A method for obtaining a product which contains phosphorus in a form which can be used by plants when gasifying a bulk product of at least partly organic origin accompanied by at least partial oxidation of an organic portion of the bulk product, with the following steps: a) introducing a charge of the bulk product into a reaction chamber of a reactor, b) continuous or intermittent movement of the charge, c) heating the bulk product on the top side of the charge to a temperature at which the pyrolysis of the organic portion of the bulk product occurs, d) blowing, into the charge, air or another gas mixture which contains oxygen via at least one blow-in opening in at least one tool moving continuously or intermittently through the charge, wherein the air, the gas mixture, resulting gas and/or combustion gas resulting from the combustion thereof above the charge is conducted out of the reaction chamber via at least one gas outlet opening above the charge or the air, the gas mixture and/or resulting gas is conducted out of the reaction chamber via at least one gas outlet opening in the upper quarter of the charge, wherein the resulting gas moves upwards in the charge, wherein the blowing-in of the air or the other gas mixture which contains oxygen is regulated such that the quantity of air or gas mixture is sufficient only for an incomplete oxidation of the organic portion of the bulk product in the reaction chamber, and e) feeding the bulk product into the reaction chamber from above or in the upper quarter of the charge and discharging unconverted bulk product and/or product which has resulted from incomplete or at least partial conversion of the organic portion of the bulk product from the reaction chamber below or at the bottom end of the charge, wherein the bulk product is moved downwards in the reaction chamber by being discharged. a) introducing a charge of the bulk product into a reaction chamber of a reactor, b) continuous or intermittent movement of the charge, c) heating the bulk product on the top side of the charge to a temperature at which the pyrolysis of the organic portion of the bulk product occurs, d) blowing, into the charge, air or another gas mixture which contains oxygen via at least one blow-in opening in at least one tool moving continuously or intermittently through the charge, wherein the air, the gas mixture, resulting gas and/or combustion gas resulting from the combustion thereof above the charge is conducted out of the reaction chamber via at least one gas outlet opening above the charge or the air, the gas mixture and/or resulting gas is conducted out of the reaction chamber via at least one gas outlet opening in the upper quarter of the charge, wherein the resulting gas moves upwards in the charge, wherein the blowing-in of the air or the other gas mixture which contains oxygen is regulated such that the quantity of air or gas mixture is sufficient only for an incomplete oxidation of the organic portion of the bulk product in the reaction chamber, and e) feeding the bulk product into the reaction chamber from above or in the upper quarter of the charge and discharging unconverted bulk product and/or product which has resulted from incomplete or at least partial conversion of the organic portion of the bulk product from the reaction chamber below or at the bottom end of the charge, wherein the bulk product is moved downwards in the reaction chamber by being discharged.