NOVELTY - Process for biological treatment of dry agricultural waste containing cellulose, which is cereal straw (preferably rice straw) comprises: forming a pile (9) of the agricultural waste on a platform and its waterproofing; wetting and activation of the pile; aerobic pre-treatment for the bringing to temperature and hydrolysis; anaerobic treatment with recycling of percolates; maintaining the temperature by controlled feeding of air; and final aerobic treatment to evaporate excess of water.    USE - The process is useful for biological treatment of dry agricultural waste containing cellulose, which is cereal straw (preferably rice straw). The process is useful for producing biogas, which is useful in an internal combustion engine to produce electrical energy (claimed). The produced biogas is useful for generating thermal energy.    ADVANTAGE - The process provides aerobic-anaerobic treatment method for the agricultural waste, which allows elimination of the environmental problems caused by the common practice of burying or combustion of the waste on the fields. The treatment method allows recovery of the energy contained in the straw in the form of biogas, to generate thermal and/or electrical energy from renewable sources. The method is economical for application on a farm and on a large scale. The process: provides high production of biogas per quantity of biomass and suitable decomposition time for continuously feeding energy production plants; recovers organic and humic substances useful for the soil; reduces gas emissions that affect climate; eliminates gaseous emissions and polluting liquids; and minimizes consumption and total recovery of materials for building of the plant, thus requires very low investment costs and running costs.    DETAILED DESCRIPTION - Process for biological treatment of dry agricultural waste containing cellulose, which is cereal straw (preferably rice straw) comprises: forming a pile (9) of the agricultural waste on a platform and its waterproofing, where the pile: is composed of dry materials, cannot undergo aerobic or anaerobic digestion with dispersion of biogas or odors or risk of fire through self combustion; wetting and activation of the pile; aerobic pre-treatment for bringing to temperature and hydrolysis; anaerobic treatment with recycling of percolates; maintaining the temperature by controlled feeding of air and therefore with exothermic aerobic digestion, which is regulated perfectly by means of the quantity of air fed; and final aerobic treatment to evaporate excess of water. INDEPENDENT CLAIMS are included for:    (1) system for the treatment of the agricultural waste comprising a waterproof platform suitable for holding the pile of the agricultural waste collected in bales (7); means for collecting percolate and biogas placed on the platform; means for recycling the percolate and its distribution at the top of the pile; means for aspirating biogas from the top of the pile or for blowing air; and means for waterproofing the entire system; and    (2) a system for production of biogas through anaerobic digestion of cellulosic materials, in particular vegetal waste, operating in non-aqueous phase, at a perfectly controlled temperature and in vacuum, obtained by the introduction of parallel exothermic aerobic digestion processes triggered by controlled feeding of aspirated air.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic view in vertical section of a rural bioreactor.    Clay (1)    Waterproof containment membrane (2)    Layer of sand (3)    Well (5)    Bales (7)    Pile. (9)