HARVEST MECHANISATION OF ARUNDO DONAX L. IN SPAIN M.D. Curt 1 , M. Sanz 1 , F. Mosquera 1 , P.V. Mauri 2 , A. Plaza 2 , P.L. Aguado 1 and J. Fernández 1 1 Dpt. Producción Vegetal: Botánica y Protección Vegetal. Universidad Politécnica de Madrid. 28040, Madrid. (Spain) 2 Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario (IMIDRA). Alcalá de Henares (Spain) ABSTRACT: Mechanisation has been recognised as a key point for the promotion of dedicated energy crops like Arundo donax L. This work reports the performance of commercial machinery modified and assembled by a Spanish manufacturer of agricultural machinery, which was tested in an arundo crop for biomass. Operational speeds and other data gathered during the harvesting tests are given in this article. Actual yield in baled biomass and biomass properties after 8-month storage in open field were determined as well. Results show that the strategy of two-step harvesting: stalk cutting & crushing and biomass collection and baling with this specific machinery is feasible in wintertime. Physical, energy and chemical properties of baled biomass did not change after 8 months. On the whole, the machinery used in these tests performed well; however, the working height of the baler should be improved to avoid damages to irrigation pipes. Keywords: Arundo donax, grass, harvesting, energy crops. 1 INTRODUCTION Arundo donax L., commonly known as giant reed or arundo, is a perennial rhizomatous grass originated from the circum-Mediterranean-Asian area, but widely spread in many other areas of the World. Because of its habit, vigorous growth, hardiness, competitiveness and high productivity, arundo has received much attention from researchers. On the one hand, arundo has been considered as an invasive species in riparian ecosystems [1]; on the other hand, it has been proposed as an energy crop for biomass production in marginal abandoned or set-aside agricultural lands [2 ]. Hence, arundo has been studied as an energy crop in Europe since the decade of 1980 and relevant contributions to the knowledge of the potential of arundo for biomass production have been made [3, 4, 5, 6]. Mechanisation has been recognised as a key point for the development of dedicated energy crops. It has an important effect on the energy and economic balance of the crop and also on the amount of biomass actually harvested (actual crop yield) [7]. For instance, in the area of energy crops for solid biomass, significant progress has been made with short rotation coppice [8] and miscanthus [9]. On this regard, Arundo donax L. shares some features with these two types of crops, particularly with miscanthus: winter harvest, tall stems (culms or canes), basal stem diameter ~ 3 cm, biomass made up of stems (major proportion) and leaves, high yields in good hydric conditions [10]. Several trials of mechanised harvest of arundo biomass have been conducted in Europe. It has been shown that there is a risk that arundo stumps cause punctures in the tires when the cut is clean (mower- fodder-loader combine machine) and stumps are hard and slanting [11]. There are also reports of tests with prototypes designed for short rotation coppice [12] and forage harvesters like Claas model Jaguar 850 [13]. Recently, harvest mechanisation of perennial grasses, including arundo, has been acknowledged as a subject of research within the framework of the OPTIMA European Project (KBBE.2011.3.1-02) [14]. This work reports the results of an experiment undertaken in Alcalá de Henares (Spain) in order to gain knowledge on the performance of common machinery modified by a Spanish manufacturer of agricultural machinery for arundo harvesting. Operational speeds and other data gathered during the harvesting tests are given in this article. Actual yield of the crop (baled biomass) and properties of baled biomass after 8-month storage in open field were determined as well. 2 MATERIAL AND METHODS 2.1 Location and experiment design Field trials were located in the municipality of Alcala de Henares (Madrid, Spain), more specifically in the property ‘El Encín’ of IMIDRA (Instituto Madrileño de Investigación y Desarrollo Rural, Agrario y Alimentario), at latitude 40º31’12” N and longitude 3º18’13” W. The experiment involved two areas of work: i) cultivation of Arundo and ii) tests of machinery for Arundo harvesting, which involved several steps. The flowchart representing the step-by-step process is shown in Figure 1. Figure 1: Flowchart representing the steps of the experiment. 2.2 Crop description Soil in this experiment is classified as Haploxeralf Calcic with a sandy-clay texture, according to USDA Soil 21st European Biomass Conference and Exhibition, 3-7 June 2013, Copenhagen, Denmark 302