue to be an active constituent for the distribution of compost in the region.
Alexis Kerner and José Marìa Álvarez are with Oficina LIFE del compost in Sevilla, Spain. For more information, visit www.compostandalucia.net or contact the Project LIFE Office by email at forolife@egmasa.es or write to C/ Johan G. Gutenburg s/n I Cartuja. 41092 Seville, Spain.