I am of the opinion that every farmer need a biogas digester in his or her farm whether you are into crop or animal farming. Its of immense benefits to both farmers because animal dung and rotten crops can be use as waste to produce methane gas for cooking and lighting purposes and also a slurry fertilizer is produce that is rich in NPK and ideal for crop farmers. Biogas can also be used for heating purposes for chicks in the poultry farm. I am an expert in biogas production and installation. My number is 08032843129 and my blog site is www.sazeb..com